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Manual Chapter: Health and Performance Monitors
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The following pages contain descriptions of BIG-IP® Local Traffic ManagerTM health and performance monitors. These descriptions are presented by name, in alphabetical order.
Important: If you configure a performance monitor, such as the SNMP DCA, Real Server, or WMI monitor type, you should also configure a health monitor. Configuring a health monitor ensures that the BIG-IP system reports accurate node availability status.
Important: When defining values for custom monitors, make sure you avoid using any values that are on the list of reserved keywords. For more information, see solution number 3653 (for 9.0+ systems) on the AskF5SM Knowledge Base, http://support.f5.com.
More specifically, after you have configured a Diameter monitor, you can associate the monitor with a load balancing pool. The BIG-IP system then attempts to establish a TCP connection with a server in the pool. After successfully establishing a connection, the Diameter monitor sends a Capabilities-Exchanging-Request (CER) message to the server. The monitor then waits to receive a Capabilities-Exchanging-Answer (CEA) message, as well as a result code of DIAMETER_SUCCESS (2001).
Figure A.1 shows the settings and default values of a Diameter-type monitor.
Type Diameter
Host IP Address * All Addresses
Product Name F5 BIG-IP
Name
Specifies a unique name for the custom monitor, such as my_diameter_monitor.
Type
Specifies the type of monitor you are creating.
Interval
Specifies the frequency at which the system issues the monitor check. The default is 10 seconds.
Timeout
Specifies the number of seconds in which the node must respond to the monitor request. The default is 31 seconds. If the node responds within the set time period, the node is considered to be up. If the node does not respond within the set time period, the node is considered to be down. The Timeout value should be three times the Interval value, plus one second.
Manual Resume
Using the Manual Resume setting, you can manually designate a resource as being available. For more information, see Chapter 13, Configuring Monitors.
Time Until Up
Delays the marking of a pool member or node as up for some number of seconds after receiving the first correct response. When this attribute is set to 0 (the default value), the BIG-IP system marks the resource as up immediately after receiving the first correct response.
Origin Host
Specifies the IP address on the BIG-IP system that generates the request to the servers. If you provide no value for this setting, the system uses the self IP address on the VLAN that generates the request to the server.
Origin Realm
Specifies the realm of the BIG-IP system that generates the request to the servers. By default, this value is f5.com.
Host IP Addresses
The Host IP Addresses setting specifies the destination IP address that the monitor checks, with the default value * All Addresses.
Vendor ID
Identifies the vendor that generates the request to the servers. By default, this value is F5.
Product Name
Specifies the name of the product used to monitor the servers running the Diameter service. By default, this value is F5 BIG-IP.
Auth Application ID
Advertises support for the Authentication and Authorization portion of an application. The Auth Application ID must also be present in all Authentication and/or Authorization messages that are defined in a separate Diameter specification and have an Application ID assigned. This value is disabled by default. If enabled, any value that you specify must be a 32-bit unsigned value.
Acct Application ID
Advertises support for the Accounting portion of an application. The Acct Application ID must also be present in all Accounting messages. Exactly one of the Auth Application ID attribute-value pairs and Acct Application ID attribute-value pairs can be present.
Vendor Specific Application ID
Advertises support of a vendor-specific Diameter application. Exactly one of the Vendor Specific Auth Application ID attribute-value pairs and Vendor Specific Acct Application ID attribute-value pairs can be present. This value must also be present as the first attribute-value pair in all experimental commands defined in the vendor-specific application.
Vendor Specific Vendor ID
Specifies an attribute-value pair associated with the Vendor Specific Application ID monitor setting.
Vendor Specific Auth Application ID
Specifies an attribute-value pair associated with the Vendor Specific Application ID monitor setting.
Vendor Specific Acct Application ID
Specifies an attribute-value pair associated with the Vendor Specific Application ID monitor setting.
Using an External type of monitor, you can create your own monitor type. To do this, you create a custom External-type monitor and within it, specify a user-supplied monitor to run.
Figure A.2 shows the settings and default values of an External-type monitor.
Type External
Alias Address * All Addresses
Alias Service Port * All Ports
Name
Specifies a unique name for the custom monitor, such as my_external_monitor.
Type
Specifies the type of monitor you are creating.
Interval
Specifies the frequency at which the system issues the monitor check. The default is 5 seconds.
Timeout
Specifies the number of seconds in which the node must respond to the monitor request. The default is 16 seconds. If the node responds within the set time period, the node is considered to be up. If the node does not respond within the set time period, the node is considered to be down. The Timeout value should be three times the Interval value, plus one second.
Manual Resume
Using the Manual Resume setting, you can manually designate a resource as being available. For more information, see Chapter 13, Configuring Monitors.
Time Until Up
Delays the marking of a pool member or node as up for some number of seconds after receiving the first correct response. When this attribute is set to 0 (the default value), the BIG-IP system marks the resource as up immediately after receiving the first correct response. For more information, see Chapter 13, Configuring Monitors.
External Program
It is the External Program setting that you use to specify the executable name of your user-supplied monitor program. An External-type monitor searches the directory /config/monitors for that monitor name.
Arguments
The Arguments setting allows you to specify any command-line arguments that are required.
Variables
This setting specifies the variables that an External monitor requires, namely a Name/Value pair.
Alias Address and Alias Service Port
The Alias Address setting specifies the destination IP address that the monitor checks, with the default value * All Addresses. For more information, see Chapter 13, Configuring Monitors.
Figure A.3 shows the settings and default values of a FirePass-type monitor.
Type External
Cipher List HIGH:!ADH
Alias Address *All Addresses
Name
Specifies a unique name for the custom monitor, such as my_firepass_monitor.
Type
Specifies the type of monitor you are creating.
Interval
Specifies the frequency at which the system issues the monitor check. The default is 5 seconds.
Timeout
Specifies the number of seconds in which the node must respond to the monitor request. The default is 16 seconds. If the node responds within the set time period, the node is considered to be up. If the node does not respond within the set time period, the node is considered to be down. Also, if the node responds with a RESET packet, the system flags the node as down immediately, without waiting for the timeout interval to expire. Note that the Timeout setting should be three times the Interval setting, plus 1 second.
Manual Resume
Using the Manual Resume setting, you can manually designate a resource as being available. For more information, see Chapter 13, Configuring Monitors.
Time Until Up
Delays the marking of a pool member or node as up for some number of seconds after receiving the first correct response. When this attribute is set to 0 (the default value), the BIG-IP system marks the resource as up immediately after receiving the first correct response. For more information, see Chapter 13, Configuring Monitors.
Cipher List
If you do not specify a cipher list, the monitor uses the default cipher list DEFAULT:+SHA:+3DES:+kEDH.
Max Load Average
Specifies the number that the monitor uses to mark the FirePass system up or down. The system compares this setting to a one-minute average of the FirePass system load. When the FirePass system-load average falls within the specified Max Load Average value, the monitor marks the FirePass system up. When the average exceeds the setting, the monitor marks the system down. The default value is 12.0.
Concurrency Limit
Specifies the maximum percentage of licensed connections currently in use under which the monitor marks the FirePass system up. As an example, a setting of 95 percent means that the monitor marks the FirePass system up until 95 percent of licensed connections are in use. When the number of in-use licensed connections exceeds 95 percent, the monitor marks the FirePass system down The default value is 95.
User Name and Password
If there is no password security, you must use blank strings [""] for the Username and Password settings.
Alias Address and Alias Service Port
The Alias Address setting specifies the destination IP address that the monitor checks, with the default value * All Addresses. For more information, see Chapter 13, Configuring Monitors.
Using an FTP type of monitor, you can monitor File Transfer Protocol (FTP) traffic. A monitor of this type attempts to download a specified file to the /var/tmp directory, and if the file is retrieved, the check is successful. Note that once the file has been successfully downloaded, the BIG-IP system does not save it.
An FTP monitor specifies a user name, a password, and a full path to the file to be downloaded.
Figure A.4 shows the settings and default values of an FTP-type monitor.
Name ""
Type FTP
Mode Passive
Alias Address * All Addresses
Alias Service Port * All Ports
Name
Specifies a unique name for the custom monitor, such as my_ftp_monitor.
Type
Specifies the type of monitor you are creating.
Interval
Specifies the frequency at which the system issues the monitor check. The default is 10 seconds.
Timeout
Specifies the number of seconds in which the node must respond to the monitor request. The default is 31 seconds. If the node responds within the set time period, the node is considered to be up. If the node does not respond within the set time period, the node is considered to be down. The Timeout value should be three times the Interval value, plus one second.
Manual Resume
Using the Manual Resume setting, you can manually designate a resource as being available. For more information, see Chapter 13, Configuring Monitors.
Time Until Up
Delays the marking of a pool member or node as up for some number of seconds after receiving the first correct response. When this attribute is set to 0 (the default value), the BIG-IP system marks the resource as up immediately after receiving the first correct response. For more information, see Chapter 13, Configuring Monitors.
Alias Address and Alias Service Port
The Alias Address setting specifies the destination IP address that the monitor checks, with the default value * All Addresses. For more information, see Chapter 13, Configuring Monitors.
A Gateway ICMP type of monitor has a special purpose. You use this monitor for a pool that implements gateway failsafe for high availability.
A Gateway ICMP monitor functions the same way as an ICMP monitor, except that you can apply a Gateway ICMP monitor to a pool member. (Remember that you can apply an ICMP monitor to a node only and not a pool member.) Figure A.5 shows the settings and their values for the pre-configured gateway_icmp monitor.
Figure A.5 The gateway_icmp pre-configured monitor
Name ""
Type Gateway ICMP
Alias Address * All Addresses
Alias Service Port * All Ports
Name
Specifies a unique name for the custom monitor, such as my_gw_icmp_monitor.
Type
Specifies the type of monitor you are creating.
Interval
Specifies the frequency at which the system issues the monitor check. The default is 5 seconds.
Timeout
Specifies the number of seconds in which the node must respond to the monitor request. The default is 16 seconds. If the node responds within the set time period, the node is considered to be up. If the node does not respond within the set time period, the node is considered to be down. The Timeout value should be three times the Interval value, plus one second.
Manual Resume
Using the Manual Resume setting, you can manually designate a resource as being available. For more information, see Chapter 13, Configuring Monitors.
Time Until Up
Delays the marking of a pool member or node as up for some number of seconds after receiving the first correct response. When this attribute is set to 0 (the default value), the BIG-IP system marks the resource as up immediately after receiving the first correct response. For more information, see Chapter 13, Configuring Monitors.
Transparent
The Transparent mode is an option for this type of monitor. When you set this mode to Yes, the monitor pings the node with which the monitor is associated. For more information about Transparent mode, see Chapter 13, Configuring Monitors.
Alias Address and Alias Service Port
The Alias Address setting specifies the destination IP address that the monitor checks, with the default value * All Addresses. For more information, see Chapter 13, Configuring Monitors.
You can use an HTTP type of monitor to check the status of Hypertext Transfer Protocol (HTTP) traffic. Like a TCP monitor, an HTTP monitor attempts to receive specific content from a web page, and unlike a TCP monitor, may send a user name and password. Figure A.6 shows the settings of the pre-configured monitor http.
Figure A.6 The http pre-configured monitor
Name ""
Type HTTP
Alias Address * All Addresses
Alias Service Port * All Ports
Name
Specifies a unique name for the custom monitor, such as my_http_monitor.
Type
Specifies the type of monitor you are creating.
Interval
Specifies the frequency at which the system issues the monitor check. The default is 5 seconds.
Timeout
Specifies the number of seconds in which the node must respond to the monitor request. The default is 16 seconds. If the node responds within the set time period, the node is considered to be up. If the node does not respond within the set time period, the node is considered to be down. The Timeout value should be three times the Interval value, plus one second.
Manual Resume
Using the Manual Resume setting, you can manually designate a resource as being available. For more information, see Chapter 13, Configuring Monitors.
Time Until Up
Delays the marking of a pool member or node as up for some number of seconds after receiving the first correct response. When this attribute is set to 0 (the default value), the BIG-IP system marks the resource as up immediately after receiving the first correct response. For more information, see Chapter 13, Configuring Monitors.
Send String and Receive String
This type of monitor takes a Send String value and a Receive String value. If the Send String value is blank and a connection can be made, the service is considered up. A blank Receive String value matches any response. The check is successful when the content matches the Receive String value. Note that you can specify the value of a response header as the Receive String value. For example, the value of the Receive String attribute can be 404 Object Not Found. Note that the Send String and Receive String attributes are case-insenstive (that is, they ignore case).
User Name and Password
If there is no password security, you must use blank strings [""] for the Username and Password settings.)
Transparent and Reverse
Both Transparent and Reverse modes are options. For more information about Transparent and Reverse modes, see Chapter 13, Configuring Monitors.
You use an HTTPS type of monitor to check the status of Hypertext Transfer Protocol Secure (HTTPS) traffic. An HTTPS type of monitor attempts to receive specific content from a web page protected by SSL security. The check is successful when the content matches the Receive String value.
The BIG-IP system provides two pre-configured HTTPS monitors, https and https_443. Figure A.7 shows the settings of the pre-configured monitor https, and Figure A.8 shows the settings of the pre-configured https_443.
Figure A.7 The https pre-configured monitor
Name ""
Type HTTPS
Alias Address * All Addresses
Alias Service Port * All Ports
Figure A.8 The https_443 pre-configured monitor
Name ""
Type HTTPS_443
Alias Address * All Addresses
Name
Specifies a unique name for the custom monitor, such as my_https_monitor or my_https_443_monitor.
Type
Specifies the type of monitor you are creating.
Interval
Specifies the frequency at which the system issues the monitor check. The default is 5 seconds.
Timeout
Specifies the number of seconds in which the node must respond to the monitor request. The default is 16 seconds. If the node responds within the set time period, the node is considered to be up. If the node does not respond within the set time period, the node is considered to be down. The Timeout value should be three times the Interval value, plus one second.
Manual Resume
Using the Manual Resume setting, you can manually designate a resource as being available. For more information, see Chapter 13, Configuring Monitors.
Time Until Up
Delays the marking of a pool member or node as up for some number of seconds after receiving the first correct response. When this attribute is set to 0 (the default value), the BIG-IP system marks the resource as up immediately after receiving the first correct response. For more information, see Chapter 13, Configuring Monitors.
Send String and Receive String
This type of monitor takes a Send String value and a Receive String value. If the Send String value is blank and a connection can be made, the service is considered up. A blank Receive String value matches any response. The check is successful when the content matches the Receive String value. Note that you can specify the value of a response header as the Receive String value. For example, the value of the Receive String attribute can be 404 Object Not Found. Note that the Send String and Receive String attributes are case-insenstive (that is, they ignore case).
Cipher List
If you do not specify a cipher list, the monitor uses the default cipher list DEFAULT:+SHA:+3DES:+kEDH.
User Name and Password
If there is no password security, you must use blank strings [""] for the Username and Password settings.)
Compatibility
When you set the Compatibility setting to Enabled, this sets the SSL options to ALL.
Client Certificate
You use the Client Certificate setting to specify a certificate file that the monitor then presents to the server.
Transparent and Reverse
Both Transparent and Reverse modes are options. For more information about Transparent and Reverse modes, see Chapter 13, Configuring Monitors.
Alias Address and Alias Service Port
The Alias Address setting specifies the destination IP address that the monitor checks, with the default value * All Addresses. For more information, see Chapter 13, Configuring Monitors.
Using an ICMP type of monitor, you can use Internet Control Message Protocol (ICMP) to make a simple node check. The check is successful if the monitor receives a response to an ICMP_ECHO datagram. Figure A.9 shows the settings and their values for the pre-configured monitor icmp.
Figure A.9 The icmp pre-configured monitor
Name ""
Type ICMP
Alias Address * All Addresses
Name
Specifies a unique name for the custom monitor, such as my_icmp_monitor.
Type
Specifies the type of monitor you are creating.
Interval
Specifies the frequency at which the system issues the monitor check. The default is 5 seconds.
Timeout
Specifies the number of seconds in which the node must respond to the monitor request. The default is 16 seconds. If the node responds within the set time period, the node is considered to be up. If the node does not respond within the set time period, the node is considered to be down. The Timeout value should be three times the Interval value, plus one second.
Manual Resume
Using the Manual Resume setting, you can manually designate a resource as being available. For more information, see Chapter 13, Configuring Monitors.
Time Until Up
Delays the marking of a node as up for some number of seconds after receiving the first correct response. When this attribute is set to 0 (the default value), the BIG-IP system marks the resource as up immediately after receiving the first correct response. For more information, see Chapter 13, Configuring Monitors.
Transparent
The Transparent mode is an option for this type of monitor. When you set this mode to Yes, the monitor pings the node with which the monitor is associated. For more information about Transparent mode, see Chapter 13, Configuring Monitors.
Alias Address
The Alias Address setting specifies the destination IP address that the monitor checks, with the default value * All Addresses. For more information, see Chapter 13, Configuring Monitors.
With an IMAP type of monitor, you can check the status of Internet Message Access Protocol (IMAP) traffic. An IMAP monitor is essentially a POP3 type of monitor with the addition of the Folder setting. The check is successful if the monitor is able to log into a server and open the specified mail folder.
Figure A.10 shows the settings and default values of an IMAP-type monitor.
Name ""
Type IMAP
Folder INBOX
Alias Address * All Addresses
Alias Service Port * All Ports
Name
Specifies a unique name for the custom monitor, such as my_imap_monitor.
Type
Specifies the type of monitor you are creating.
Interval
Specifies the frequency at which the system issues the monitor check. The default is 5 seconds.
Timeout
Specifies the number of seconds in which the node must respond to the monitor request. The default is 16 seconds. If the node responds within the set time period, the node is considered to be up. If the node does not respond within the set time period, the node is considered to be down. The Timeout value should be three times the Interval value, plus one second.
Manual Resume
Using the Manual Resume setting, you can manually designate a resource as being available. For more information, see Chapter 13, Configuring Monitors.
Time Until Up
Delays the marking of a pool member or node as up for some number of seconds after receiving the first correct response. When this attribute is set to 0 (the default value), the BIG-IP system marks the resource as up immediately after receiving the first correct response. For more information, see Chapter 13, Configuring Monitors.
User Name and Password
An IMAP monitor requires that you specify a user name and password.
Folder
The Folder setting specifies the mail folder that the monitor attempts to open when the monitor logs into a server. The check is successful if the monitor is able to log on to the server and open the specified mail folder.
Alias Address and Alias Service Port
The Alias Address setting specifies the destination IP address that the monitor checks, with the default value * All Addresses. For more information, see Chapter 13, Configuring Monitors.
Debug
The Debug setting specifies whether the monitor sends error messages and additional information to a log file created and labeled specifically for the monitor. Possible values for the Debug setting are No and Yes. The default setting is No, which specifies that the system does not redirect error messages and additional information related to this monitor. The Yes setting specifies that the system redirects error messages and additional information to the /var/log/<monitor_type>_<ip_address>.<port>.log file. You can use the log information to help diagnose and troubleshoot unsuccessful health checks.
Note: Servers to be checked by an IMAP monitor typically require special configuration to maintain a high level of security, while also allowing for monitor authentication.
With an Inband type of monitor, the BIG-IP system performs passive monitoring as part of client requests. Replacing the need to write an iRule to perform passive monitoring, an Inband monitor works with either a Standard or a Performance (Layer 4) type of virtual server.
When you configure an Inband type of monitor, the monitor, when acting as a client, attempts to connect to a pool member and behaves as follows:
If the pool member does not respond to a connection request after a user-specified number of tries within a user-specified time period, the monitor marks the pool member as down.
After the monitor has marked the pool member as down, and after a user-specified amount of time has passed, the monitor tries again to connect to the pool member (if so configured).
Figure A.11 shows the settings and default values for an Inband-type monitor.
Name ""
Type Inband
Name
Specifies a unique name for the custom monitor, such as my_inband_monitor.
Type
Specifies the type of monitor you are creating.
Failures
The Failures setting specifies the number of failed responses that a pool member may send in the defined failure interval before the monitor marks the pool member down. The total number of failures can be any combination of failed connection attempts or failures to return data within the interval specified in the Response Time setting. The default value is 3. Note that systems with multiple tmm processes use a per-process number to calculate failures, depending on the specified load balancing method. For example, for the Round Robin load balancing method, if there are N tmm processes and M pool members, and the Failures setting is set to L, then up to N*M*L+1 failures can occur before the system marks the node as down.
Failure Interval
The Failure Interval setting specifies an interval, in seconds. If the given number of failures specified in the Failures setting occurs within this interval, the system marks the pool member as being unavailable.
Response Time
The Response Time setting specifies an amount of time, in seconds. If the pool member does not respond with data after this amount of time has passed, the number of failures in this interval increments by 1. Specifying a value of 0 disables this setting.
Retry Time
The Retry Time setting specifies the amount of time in seconds after the pool member has been marked unavailable before the system tries again to connect to the pool member. A successful connection causes the monitor to mark the pool member as up. Specifying a value of 0 disables this setting.
An Inband monitor can be associated with these two types of virtual servers only: Standard and Performance (Layer 4).
The virtual server Protocol setting must be set to TCP.
The virtual server HTTP Profile setting must be set to either http, None, or the name of a custom HTTP profile.
Table A.1 shows the differences in specific system behaviors that result from implementing an Inband monitor with three different virtual server configurations.
If you configure an Inband monitor and associate it with a Performance (Layer 4) type of virtual server, a passive failure occurs when:
A tmm instance receives a RESET from the server.
The client does not receive a response from the server before the value of the Inband monitor Response Time setting expires (if the value is non-zero).
After a pool member has been marked down by the Inband monitor for the number of seconds specified in the Retry Time setting (if the value is non-zero), the pool member becomes eligible to receive a request. A pool member is marked up when the client is able to successfully establish and complete a connection to the pool member.
If you configure an Inband monitor and associate it with a Standard type of virtual server that does not reference an HTTP type of profile, a passive failure occurs when a connection is established with the pool member, or the pool member is responding to requests (or both), and the maximum retransmit times specified in the TCP profile are exceeded.
After a pool member has been marked down by the Inband monitor for the number of seconds specified in the Retry Time setting (if the value is non-zero), the pool member becomes eligible to receive a request. If the client is able to successfully establish a connection with the pool member, the pool member is marked up when the connection is completed.
If you configure an Inband monitor and associate it with a Standard type of virtual server that references an HTTP type of profile, a passive failure occurs when:
A connection is established with the pool member, or the pool member is responding to requests (or both), and the maximum retransmit times specified in the TCP profile are exceeded.
The client does not receive a response from the server before the value of the Inband monitor Response Time setting expires (if set to non-zero).
After a pool member has been marked down by the Inband monitor for the number of seconds specified in the Retry Time setting (if the value is non-zero), the pool member becomes eligible to receive a request. After successfully responding to a client request, the pool member is marked up.
If the clustered multi-processing (CMP) feature is enabled on the BIG-IP system, the number of failures that can occur within the specified Inband monitor failure interval before a pool member is marked as down is computed on each tmm instance.
For example, if the Failures and Failure Interval settings of the Inband monitor are set to 3 and 30 respectively (the default values), then the number of failures that must occur before a pool member is marked as down differs depending on whether CMP is enabled on the system:
Without CMP (that is, only one instance of tmm is running), then three passive failures must occur within 30 seconds for the monitor to report the pool member as down.
With CMP (for example, two instances of tmm are running), then three passive failures must occur on only one of the tmm instances for the monitor to report the pool member as down. However, if client requests are distributed in round robin fashion between the two tmm instances, then six client request failures must occur for the monitor to report a pool member as down.
An LDAP type of monitor checks the status of Lightweight Directory Access Protocol (LDAP) servers. The LDAP protocol implements standard X.500 for email directory consolidation. A check is successful if entries are returned for the base and filter specified. An LDAP monitor requires a user name, a password, and base and filter strings. Figure A.12 shows the settings and default values of an LDAP-type monitor.
Name ""
Type LDAP
Alias Address * All Addresses
Alias Service Port * All Ports
Name
Specifies a unique name for the custom monitor, such as my_ldap_monitor.
Type
Specifies the type of monitor you are creating.
Interval
Specifies the frequency at which the system issues the monitor check. The default is 10 seconds.
Timeout
Specifies the number of seconds in which the node must respond to the monitor request. The default is 31 seconds. If the node responds within the set time period, the node is considered to be up. If the node does not respond within the set time period, the node is considered to be down. The Timeout value should be three times the Interval value, plus one second.
Manual Resume
Using the Manual Resume setting, you can manually designate a resource as being available. For more information, see Chapter 13, Configuring Monitors.
Time Until Up
Delays the marking of a pool member or node as up for some number of seconds after receiving the first correct response. When this attribute is set to 0 (the default value), the BIG-IP system marks the resource as up immediately after receiving the first correct response. For more information, see Chapter 13, Configuring Monitors.
User Name and Password
The User Name setting specifies a distinguished name, that is, an LDAP-format user name.
Base
The Base setting specifies the starting place in the LDAP hierarchy from which to begin the query.
Filter
The Filter setting specifies an LDAP-format key of the search item.
Security
The Security setting specifies the security protocol to be used. Acceptable values are SSL, TLS, or None.
Mandatory Attributes
The Mandatory Attributes setting affects the way that the system conducts the filter search. When the value is No, the system performs a one-level search for attributes, and if the search returns no attributes, the node is reported as up. When the value is Yes, the system performs a subtree search, and if the search returns no attributes, the node is not reported as up.
Chase Referrals
Specifies whether, upon receipt of an LDAP referral entry, the target follows (or chases) that referral. The default is Yes. A value of No specifies that the system treats a referral entry as a normal entry and refrains from querying remote LDAP servers pointed to by the referral entry. No is the recommended value for this setting. A value of Yes specifies that when the system receives a referral entry from a LDAP server query, the system queries the remote LDAP servers pointed to by the referral entry. If the referral query is unsuccessful, the system marks the monitored LDAP server as unavailable.
Alias Address and Alias Service Port
The Alias Address setting specifies the destination IP address that the monitor checks, with the default value * All Addresses. For more information, see Chapter 13, Configuring Monitors.
Debug
The Debug setting specifies whether the monitor sends error messages and additional information to a log file created and labeled specifically for the monitor. Possible values for the Debug setting are No and Yes. The default setting is No, which specifies that the system does not redirect error messages and additional information related to this monitor. The Yes setting specifies that the system redirects error messages and additional information to the /var/log/<monitor_type>_<ip_address>.<port>.log file. You can use the log information to help diagnose and troubleshoot unsuccessful health checks.
For an LDAP monitor to work properly, the BIG-IP system must be able to perform a reverse DNS lookup on the address of the LDAP or LDAPS node. This reverse lookup allows the BIG-IP system to check the host name of the node's address when it verifies the SSL certificate. An external DNS server does not work with this type of monitor.
The reverse DNS lookup requirement applies to both LDAP and LDAPS nodes, even though LDAP does not require the use of an SSL certificate.
A Module Score type of monitor enables global and local traffic management systems to load balance in a proportional manner to local traffic management virtual servers associated with the Web Accelerator and Application Security Manager modules. When you configure a Module Score type of monitor, the local traffic management system uses SNMP to pull the gtm_score values from the downstream virtual servers and set the dynamic ratios on the associated upstream local traffic management pool members or nodes.
More specifically, the Module Score monitor retrieves the gtm_score values from the virtual server and the gtm_vs_score values associated with the virtual server. Then, if a pool name is not specified, this monitor sets the dynamic ratio on the node that is associated with the virtual server.
The BIG-IP system uses the lowest non-zero value of the gtm_vs_score values to set the dynamic ratio. If all gtm_vs_score values are zero, then the gtm_score value is used to set the dynamic ratios. If you specify a pool name in the monitor definition, then the dynamic ratio is set on the pool member. Figure A.13 shows the settings and default values for a Module Score monitor.
Name ""
Type Module Score
Name
Specifies a unique name for the custom monitor, such as my_module_score_monitor.
Type
Specifies the type of monitor you are creating.
Interval
Specifies the frequency at which the system issues the monitor check. The default is 10 seconds.
Timeout
Specifies the number of seconds in which the node must respond to the monitor request. The default is 30 seconds. If the node responds within the set time period, the node is considered to be up. If the node does not respond within the set time period, the node is considered to be down.
Manual Resume
Using the Manual Resume setting, you can manually designate a resource as being available. For more information, see Chapter 13, Configuring Monitors.
SNMP IP Address
In configuring a Module Score monitor, you must explicitly specify a value for the Name and the SNMP IP Address settings.
Pool Name
You need only specify a pool name if you want the system to set dynamic ratios on a pool member instead of on the associated node for the pool member.
Note: If you want to distribute traffic to a cluster of WebAccelerator or Application Security Module virtual servers, you must create a separate custom Module Score monitor for each back-end local traffic management system.
You use an MSSQL type of monitor to perform service checks on Microsoft® SQL Server-based services such as Microsoft® SQL Server versions 6.5 and 7.0.
Note: The BIG-IP system includes the JDBC JavaTM Archive (JAR) files that are necessary to use an MSSQL monitor.
Figure A.14 shows the settings and default values of an MSSQL-type monitor.
Name ""
Type mssql
Alias Address * All Addresses
Alias Service Port * All Ports
Name
Specifies a unique name for the custom monitor, such as my_mssql_monitor.
Type
Specifies the type of monitor you are creating.
Interval
Specifies the frequency at which the system issues the monitor check. The default is 30 seconds.
Timeout
Specifies the number of seconds in which the node must respond to the monitor request. The default is 91 seconds. If the node responds within the set time period, the node is considered to be up. If the node does not respond within the set time period, the node is considered to be down. The Timeout value should be three times the Interval value, plus one second.
Manual Resume
Using the Manual Resume setting, you can manually designate a resource as being available. For more information, see Chapter 13, Configuring Monitors.
Time Until Up
Delays the marking of a pool member or node as up for some number of seconds after receiving the first correct response. When this attribute is set to 0 (the default value), the BIG-IP system marks the resource as up immediately after receiving the first correct response. For more information, see Chapter 13, Configuring Monitors.
Send String
The Send String setting is optional and specifies a SQL query statement that the BIG-IP system should send to the server. Examples are SELECT * FROM sales and SELECT FirstName, LastName From Employees. If you configure the Send String setting, you can also configure the Receive String, Receive Row, and Receive Column settings.
Receive String
The Receive String setting is an optional parameter that specifies the value expected to be returned for the row and column specified with the Receive Row and Receive Column settings. An example of a Receive String value is ALAN SMITH. You can only configure this setting when you configure the Send String setting.
Database
The Database setting specifies the name of the data source on the Microsoft® SQL-based server. Examples are sales and hr.
Receive Row
The Receive Row setting is optional, and is useful only if the Receive String setting is specified. This setting specifies the row in the returned table that contains the Receive String value. You can only configure this setting when you configure the Send String and Receive String settings.
Receive Column
The Receive Column setting is optional and is useful only if the Receive String setting is specified. This setting specifies the column in the returned table that contains the Receive String value. You can configure this setting only when you configure the Send String and Receive String settings.
Count
The Count setting specifies how the system handles open connections for monitor instances. The default is 0. By default, when you assign instances of this monitor to a resource, the system keeps the connection to the database open. For more information, see the BIG-IP Configuration utility online help.
Alias Address and Alias Service Port
The Alias Address setting specifies the destination IP address that the monitor checks, with the default value * All Addresses. For more information, see Chapter 13, Configuring Monitors.
Debug
The Debug setting specifies whether the monitor sends error messages and additional information to a log file created and labeled specifically for the monitor. Possible values for the Debug setting are No and Yes. The default setting is No, which specifies that the system does not redirect error messages and additional information related to this monitor. The Yes setting specifies that the system redirects error messages and additional information to the /var/log/<monitor_type>_<ip_address>.<port>.log file. You can use the log information to help diagnose and troubleshoot unsuccessful health checks.
If an MSSQL monitor cannot log in to the server, and you have checked that the specified IP address and port number or service are correct, try the following:
Verify that you can log in using another tool.
For example, the server program Microsoft Windows® NT® SQL Server version 6.5 includes a client program named ISQL/w. This client program performs simple logins to SQL servers. Use this program to test whether you can log in to the server using the ISQL/w program.
Add logon accounts using the Microsoft® SQL Enterprise Manager.
On the Microsoft® SQL Server, you can run the SQL Enterprise Manager to add login accounts. When first entering the SQL Enterprise Manager, you may be prompted for the SQL server that you want to manage.

You can register servers by entering the machine name, user name, and password. If these names are correct, the server becomes registered and you are then able to click an icon for the server. When you expand the subtree for the server, there is an icon for login accounts.

Beneath this subtree, you can find the SQL logins. Here, you can change passwords or add new logons by right-clicking the Logins icon. Click this icon to access the Add login option. After you open this option, type the user name and password for the new login, as well as which databases the login is allowed to access. You must grant the test account access to the database you specify in the EAV configuration.
Figure A.14 shows the settings and default values of a MySQL-type monitor.
Name ""
Type mysql
Alias Address * All Addresses
Alias Service Port * All Ports
Name
Specifies a unique name for the custom monitor, such as my_mysql_monitor.
Type
Specifies the type of monitor you are creating.
Interval
Specifies the frequency at which the system issues the monitor check. The default is 30 seconds.
Timeout
Specifies the number of seconds in which the node must respond to the monitor request. The default is 91 seconds. If the node responds within the set time period, the node is considered to be up. If the node does not respond within the set time period, the node is considered to be down. The Timeout value should be three times the Interval value, plus one second.
Manual Resume
Using the Manual Resume setting, you can manually designate a resource as being available. For more information, see Chapter 13, Configuring Monitors.
Time Until Up
Delays the marking of a pool member or node as up for some number of seconds after receiving the first correct response. When this attribute is set to 0 (the default value), the BIG-IP system marks the resource as up immediately after receiving the first correct response. For more information, see Chapter 13, Configuring Monitors.
Send String
The Send String setting is optional and specifies a SQL query statement that the BIG-IP system should send to the server. Examples are SELECT * FROM sales and SELECT FirstName, LastName From Employees. If you configure the Send String setting, you can also configure the Receive String, Receive Row, and Receive Column settings.
Receive String
The Receive String setting is an optional parameter that specifies the value expected to be returned for the row and column specified with the Receive Row and Receive Column settings. An example of a Receive String value is ALAN SMITH. You can only configure this setting when you configure the Send String setting.
Database
The Database setting specifies the name of the data source on the SQL-based server. Examples are sales and hr.
Receive Row
The Receive Row setting is optional, and is useful only if the Receive String setting is specified. This setting specifies the row in the returned table that contains the Receive String value. You can only configure this setting when you configure the Send String and Receive String settings.
Receive Column
The Receive Column setting is optional and is useful only if the Receive String setting is specified. This setting specifies the column in the returned table that contains the Receive String value. You can configure this setting only when you configure the Send String and Receive String settings.
Count
The Count setting specifies how the system handles open connections for monitor instances. The default is 0. By default, when you assign instances of this monitor to a resource, the system keeps the connection to the database open. For more information, see the BIG-IP Configuration utility online help.
Alias Address and Alias Service Port
The Alias Address setting specifies the destination IP address that the monitor checks, with the default value * All Addresses. For more information, see Chapter 13, Configuring Monitors.
Debug
The Debug setting specifies whether the monitor sends error messages and additional information to a log file created and labeled specifically for the monitor. Possible values for the Debug setting are No and Yes. The default setting is No, which specifies that the system does not redirect error messages and additional information related to this monitor. The Yes setting specifies that the system redirects error messages and additional information to the /var/log/<monitor_type>_<ip_address>.<port>.log file. You can use the log information to help diagnose and troubleshoot unsuccessful health checks.
You use an NNTP type of monitor to check the status of Usenet News traffic. The check is successful if the monitor retrieves a newsgroup identification line from the server. An NNTP monitor requires a newsgroup name (for example, alt.cars.mercedes) and, if necessary, a user name and password.
Figure A.16 shows the settings and default values of an NNTP-type monitor.
Name ""
Type NNTP
Alias Address * All Addresses
Alias Service Port * All Ports
Name
Specifies a unique name for the custom monitor, such as my_nntp_monitor.
Type
Specifies the type of monitor you are creating.
Interval
Specifies the frequency at which the system issues the monitor check. The default value, in seconds, is 5.
Timeout
Specifies the number of seconds in which the node must respond to the monitor request. The default value, in seconds, is 16. If the node responds within the set time period, the node is considered to be up. If the node does not respond within the set time period, the node is considered to be down. The Timeout value should be three times the Interval value, plus one second.
Manual Resume
Using the Manual Resume setting, you can manually designate a resource as being available. For more information, see Chapter 13, Configuring Monitors.
Time Until Up
Delays the marking of a pool member or node as up for some number of seconds after receiving the first correct response. When this attribute is set to 0 (the default value), the BIG-IP system marks the resource as up immediately after receiving the first correct response. For more information, see Chapter 13, Configuring Monitors.
Alias Address and Alias Service Port
The Alias Address setting specifies the destination IP address that the monitor checks, with the default value * All Addresses. For more information, see Chapter 13, Configuring Monitors.
Debug
The Debug setting specifies whether the monitor sends error messages and additional information to a log file created and labeled specifically for the monitor. Possible values for the Debug setting are No and Yes. The default value is No, which specifies that the system does not redirect error messages and additional information related to this monitor. The Yes value specifies that the system redirects error messages and additional information to the /var/log/<monitor_type>_<ip_address>.<port>.log file. You can use the log information to help diagnose and troubleshoot unsuccessful health checks.
With an Oracle type of monitor, you can check the status of an Oracle database server. The check is successful if the monitor is able to connect to the server, log in as the indicated user, and log out.
Figure A.17 shows the settings and default values of an Oracle-type monitor.
Name ""
Type Oracle
Alias Address * All Addresses
Alias Service Port * All Ports
Name
Specifies a unique name for the custom monitor, such as my_oracle_monitor.
Type
Specifies the type of monitor you are creating.
Interval
Specifies the frequency at which the system issues the monitor check. The default is 30 seconds.
Timeout
Specifies the number of seconds in which the node must respond to the monitor request. The default is 91 seconds. If the node responds within the set time period, the node is considered to be up. If the node does not respond within the set time period, the node is considered to be down. The Timeout value should be three times the Interval value, plus one second.
Manual Resume
Using the Manual Resume setting, you can manually designate a resource as being available. For more information, see Chapter 13, Configuring Monitors.
Time Until Up
Delays the marking of a pool member or node as up for some number of seconds after receiving the first correct response. When this attribute is set to 0 (the default value), the BIG-IP system marks the resource as up immediately after receiving the first correct response. For more information, see Chapter 13, Configuring Monitors.
Send String
The Send String setting specifies a SQL statement that the BIG-IP system should send to the Oracle server. An example is SELECT * FROM sales.
Receive String
The Receive String setting is an optional parameter that specifies the value expected to be returned for a specific row and column of the table that the Send String setting retrieved. An example of a Receive String value is SMITH.
Database
In an Oracle type of monitor, the Database setting specifies the name of the data source on the Oracle server. Examples are sales and hr.
Receive Row
The Receive Row setting is optional, and is useful only if the Receive String setting is specified. This setting specifies the row in the returned table that contains the Receive String value.
Receive Column
The Receive Column setting is optional and is useful only if the Receive String setting is specified. This setting specifies the column in the returned table that contains the Receive String value.
Count
The Count setting specifies how the system handles open connections for monitor instances. The default is 0. By default, when you assign instances of this monitor to a resource, the system keeps the connection to the database open. For more information, see the BIG-IP Configuration utility online help.
Alias Address and Alias Service Port
The Alias Address setting specifies the destination IP address that the monitor checks, with the default value * All Addresses. For more information, see Chapter 13, Configuring Monitors.
Debug
The Debug setting specifies whether the monitor sends error messages and additional information to a log file created and labeled specifically for the monitor. Possible values for the Debug setting are No and Yes. The default setting is No, which specifies that the system does not redirect error messages and additional information related to this monitor. The Yes setting specifies that the system redirects error messages and additional information to the /var/log/<monitor_type>_<ip_address>.<port>.log file. You can use the log information to help diagnose and troubleshoot unsuccessful health checks.
A POP3 type of monitor checks the status of Post Office Protocol (POP) traffic. The check is successful if the monitor is able to connect to the server, log in as the indicated user, and log out. A POP3 monitor requires a user name and password.
Figure A.18 shows the settings and default values of a POP3-type monitor
Name ""
Type POP3
Alias Address * All Addresses
Alias Service Port * All Ports
Name
Specifies a unique name for the custom monitor, such as my_pop3_monitor.
Type
Specifies the type of monitor you are creating.
Interval
Specifies the frequency at which the system issues the monitor check. The default is 5 seconds.
Timeout
Specifies the number of seconds in which the node must respond to the monitor request. The default is 16 seconds. If the node responds within the set time period, the node is considered to be up. If the node does not respond within the set time period, the node is considered to be down. The Timeout value should be three times the Interval value, plus one second.
Manual Resume
Using the Manual Resume setting, you can manually designate a resource as being available. For more information, see Chapter 13, Configuring Monitors.
Time Until Up
Delays the marking of a pool member or node as up for some number of seconds after receiving the first correct response. When this attribute is set to 0 (the default value), the BIG-IP system marks the resource as up immediately after receiving the first correct response. For more information, see Chapter 13, Configuring Monitors.
Alias Address and Alias Service Port
The Alias Address setting specifies the destination IP address that the monitor checks, with the default value * All Addresses. For more information, see Chapter 13, Configuring Monitors.
Debug
The Debug setting specifies whether the monitor sends error messages and additional information to a log file created and labeled specifically for the monitor. Possible values for the Debug setting are No and Yes. The default value is No, which specifies that the system does not redirect error messages and additional information related to this monitor. The Yes value specifies that the system redirects error messages and additional information to the /var/log/<monitor_type>_<ip_address>.<port>.log file. You can use the log information to help diagnose and troubleshoot unsuccessful health checks.
Figure A.14 shows the settings and default values of a PostgreSQL-type monitor.
Name ""
Type postgresql
Alias Address * All Addresses
Alias Service Port * All Ports
Name
Specifies a unique name for the custom monitor, such as my_mypostgresql_monitor.
Type
Specifies the type of monitor you are creating.
Interval
Specifies the frequency at which the system issues the monitor check. The default is 30 seconds.
Timeout
Specifies the number of seconds in which the node must respond to the monitor request. The default is 91 seconds. If the node responds within the set time period, the node is considered to be up. If the node does not respond within the set time period, the node is considered to be down. The Timeout value should be three times the Interval value, plus one second.
Manual Resume
Using the Manual Resume setting, you can manually designate a resource as being available. For more information, see Chapter 13, Configuring Monitors.
Time Until Up
Delays the marking of a pool member or node as up for some number of seconds after receiving the first correct response. When this attribute is set to 0 (the default value), the BIG-IP system marks the resource as up immediately after receiving the first correct response. For more information, see Chapter 13, Configuring Monitors.
Send String
The Send String setting is optional and specifies a SQL query statement that the BIG-IP system should send to the server. Examples are SELECT * FROM sales and SELECT FirstName, LastName From Employees. If you configure the Send String setting, you can also configure the Receive String, Receive Row, and Receive Column settings.
Receive String
The Receive String setting is an optional parameter that specifies the value expected to be returned for the row and column specified with the Receive Row and Receive Column settings. An example of a Receive String value is ALAN SMITH. You can only configure this setting when you configure the Send String setting.
Database
The Database setting specifies the name of the data source on the SQL-based server. Examples are sales and hr.
Receive Row
The Receive Row setting is optional, and is useful only if the Receive String setting is specified. This setting specifies the row in the returned table that contains the Receive String value. You can only configure this setting when you configure the Send String and Receive String settings.
Receive Column
The Receive Column setting is optional and is useful only if the Receive String setting is specified. This setting specifies the column in the returned table that contains the Receive String value. You can configure this setting only when you configure the Send String and Receive String settings.
Count
The Count setting specifies how the system handles open connections for monitor instances. The default is 0. By default, when you assign instances of this monitor to a resource, the system keeps the connection to the database open. For more information, see the BIG-IP Configuration utility online help.
Alias Address and Alias Service Port
The Alias Address setting specifies the destination IP address that the monitor checks, with the default value * All Addresses. For more information, see Chapter 13, Configuring Monitors.
Debug
The Debug setting specifies whether the monitor sends error messages and additional information to a log file created and labeled specifically for the monitor. Possible values for the Debug setting are No and Yes. The default setting is No, which specifies that the system does not redirect error messages and additional information related to this monitor. The Yes setting specifies that the system redirects error messages and additional information to the /var/log/<monitor_type>_<ip_address>.<port>.log file. You can use the log information to help diagnose and troubleshoot unsuccessful health checks.
Using a RADIUS type of monitor, you can check the status of Remote Access Dial-in User Service (RADIUS) servers. The check is successful if the server authenticates the requesting user. A RADIUS monitor requires a user name, a password, and a shared secret string for the code number.
Note: Servers to be checked by a RADIUS monitor typically require special configuration to maintain a high level of security while also allowing for monitor authentication.
Figure A.20 shows the settings and default values of a RADIUS-type monitor.
Type RADIUS
Alias Address * All Addresses
Name
Specifies a unique name for the custom monitor, such as my_radius_monitor.
Type
Specifies the type of monitor you are creating.
Interval
Specifies the frequency at which the system issues the monitor check. The default is 10 seconds.
Timeout
Specifies the number of seconds in which the node must respond to the monitor request. The default is 31 seconds. If the node responds within the set time period, the node is considered to be up. If the node does not respond within the set time period, the node is considered to be down. The Timeout value should be three times the Interval value, plus one second.
Manual Resume
Using the Manual Resume setting, you can manually designate a resource as being available. For more information, see Chapter 13, Configuring Monitors.
Time Until Up
Delays the marking of a pool member or node as up for some number of seconds after receiving the first correct response. When this attribute is set to 0 (the default value), the BIG-IP system marks the resource as up immediately after receiving the first correct response. For more information, see Chapter 13, Configuring Monitors.
User Name
The User Name setting specifies the user name for the system to use if the targeted server requires a user name for authentication.
Password
The Password setting specifies the password for the system to use if the targeted server requires a password for authentication.
Secret
The Secret setting specifies the RADIUS secret that the monitor requires to access the resource.
Alias Address and Alias Service Port
The Alias Address setting specifies the destination IP address that the monitor checks, with the default value * All Addresses. For more information, see Chapter 13, Configuring Monitors.
Debug
The Debug setting specifies whether the monitor sends error messages and additional information to a log file created and labeled specifically for the monitor. Possible values for the Debug setting are No and Yes. The default setting is No, which specifies that the system does not redirect error messages and additional information related to this monitor. The Yes setting specifies that the system redirects error messages and additional information to the /var/log/<monitor_type>_<ip_address>.<port>.log file. You can use the log information to help diagnose and troubleshoot unsuccessful health checks.
Using a RADIUS type of monitor, you can check the status of Remote Access Dial-in User Service (RADIUS) accounting servers. A RADIUS Accounting monitor requires a user name and a shared secret string for the code number.
Figure A.20 shows the settings and default values of a RADIUS Accounting-type monitor.
Type RADIUS Accounting
Alias Address * All Addresses
Name
Specifies a unique name for the custom monitor, such as my_radius_monitor.
Type
Specifies the type of monitor you are creating.
Interval
Specifies the frequency at which the system issues the monitor check. The default is 10 seconds.
Timeout
Specifies the number of seconds in which the node must respond to the monitor request. The default is 31 seconds. If the node responds within the set time period, the node is considered to be up. If the node does not respond within the set time period, the node is considered to be down. The Timeout value should be three times the Interval value, plus one second.
Manual Resume
Using the Manual Resume setting, you can manually designate a resource as being available. For more information, see Chapter 13, Configuring Monitors.
Time Until Up
Delays the marking of a pool member or node as up for some number of seconds after receiving the first correct response. When this attribute is set to 0 (the default value), the BIG-IP system marks the resource as up immediately after receiving the first correct response. For more information, see Chapter 13, Configuring Monitors.
User Name
The User Name setting specifies the user name for the system to use if the targeted server requires a user name for authentication.
Secret
The Secret setting specifies the RADIUS secret that the monitor requires to access the resource.
Alias Address and Alias Service Port
The Alias Address setting specifies the destination IP address that the monitor checks, with the default value * All Addresses. For more information, see Chapter 13, Configuring Monitors.
Debug
The Debug setting specifies whether the monitor sends error messages and additional information to a log file created and labeled specifically for the monitor. Possible values for the Debug setting are No and Yes. The default setting is No, which specifies that the system does not redirect error messages and additional information related to this monitor. The Yes setting specifies that the system redirects error messages and additional information to the /var/log/<monitor_type>_<ip_address>.<port>.log file. You can use the log information to help diagnose and troubleshoot unsuccessful health checks
Through the RPC monitor, you can use the BIG-IP system to check the availability of specific programs that reside on a Remote Procedure Call (RPC) server. This monitor uses the rpcinfo command to query the RPC server and verify the availability of a given program.
The RPC monitor contains two unique settings: program and version. The program setting specifies the program or application which the monitor needs to verify is available. The version setting is an optional setting that specifies an exact version number of that program. If you do not specify a version number, the monitor uses the rpcinfo command to verify that at least one version of the program is available. In addition, you can use the mode option of the RPC monitor to verify the availability of an RPC server using either TCP or UDP.
The resource that this monitor checks is considered available if it responds with a ready and waiting statement to the monitor query.
Figure A.22 shows the settings and default values of an RPC-type monitor.
Name ""
Type RPC
Mode TCP
Program <name>
Alias Address * All Addresses
Alias Service Port * All Ports
Name
Specifies a unique name for the custom monitor, such as my_rpc_monitor.
Type
Specifies the type of monitor you are creating.
Interval
Specifies the frequency at which the system issues the monitor check. The default is 10 seconds.
Timeout
Specifies the number of seconds in which the node must respond to the monitor request. The default is 31 seconds. If the node responds within the set time period, the node is considered to be up. If the node does not respond within the set time period, the node is considered to be down. The Timeout value should be three times the Interval value, plus one second.
Manual Resume
Using the Manual Resume setting, you can manually designate a resource as being available. For more information, see Chapter 13, Configuring Monitors.
Time Until Up
Delays the marking of a pool member or node as up for some number of seconds after receiving the first correct response. When this attribute is set to 0 (the default value), the BIG-IP system marks the resource as up immediately after receiving the first correct response. For more information, see Chapter 13, Configuring Monitors.
Mode
You can use the Mode option of the RPC monitor to verify the availability of an RPC server using either TCP or UDP.
Program
The Program setting specifies the program or application which the monitor needs to verify is available.
Version Number
The Version Number setting is an optional setting that specifies an exact version number of that program. If you do not specify a version number, the monitor uses the rpcinfo command to verify that at least one version of the program is available.
Alias Address and Alias Service Port
The Alias Address setting specifies the destination IP address that the monitor checks, with the default value * All Addresses. For more information, see Chapter 13, Configuring Monitors.
The Debug setting specifies whether the monitor sends error messages and additional information to a log file created and labeled specifically for the monitor. Possible values for the Debug setting are No and Yes. The default value is No, which specifies that the system does not redirect error messages and additional information related to this monitor. The Yes value specifies that the system redirects error messages and additional information to the /var/log/<monitor_type>_<ip_address>.<port>.log file. You can use the log information to help diagnose and troubleshoot unsuccessful health checks.
A Real Server type of monitor checks the performance of a node that is running the RealSystem Server data collection agent. The monitor then dynamically load balances traffic accordingly. Performance monitors are generally used with dynamic ratio load balancing. For more information on performance monitors and dynamic ratio load balancing, see Chapter 4, Configuring Load Balancing Pools, and Appendix B, Configuring Dynamic Ratio Load Balancing.
The BIG-IP system provides a pre-configured Real Server monitor named real_server. Figure A.23 shows the settings and default values of the real_server monitor.
Figure A.23 The real_server pre-configured monitor
Type Real Server
Method GET
Command GetServerStats
Metrics ServerBandwidth:1.5, CPUPercentUsage, MemoryUsage, TotalClientCount
Agent Mozilla/4.0 (compatible: MSIE 5.0; Windows NT)
Like all pre-configured monitors, the real_server monitor cannot be modified by users. However, if you want to modify the Metrics setting, you can create a custom Real Server monitor, to which you can add metrics and modify metric values.
Name
Specifies a unique name for the custom monitor, such as my_real_server_monitor.
Type
Specifies the type of monitor you are creating.
Interval
Specifies the frequency at which the system issues the monitor check. The default is 5 seconds.
Timeout
Specifies the number of seconds in which the node must respond to the monitor request. The default is 16 seconds. If the node responds within the set time period, the node is considered to be up. If the node does not respond within the set time period, the node is considered to be down. The Timeout value should be three times the Interval value, plus one second.
Manual Resume
Using the Manual Resume setting, you can manually designate a resource as being available. For more information, see Chapter 13, Configuring Monitors.
Note: When creating a custom Real Server monitor, you cannot modify the values of the Method, Command, and Agent settings.
Table A.2 shows the complete set of server-specific metrics and metric setting default values that apply to the GetServerStats command.
The metric coefficient is a factor determining how heavily the metrics value counts in the overall ratio weight calculation. The metric threshold is the highest value allowed for the metric if the metric is to have any weight at all. To understand how to use these values, it is necessary to understand how the overall ratio weight is calculated. The overall ratio weight is the sum of relative weights calculated for each metric. The relative weights, in turn, are based on three factors:
You can see that the higher the coefficient, the greater the relative weight calculated for the metric. Similarly, the higher the threshold, the greater the relative weight calculated for any metric value that is less than the threshold. (When the value reaches the threshold, the weight goes to zero.)
Note that the default coefficient and default threshold values shown in Table A.2 are metric defaults, not monitor defaults. The monitor defaults take precedence over the metric defaults, just as user-specified values in the custom real_server monitor take precedence over the monitor defaults. For example, the monitor shown specifies a coefficient value of 1.5 for ServerBandwidth and no value for the other metrics. This means that the monitor uses the monitor default of 1.5 for the ServerBandwidth coefficient and the metric default of 1 for the coefficients of all other metrics. However, if a custom monitor my_real_server were configured specifying 2.0 as the ServerBandwidth coefficient, this user-specified value would override the monitor default.
Metric coefficient and threshold are the only non-monitor defaults. If a metric not in the monitor is to be added to the custom monitor, it must be added to the list of metrics for the Metrics setting. The syntax for specifying non-default coefficient or threshold values is:
If your network employs IBM® Group Workload Managers for some of your network resources, you can employ the SASP monitor to verify the availability of these resources. This monitor uses the Server/Application State Protocol (SASP) to communicate with the Group Workload Manager. The monitor queries the Group Workload Manager for information on the current weights of each managed resource. These weights determine which resource currently provides the best response time. When the monitor receives this information from the Group Workload Manager (GWM), it configures the dynamic ratio option for the resources, allowing the BIG-IP system to select the most appropriate resource to respond to a connection request.
Note: When you assign an SASP monitor, the monitor initially marks the resources as down. This change in status occurs because the GWM might not yet have information pertaining to its resources. As soon as the monitor receives the results of its query, it changes the status as needed. In most configurations, the monitor receives these results within a few seconds.
Figure A.24 shows the settings and default values of an SASP-type monitor.
Name ""
Type SASP
GWM Interval Automatic
GWM Address 10.10.5.23
Name
Specifies a unique name for the custom monitor, such as my_sasp_monitor.
Type
Specifies the type of monitor you are creating.
GWM Interval
The GWM Interval option determines the frequency at which the monitor queries the GWM. You can either set this option to Automatic, which instructs the monitor to use the interval GWM recommends; or you can select Specify, which allows you to supply an interval. If you select Specify, you can assign an interval between 10 and 600 seconds.
GWM Address
The GWM Address option specifies the IP address of the Group Workload Manager.
GWM Service Port
The GWM Service Port option specifies the port through which the SASP monitor communicates with the Group Workload Manager.
GWM Protocol.
The GWM Protocol option allows you to specify which protocol the monitor uses: either TCP or UDP.
You use the Scripted type of monitor to generate a simple script that reads a file that you create. The file contains send and expect strings to specify lines that you want to send or that you expect to receive. For example, Figure A.25 shows a sample file that you could create, which specifies a simple SMTP sequence. Note that the lines of the file are always read in the sequence specified.
Using a Scripted monitor, you can then generate a script that acts on the above file. When the Scripted monitor script reads this file, the script examines each line, and if the line has no quotation marks (" "), the line is sent or expected to be received as is. If the line is surrounded by quotation marks, the script strips off the quotation marks, and examines the line for escape characters, treating them accordingly.
Figure A.26 shows the settings and default values of a Scripted-type monitor.
Name ""
Type Scripted
Filename <filename>
Alias Address * All Addresses
Alias Service Port * All Ports
Name
Specifies a unique name for the custom monitor, such as my_scripted_monitor.
Type
Specifies the type of monitor you are creating.
Interval
Specifies the frequency at which the system issues the monitor check. The default is 10 seconds.
Timeout
Specifies the number of seconds in which the node must respond to the monitor request. The default is 31 seconds. If the node responds within the set time period, the node is considered to be up. If the node does not respond within the set time period, the node is considered to be down. The Timeout value should be three times the Interval value, plus one second.
Manual Resume
Using the Manual Resume setting, you can manually designate a resource as being available. For more information, see Chapter 13, Configuring Monitors.
Time Until Up
Delays the marking of a pool member or node as up for some number of seconds after receiving the first correct response. When this attribute is set to 0 (the default value), the BIG-IP system marks the resource as up immediately after receiving the first correct response. For more information, see Chapter 13, Configuring Monitors.
Filename
The Filename setting specifies the name of a file that you create. The file contains send and expect strings to specify lines that you want to send or that you expect to receive.
Alias Address and Alias Service Port
The Alias Address setting specifies the destination IP address that the monitor checks, with the default value * All Addresses. For more information, see Chapter 13, Configuring Monitors.
The Debug setting specifies whether the monitor sends error messages and additional information to a log file created and labeled specifically for the monitor. Possible values for the Debug setting are No and Yes. The default setting is No, which specifies that the system does not redirect error messages and additional information related to this monitor. The Yes setting specifies that the system redirects error messages and additional information to the /var/log/<monitor_type>_<ip_address>.<port>.log file. You can use the log information to help diagnose and troubleshoot unsuccessful health checks.
You use a SIP type of monitor to check the status of SIP Call-ID services. By default, this monitor type issues a SIP OPTIONS request to a server device. However, you can use alternative protocols instead: TCP, TLS, and SIPS (that is, Secure SIP).
The request that the monitor issues to a device is designed to identify the options that the server device supports. If the proper request is returned, the device is considered to be up and responding to commands.
Figure A.27 shows the settings and default values of a SIP-type monitor.
Name ""
Type SIP
Mode UDP
Cipher List DEFAULT:+SHA:+3DES:+kEDH
Alias Address * All Addresses
Alias Service Port * All Ports
Name
Specifies a unique name for the custom monitor, such as my_sip_monitor.
Type
Specifies the type of monitor you are creating.
Interval
Specifies the frequency at which the system issues the monitor check. The default is 5 seconds.
Timeout
Specifies the number of seconds in which the node must respond to the monitor request. The default is 16 seconds. If the node responds within the set time period, the node is considered to be up. If the node does not respond within the set time period, the node is considered to be down. The Timeout value should be three times the Interval value, plus one second.
Manual Resume
Using the Manual Resume setting, you can manually designate a resource as being available. For more information, see Chapter 13, Configuring Monitors.
Time Until Up
Delays the marking of a pool member or node as up for some number of seconds after receiving the first correct response. When this attribute is set to 0 (the default value), the BIG-IP system marks the resource as up immediately after receiving the first correct response. For more information, see Chapter 13, Configuring Monitors.
Mode
Possible values for the Mode setting are TCP , UDP, TLS, and SIPS.
Cipher List
For TLS and SIPS modes only, specifies the list of ciphers for this monitor.
Compatibility
For TLS and SIPS modes only, specifies, when enabled, that the SSL options setting (in OpenSSL) is set to ALL.
Client Certificate
For TLS and SIPS modes only, specifies a client certificate that the monitor sends to the target SSL server.
Client Key
For TLS and SIPS modes only, specifies a key for a client certificate that the monitor sends to the target SSL server.
Additional Accepted Status Codes
Possible values for the Additional Accepted Status Codes setting are Any, None, and Status Code List. By selecting Status Code List, you can specify one or more accepted status codes, in addition to status code 200, that the system treats differently. Multiple status codes should be separated by spaces. Specifying Any indicates that all status codes are to be used to mark a server as up. If this setting and the Additional Rejected Status Codes setting show the same value, the Additional Accepted Status Codes setting takes precedence.
Additional Rejected Status Codes
Possible values for the Additional Rejected Status Codes setting are Any, None, and Status Code List. By selecting Status Code List, you can specify one or more rejected status codes that the system treats differently. Multiple status codes should be separated by spaces. Specifying Any indicates that all status codes are to be used to mark a server as down. If this setting and the Additional Accepted Status Codes setting show the same value, the Additional Accepted Status Codes setting takes precedence.
Header List
Using the Header List setting, you can add, edit, or delete a header, but you cannot delete a default header the SIP monitor uses. Also, for certain headers, the only way to augment a default header, such as to add a parameter to it, is to override the entire header.
SIP Request
The SIP Request setting specifies the request line of the SIP message. Make sure to specify a complete SIP request line, minus the trailing \r\n characters. The system uses the response code to determine whether the server is up or down. The monitor performs a simple, customized query to a SIP server. The monitor does not establish connections, perform hand-shaking, or process SIP traffic or requests. It only sends a request to a server and looks at the response code and (aside from matching the response to the request) ignores the rest of the response. As a result, this monitor does not support requests such as INVITE, since the monitor does not enter into a dialog.
Alias Address and Alias Service Port
The Alias Address setting specifies the destination IP address that the monitor checks, with the default value * All Addresses. For more information, see Chapter 13, Configuring Monitors.
Debug
The Debug setting specifies whether the monitor sends error messages and additional information to a log file created and labeled specifically for the monitor. The default setting is No, which specifies that the system does not redirect error messages and additional information related to this monitor. The Yes setting specifies that the system redirects error messages and additional information to the /var/log/<monitor_type>_<ip_address>.<port>.log file. You can use the log information to help diagnose and troubleshoot unsuccessful health checks.
With the SMB monitor, you can use the BIG-IP system to verify the availability of an SMB/CIFS (Server Message Block/Common Internet File System) server. You can employ this monitor to either check the availability of the server as a whole, the availability of a specific service on the server, or the availability of a specific file used by a service.
If you only specify the server using the SMB/CIFS Server setting, leaving the Service Name and Path/Filename settings empty, the monitor attempts to retrieve a list of available services from the SMB/CIFS server. If the monitor acquires a list, it marks the server as available.
Figure A.28 shows the settings and default values of a SMB-type monitor.
Name ""
Type SMB
User Name <name>
Password <password>
Path/Filename <filename and path>
Alias Address * All Addresses
Alias Service Port * All Ports
Name
Specifies a unique name for the custom monitor, such as my_smb_monitor.
Type
Specifies the type of monitor you are creating.
Interval
Specifies the frequency at which the system issues the monitor check. The default is 10 seconds.
Timeout
Specifies the number of seconds in which the node must respond to the monitor request. The default is 31 seconds. If the node responds within the set time period, the node is considered to be up. If the node does not respond within the set time period, the node is considered to be down. The Timeout value should be three times the Interval value, plus one second.
Manual Resume
Using the Manual Resume setting, you can manually designate a resource as being available. For more information, see Chapter 13, Configuring Monitors.
Time Until Up
Delays the marking of a pool member or node as up for some number of seconds after receiving the first correct response. When this attribute is set to 0 (the default value), the BIG-IP system marks the resource as up immediately after receiving the first correct response. For more information, see Chapter 13, Configuring Monitors.
Path/Filename
Specifies a specific file associated with a service. The monitor uses the relative path to the service itself when attempting to locate the file. You are not required to specify a value for this option; however, if you elect to use this option, you must also specify a service using the Service Name setting.
SMB/CIFS Server
Specifies the NetBIOS name of the SMB/CIFS server for which the monitor checks for availability. You must specify a server for this monitor to function.
Service Name
Specifies a specific service on the SMB/CIFS for which you want to verify availability. You are not required to specify a service name.
Alias Address and Alias Service Port
The Alias Address setting specifies the destination IP address that the monitor checks, with the default value * All Addresses. For more information, see Chapter 13, Configuring Monitors.
Debug
Specifies whether the monitor sends error messages and additional information to a log file created and labeled specifically for the monitor. Possible values for the Debug setting are No and Yes. The default setting is No, which specifies that the system does not redirect error messages and additional information related to this monitor. The Yes setting specifies that the system redirects error messages and additional information to the /var/log/<monitor_type>_<ip_address>.<port>.log file. You can use the log information to help diagnose and troubleshoot unsuccessful health checks.
An SMTP type of monitor checks the status of Simple Mail Transport Protocol (SMTP) servers. This monitor type is an extremely basic monitor that checks only that the server is up and responding to commands. The check is successful if the mail server responds to the standard SMTP HELO and QUIT commands.
Figure A.29 shows the settings and default values of an SMTP-type monitor.
Name ""
Type SMTP
Alias Address * All Addresses
Alias Service Port * All Ports
Name
Specifies a unique name for the custom monitor, such as my_smtp_monitor.
Type
Specifies the type of monitor you are creating.
Interval
Specifies the frequency at which the system issues the monitor check. The default is 5 seconds.
Timeout
Specifies the number of seconds in which the node must respond to the monitor request. The default is 16 seconds. If the node responds within the set time period, the node is considered to be up. If the node does not respond within the set time period, the node is considered to be down. The Timeout value should be three times the Interval value, plus one second.
Manual Resume
Using the Manual Resume setting, you can manually designate a resource as being available. For more information, see Chapter 13, Configuring Monitors.
Time Until Up
Delays the marking of a pool member or node as up for some number of seconds after receiving the first correct response. When this attribute is set to 0 (the default value), the BIG-IP system marks the resource as up immediately after receiving the first correct response. For more information, see Chapter 13, Configuring Monitors.
Domain
An SMTP-type monitor requires a domain name.
Alias Address and Alias Service Port
The Alias Address setting specifies the destination IP address that the monitor checks, with the default value * All Addresses. For more information, see Chapter 13, Configuring Monitors.
Debug
The Debug setting specifies whether the monitor sends error messages and additional information to a log file created and labeled specifically for the monitor. Possible values for the Debug setting are No and Yes. The default setting is No, which specifies that the system does not redirect error messages and additional information related to this monitor. The Yes setting specifies that the system redirects error messages and additional information to the /var/log/<monitor_type>_<ip_address>.<port>.log file. You can use the log information to help diagnose and troubleshoot unsuccessful health checks.
With an SNMP DCA type of monitor, you can check the performance of a server running an SNMP agent such as UC Davis, for the purpose of load balancing traffic to that server. With this monitor you can define ratio weights for CPU, memory, and disk use.
Performance monitors are generally used with dynamic ratio load balancing. For more information on performance monitors and dynamic ratio load balancing, see Appendix B, Configuring Dynamic Ratio Load Balancing.
The BIG-IP system provides a pre-configured SNMP DCA monitor named snmp_dca. Figure A.30 shows the settings and values of the snmp_dca pre-configured monitor.
Figure A.30 The snmp_dca pre-configured monitor
Type SNMP DCA
Community Public
Pre-configured monitors are not user-modifiable. Thus, if you want to change the values for the SNMP DCA monitor settings, you must create an SNMP DCA-type custom monitor.
Possible values for the Version setting are v1, v2c, and Other.
The Agent Type setting identifies the group of SNMP objects that the BIG-IP system uses to determine server health. Possible values for the Agent Type setting are:
UCD
This agent type corresponds to the UCD MIB. The group of objects based on the UCD MIB provides CPU load that is averaged over the up time of the server.
WIN2000
This agent type is based on RFC 2790, the Host Resources MIB. The group of objects based on the Host Resources MIB provides CPU load that is averaged over one minute instead of over the up time of the server. This agent type works well for all server platforms and is therefore the recommended agent type.
Other
This is an agent type that you specify.
Table A.3 shows the SNMP objects corresponding to the UCD and WIN2000 agent types.
When configuring an SNMP DCA custom monitor, you can use the default CPU, memory, and disk coefficient and threshold values specified in the monitors, or you can change the default values. Optionally, you can specify coefficient and threshold values for gathering other types of data. Note that if the monitor you are configuring is for a type of SNMP agent other than UC Davis, you must specify the agent type, such as Win2000.
To understand how to use the coefficient and threshold values, it is necessary to understand how the overall ratio weight is calculated. The overall ratio weight is the sum of relative weights calculated for each metric. The relative weights, in turn, are based on three factors:
You can see that the higher the coefficient, the greater the relative weight calculated for the metric. Similarly, the higher the threshold, the greater the relative weight calculated for any metric value that is less than the threshold. (When the value reaches the threshold, the weight goes to zero.)
You use an SNMP DCA Base type of monitor to check the performance of servers that are running an SNMP agent, such as UC Davis. However, you should use this monitor only when you want the load balancing destination to be based solely on user data, and not CPU, memory or disk use.
Figure A.31 shows the settings and default values of an SNMP DCA Base type of monitor.
Figure A.31 An SNMP DCA-type custom monitor with default values
Name ""
Type snmp_dca_base
Community Public
Performance monitors are generally used with dynamic ratio load balancing. For more information on performance monitors and dynamic ratio load balancing, see Appendix B, Configuring Dynamic Ratio Load Balancing.
A SOAP monitor tests a Web service based on the Simple Object Access protocol (SOAP). More specifically, the monitor submits a request to a SOAP-based Web service, and optionally, verifies a return value or fault. Figure A.32 shows the settings and default values of a SOAP-type monitor.
Name ""
Type soap
Alias Address * All Addresses
Alias Service Port * All Ports
Name
Specifies a unique name for the custom monitor, such as my_soap_monitor.
Type
Specifies the type of monitor you are creating.
Interval
Specifies the frequency at which the system issues the monitor check. The default is 5 seconds.
Timeout
Specifies the number of seconds in which the node must respond to the monitor request. The default is 16 seconds. If the node responds within the set time period, the node is considered to be up. If the node does not respond within the set time period, the node is considered to be down. Also, if the target responds with a RESET packet, the system flags the target as down immediately, without waiting for the timeout interval to expire. The Timeout value should be three times the Interval value, plus one second.
Manual Resume
Using the Manual Resume setting, you can manually designate a resource as being available. For more information, see Chapter 13, Configuring Monitors.
Time Until Up
Delays the marking of a pool member or node as up for some number of seconds after receiving the first correct response. When this attribute is set to 0 (the default value), the BIG-IP system marks the resource as up immediately after receiving the first correct response. For more information, see Chapter 13, Configuring Monitors.
User Name
This setting specifies the user name, if the monitored target requires authentication.
Password
This setting specifies the password, if the monitored target requires authentication.
Protocol
This setting specifies the protocol that the monitor uses for communications with the target. Possible values for the Protocol setting are HTTP and HTTPS:
HTTP: Specifies that the monitor communicates with the target using HTTP. This is the default value.
HTTPS: Specifies that the monitor communicates with the target using HTTPS.
URL Path
This setting specifies the URL for the web service that you are monitoring, for example, /services/myservice.aspx.
Namespace
This setting specifies the name space for the web service you are monitoring, for example, http://example.com/.
Method
This setting displays the GET method. You cannot modify the method.
Parameter Name
This setting specifies, if the method has parameters, the parameter name.
Parameter Type
This setting specifies the parameter type. Possible values for the Parameter Type setting are: bool, int, long, and string.
ParameterValue
This setting specifies the value of the parameter.
Return Type
This setting specifies the type of the returned parameter. Possible values for the Return Type setting are: bool, int, short, long, float, double, and string.
Return Value
Specifies the value of the returned parameter.
Expect Fault
Possible values for the Expect Fault setting are No and Yes.
Alias Address and Alias Service Port
The Alias Address setting specifies the destination IP address that the monitor checks, with the default value * All Addresses. For more information, see Chapter 13, Configuring Monitors.
Debug
The Debug setting specifies whether the monitor sends error messages and additional information to a log file created and labeled specifically for the monitor. Possible values for the Debug setting are No and Yes. The default setting is No, which specifies that the system does not redirect error messages and additional information related to this monitor. The Yes setting specifies that the system redirects error messages and additional information to the /var/log/<monitor_type>_<ip_address>.<port>.log file. You can use the log information to help diagnose and troubleshoot unsuccessful health checks.
A TCP type of monitor attempts to receive specific content sent over TCP. The check is successful when the content matches the Receive String value. Figure A.33 shows the settings for the pre-configured monitor tcp.
Figure A.33 The tcp pre-configured monitor
Name ""
Type TCP
Alias Address * All Addresses
Alias Service Port * All Ports
Name
Specifies a unique name for the custom monitor, such as my_tcp_monitor.
Type
Specifies the type of monitor you are creating.
Interval
Specifies the frequency at which the system issues the monitor check. The default is 5 seconds.
Timeout
Specifies the number of seconds in which the node must respond to the monitor request. The default is 16 seconds. If the node responds within the set time period, the node is considered to be up. If the node does not respond within the set time period, the node is considered to be down. The Timeout value should be three times the Interval value, plus one second.
Manual Resume
Using the Manual Resume setting, you can manually designate a resource as being available. For more information, see Chapter 13, Configuring Monitors.
Time Until Up
Delays the marking of a pool member or node as up for some number of seconds after receiving the first correct response. When this attribute is set to 0 (the default value), the BIG-IP system marks the resource as up immediately after receiving the first correct response. For more information, see Chapter 13, Configuring Monitors.
Send String and Receive String
This type of monitor takes a Send String value and a Receive String value. If the Send String value is blank and a connection can be made, the service is considered up. A blank Receive String value matches any response. The check is successful when the content matches the Receive String value.
Transparent and Reverse
Both Transparent and Reverse modes are options. For more information about Transparent and Reverse modes, see Chapter 13, Configuring Monitors.
Alias Address and Alias Service Port
The Alias Address setting specifies the destination IP address that the monitor checks, with the default value * All Addresses. For more information, see Chapter 13, Configuring Monitors.
With a TCP Echo type of monitor, you can verify Transmission Control Protocol (TCP) connections. The check is successful if the BIG-IP system receives a response to a TCP Echo message.
To use a TCP Echo monitor type, you must ensure that TCP Echo is enabled on the nodes being monitored. Figure A.34 shows the settings for the pre-configured monitor tcp_echo.
Figure A.34 The tcp_echo pre-configured monitor
Name ""
Type TCP Echo
Alias Address * All Addresses
Name
Specifies a unique name for the custom monitor, such as my_tcp_echo_monitor.
Type
Specifies the type of monitor you are creating.
Interval
Specifies the frequency at which the system issues the monitor check. The default is 5 seconds.
Timeout
Specifies the number of seconds in which the node must respond to the monitor request. The default is 16 seconds. If the node responds within the set time period, the node is considered to be up. If the node does not respond within the set time period, the node is considered to be down. The Timeout value should be three times the Interval value, plus one second.
Manual Resume
Using the Manual Resume setting, you can manually designate a resource as being available. For more information, see Chapter 13, Configuring Monitors.
Time Until Up
Delays the marking of a node as up for some number of seconds after receiving the first correct response. When this attribute is set to 0 (the default value), the BIG-IP system marks the resource as up immediately after receiving the first correct response. For more information, see Chapter 13, Configuring Monitors.
Transparent
The Transparent mode is an option for this type of monitor. When you set this mode to Yes, the monitor pings the node with which the monitor is associated. For more information about Transparent mode, see Chapter 13, Configuring Monitors.
Alias Address and Alias Service Port
The Alias Address setting specifies the destination IP address that the monitor checks, with the default value * All Addresses. For more information, see Chapter 13, Configuring Monitors.
A TCP Half Open type of monitor performs a quick check on the associated service by sending a TCP SYN packet to the service. As soon as the monitor receives the SYN-ACK packet from the service, the monitor considers the service to be in an up state, and sends a RESET to the service instead of completing the three-way handshake.
Figure A.35 shows the settings for the pre-configured monitor tcp_half_open.
Figure A.35 The tcp_half_open pre-configured monitor
Name ""
Type TCP Half Open
Alias Addresses * All Addresses
Alias Service Port * All Ports
Name
Specifies a unique name for the custom monitor, such as my_tcp_half_open_monitor.
Type
Specifies the type of monitor you are creating.
Interval
Specifies the frequency at which the system issues the monitor check. The default is 5 seconds.
Timeout
Specifies the number of seconds in which the node must respond to the monitor request. The default is 16 seconds. If the node responds within the set time period, the node is considered to be up. If the node does not respond within the set time period, the node is considered to be down. The Timeout value should be three times the Interval value, plus one second.
Manual Resume
Using the Manual Resume setting, you can manually designate a resource as being available. For more information, see Chapter 13, Configuring Monitors.
Time Until Up
Delays the marking of a pool member or node as up for some number of seconds after receiving the first correct response. When this attribute is set to 0 (the default value), the BIG-IP system marks the resource as up immediately after receiving the first correct response. For more information, see Chapter 13, Configuring Monitors.
Transparent
The Transparent mode is an option for this type of monitor. When you set this mode to Yes, the monitor pings the node with which the monitor is associated. For more information about Transparent mode, see Chapter 13, Configuring Monitors.
Alias Address and Alias Service Port
The Alias Address setting specifies the destination IP address that the monitor checks, with the default value * All Addresses. For more information, see Chapter 13, Configuring Monitors.
You use a UDP type of monitor when the system is sending User Datagram Protocol (UDP) packets. Designed to check the status of a UDP service, a UDP-type monitor sends one or more UDP packets to a target pool, pool member, or node.
Figure A.36 shows the settings and default values of a UDP-type monitor.
Name ""
Send String default send string
Alias Address * All Addresses
Alias Service Port * All Ports
Name
Specifies a unique name for the custom monitor, such as my_udp_monitor.
Type
Specifies the type of monitor you are creating.
Interval
Specifies the frequency at which the system issues the monitor check. The default is 5 seconds.
Timeout
Specifies the number of seconds in which the node must respond to the monitor request. The default is 16 seconds. If the node responds within the set time period, the node is considered to be up. If the node does not respond within the set time period, the node is considered to be down. The Timeout value should be three times the Interval value, plus one second.
Manual Resume
Using the Manual Resume setting, you can manually designate a resource as being available. For more information, see Chapter 13, Configuring Monitors.
Time Until Up
Delays the marking of a pool member or node as up for some number of seconds after receiving the first correct response. When this attribute is set to 0 (the default value), the BIG-IP system marks the resource as up immediately after receiving the first correct response. For more information, see Chapter 13, Configuring Monitors.
Timeout Packets
The value in seconds of the Timeout Packets setting should be lower than the value of the Interval setting.
Debug
The Debug setting specifies whether the monitor sends error messages and additional information to a log file created and labeled specifically for the monitor. Possible values for the Debug setting are No and Yes. The default setting is No, which specifies that the system does not redirect error messages and additional information related to this monitor. The Yes setting specifies that the system redirects error messages and additional information to the /var/log/<monitor_type>_<ip_address>.<port>.log file. You can use the log information to help diagnose and troubleshoot unsuccessful health checks.
When using a UDP-type monitor to monitor a pool, pool member, or node, you must also enable another monitor type, such as ICMP, to monitor the pool, pool member, or node. Until both a UDP-type monitor and another type of monitor to report the status of the UDP service as up, the UDP service receives no traffic. See Table A.4 for details.
And another monitor reports status as
You use a WAP monitor to monitor Wireless Application Protocol (WAP) servers. The common usage for the WAP monitor is to specify the Send String and Receive String settings only. The WAP monitor functions by requesting a URL and finding the string in the Receive String setting somewhere in the data returned by the URL response. Figure A.37 shows the settings and default values of a WAP-type monitor.
Name ""
Alias Address * All Addresses
Alias Service Port * All Ports
Name
Specifies a unique name for the custom monitor, such as my_wap_monitor.
Type
Specifies the type of monitor you are creating.
Interval
Specifies the frequency at which the system issues the monitor check. The default is 10 seconds.
Timeout
Specifies the number of seconds in which the node must respond to the monitor request. The default is 31 seconds. If the node responds within the set time period, the node is considered to be up. If the node does not respond within the set time period, the node is considered to be down. The Timeout value should be three times the Interval value, plus one second.
Manual Resume
Using the Manual Resume setting, you can manually designate a resource as being available. For more information, see Chapter 13, Configuring Monitors.
Time Until Up
Delays the marking of a pool member or node as up for some number of seconds after receiving the first correct response. When this attribute is set to 0 (the default value), the BIG-IP system marks the resource as up immediately after receiving the first correct response. For more information, see Chapter 13, Configuring Monitors.
Send String
The Send String setting specifies a URL.
Receive String
The Receive String setting specifies the string that the monitor should find, somewhere in the data returned by the URL response.
Secret
The Secret setting is the RADIUS secret, a string known to both the client and the RADIUS server, and is used in computing the MD5 hash.
Accounting Node
The Accounting Node setting specifies the RADIUS node. If this is a null string and RADIUS accounting has been requested (accounting port is non-zero), then the WAP server node is assumed to also be the RADIUS node.
Accounting Port
The Accounting Port setting implements RADIUS accounting, which is optional. To implement RADIUS accounting, you must set the accounting port to a non-zero value. In this case, the monitor assumes that RADIUS accounting is needed, and an accounting request is sent to the specified accounting node and port to start accounting. This is done before the URL is requested. After the successful retrieval of the URL with the correct data, an accounting request is sent to stop accounting.
Server ID
The Server ID setting specifies the RADIUS NAS-ID of the requesting server (that is, the BIG-IP system). It is a string used as an alias for the FQDN.
Call ID
The Call ID setting is an identifier similar to a telephone number, that is, a string of numeric characters. For testing purposes, this value is usually a string of eleven characters.
Session ID
The Session ID setting is a RADIUS session ID, used to identify this session. This is an arbitrary numeric character string, often something like 01234567.
Framed Address
The Framed Address setting is a RADIUS framed IP address. The setting has no special use and is usually specified simply as 1.1.1.1.
Debug
The Debug setting specifies whether the monitor sends error messages and additional information to a log file created and labeled specifically for the monitor. Possible values for the Debug setting are No and Yes. The default setting is No, which specifies that the system does not redirect error messages and additional information related to this monitor. The Yes setting specifies that the system redirects error messages and additional information to the /var/log/<monitor_type>_<ip_address>.<port>.log file. You can use the log information to help diagnose and troubleshoot unsuccessful health checks.
A WMI type of monitor checks the performance of a node that is running the Windows Management Infrastructure (WMI) data collection agent, and then dynamically load balances traffic accordingly.
You generally use performance monitors such as a WMI monitor with dynamic ratio load balancing. For more information on performance monitors and dynamic ratio load balancing, see Appendix B, Configuring Dynamic Ratio Load Balancing.
Figure A.38 shows the settings and default values of a WMI-type monitor.
Name ""
Type wmi
Method POST
URL /scripts/f5Isapi.dll
Command GetCPUInfo, GetDiskInfo, GetOSInfo
Metrics LoadPercentage, DiskUsage, PhysicalMemoryUsage:1.5, VirtualMemoryUsage:2.0
Agent Mozilla/4.0 (compatible: MSIE 5.0; Windows NT)
Post RespFormat=HTML
Note that when creating a custom WMI monitor, the only default values that you are required to change are the null values for name, user name, and password. Also note that you cannot change the value of the Method setting.
Name
Specifies a unique name for the custom monitor, such as my_wmi_monitor.
Type
Specifies the type of monitor you are creating.
Interval
Specifies the frequency at which the system issues the monitor check. The default is 5 seconds.
Timeout
Specifies the number of seconds in which the node must respond to the monitor request. The default is 16 seconds. If the node responds within the set time period, the node is considered to be up. If the node does not respond within the set time period, the node is considered to be down. The Timeout value should be three times the Interval value, plus one second.
User Name and Password
This user name and password must match the user name and password for the user account that accesses WMI metrics on the Windows IIS server. If there is no password security, you must use blank strings [""] for the Username and Password settings.
Command and Metrics
See the following table.
Table A.5 shows the complete set of commands and metrics that you can specify with the Command and Metrics settings. Also shown are the default metric values.
Default Coefficient
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