Manual Chapter : Managing Local Traffic Monitors

Applies To:

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BIG-IQ Centralized Management

  • 5.3.0
Manual Chapter

How do I change object settings on a managed device?

To change the object settings on a managed device, there are four tasks to perform.

This figure illustrates the workflow you perform to manage the objects on BIG-IP® devices. Changing the settings is the second step in this process.

Workflow for changing object settings on a managed device

Change managed object workflow

What LTM monitor management tasks can I perform?

With HTTP and HTTPS monitors you can track the availability of these services on the nodes, pools, or pool members to which you attach them. To add or edit monitors, you need to log in as an Administrator or ADC Editor.

Note: You can revise the custom monitors, but you cannot edit the root monitors that ship with the product.

Create an LTM monitor

You add a new HTTP or HTTPS LTM® monitor so that you can track the availability of these services on the nodes, pools, or pool members to which you attach that monitor.
  1. At the top of the screen, click Configuration.
  2. Under LOCAL TRAFFIC, select Monitors.
  3. Click Create.
    The New Monitor screen opens.
  4. In the Name field, type in a name for the monitor you are creating.
  5. For Partition, type the name of the BIG-IP® device partition on which you want to create the monitor.
  6. In the Description field, type in a brief description for the monitor you are creating.
  7. For Type, select the type of monitor you want to create.
    The Monitor Template setting displays.
  8. From Monitor Template, select the parent monitor from which you want your monitor to inherit settings.
    A number of additional fields display. The fields that display depend on which monitor template you choose, HTTP or HTTPS.
  9. For Interval, either use the default, or specify, in seconds, the frequency at which the system issues the monitor check when either the resource is down or the status of the resource is unknown.
  10. From Up Interval, specify which interval the system uses to perform the health check when a resource is up.
    Option Description
    Disabled Specifies that the system uses the interval specified in Interval to check the health of the resource.
    Enabled Enables specification of a different interval to use when checking the health of a resource that is up.
  11. For Time Until Up, specify the number of seconds to wait after a resource first responds correctly to the monitor before setting the resource to up.
    During the interval, all responses from the resource must be correct. When the interval expires, the resource is marked up. The default is 0, meaning that the resource is marked up immediately when the first correct response is received.
  12. For Timeout, specify the number of seconds the target has in which to respond to the monitor request.
    The default is 16 seconds. If the target responds within the set time period, it is considered up. If the target does not respond within the set time period, it is considered down. Note that Timeout and Time Until Up combine to control when a resource is set to up.
  13. For Manual Resume, specify whether the system automatically changes the status of a resource to Enabled at the next successful monitor check.
    If you set this option to Yes, you must manually re-enable the resource before the system can use it for load balancing connections. The default is No.
  14. For Send String, specify the text string that the monitor sends to the target object.
    You must include \r\n at the end of a non-empty Send String. The default setting is GET /\r\n, which retrieves a default HTML file for a web site. To retrieve a specific page from a web site, specify a fully-qualified path name, for example:
                               
    GET /www/siterequest/index.html\r\n
                            
    
  15. For Receive String, specify a regular expression to represent the text string that the monitor looks for in the returned resource.
    The most common receive expressions contain a text string that is included in an HTML file on your site. The text string can be regular text, HTML tags, or image names.
    Note: If you do not specify both a Send String and a Receive String, the monitor performs a simple service check and connect only.
  16. For Receive Disable String, specify a regular expression to represent the text string that the monitor looks for in the returned resource.
    This setting works like Receive String, except that the system marks the node or pool member disabled when its response matches Receive Disable String.
    Note: To use this setting, you must specify both Receive String and Receive Disable String.
  17. If you selected HTTPS, for Cipher List, specify the list of ciphers for this monitor.
    The default list is DEFAULT:+SHA:+3DES:+kEDH.
  18. If the monitored target requires authentication, for the User Name, specify the user name.
  19. If the monitored target requires authentication, for the Password, specify the password.
  20. If you selected HTTPS, for Compatibility, specify the SSL option setting.
    If you select Enabled, the SSL option (in OpenSSL) is set to ALL.
  21. If you selected HTTPS, for Client Certificate, select the client certificate that the monitor sends to the target SSL server.
    The default is None.
  22. If you selected HTTPS, for Client Key, select the key for the client certificate that the monitor sends to the target SSL server.
    The default is None.
  23. For Reverse, specify whether the system marks the target resource down when the test is successful.
    This setting is useful, for example, if the content on your web site home page is dynamic and changes frequently. You might want to set up a reverse ECV service check that looks for the string Error. A match for this string means that the web server was down. To use this option, you must specify values for Send String and Receive String.
  24. For Transparent, specify whether the system operates in transparent mode.
    A monitor in transparent mode directs traffic through the associated pool members or nodes (usually a router or firewall) to the aliased destination (that is, it probes the Alias Address-Alias Service Port combination specified in the monitor). If the monitor cannot successfully reach the aliased destination, the pool member or node through which the monitor traffic was sent is marked down.
  25. For Alias Address, specify an alias IP address for the monitor to check, on behalf of the pools or pool members with which the monitor is associated.
    The default setting is *All Addresses. If the health check for the alias address is successful, the system marks all associated objects up. If the health check for the alias address is not successful, then the system marks all associated objects down.
  26. For Alias Service Port, specify an alias port or service for the monitor to check, on behalf of the pools or pool members with which the monitor is associated.
    The default setting is *All Ports. If the health check for the alias port or service is successful, the system marks all associated objects up. If the health check for the alias port or service is not successful, then the system marks all associated objects down.
  27. For IP DSCP, specify the differentiated services code point (DSCP).
    DSCP is a 6-bit value in the Differentiated Services (DS) field of the IP header. It can be used to specify the quality of service wanted for the packet. The valid range for this value is 0 to 63 (hex 0x0 to 0x3f). The default is 0 (zero).
  28. For Adaptive, specify whether adaptive response time monitoring is enabled for this monitor.
    Option Description
    Enabled The monitor determines the state of a service based on how divergent from the mean latency a monitor probe for that service is allowed to be. When enabled, you can set values for the Allowed Divergence, Adaptive Limit, and Sampling Timespan monitor settings.
    Disabled The monitor determines the state of a service based on the Interval, Up Interval, Time Until Up, and Timeout monitor settings.
    If you select Enabled for this control, three additional controls are displayed.
  29. If you enabled Adaptive, for Allowed Divergence, specify the type of divergence used for adaptive response time monitoring.
    Option Description
    Absolute The number of milliseconds the latency of a monitor probe can exceed the mean latency of a monitor probe for the service being probed. Tip: In typical cases, if the monitor detects three probes in a row that miss the latency value you set, the pool member or node is marked down.
    Relative The percentage of deviation the latency of a monitor probe can exceed the mean latency of a monitor probe for the service being probed.
  30. If you enabled Adaptive, for Allowed Divergence, specify the absolute number of milliseconds that may not be exceeded by a monitor probe, regardless of Allowed Divergence for a probe to be considered successful.
    This value applies regardless of the value of the Allowed Divergence setting.
  31. If you enabled Adaptive, for Sampling Timespan, specify the length, in seconds, of the probe history window that the system uses to calculate the mean latency and standard deviation of a monitor probe.

Edit an LTM monitor

You revise HTTP or HTTPS LTM® monitors when you want to change the details of how the monitor determines when a service is operational.
Note: You can not edit monitors root monitors.
  1. At the top of the screen, click Configuration.
  2. Under LOCAL TRAFFIC, select Monitors.
  3. Select the monitor you want to edit.
    The Monitors Properties screen opens to display the current settings for the selected monitor.
  4. In the Description field, if this is not an imported profile you can add or revise a brief description for the monitor you are editing.
  5. From Interval, specify, in seconds, the frequency at which the system issues the monitor check when either the resource is down or the status of the resource is unknown.
    The default is 5 seconds.
  6. For Up Interval, specify which interval the system uses to perform the health check when a resource is up.
    Option Description
    Disabled Specifies that the system uses the interval specified in Interval to check the health of the resource.
    Enabled Enables specification of a different interval to use when checking the health of a resource that is up.
  7. For Time Until Up, specify the number of seconds to wait after a resource first responds correctly to the monitor before setting the resource to up.
    During the interval, all responses from the resource must be correct. When the interval expires, the resource is marked up. The default is 0, meaning that the resource is marked up immediately when the first correct response is received.
  8. From Timeout, specify the number of seconds the target has in which to respond to the monitor request.
    The default is 16 seconds. If the target responds within the set time period, it is considered up. If the target does not respond within the set time period, it is considered down. Note that Timeout and Time Until Up combine to control when a resource is set to up.
  9. For Manual Resume, specify whether the system automatically changes the status of a resource to Enabled at the next successful monitor check.
    If you set this option to Yes, you must manually re-enable the resource before the system can use it for load balancing connections. The default is No.
  10. For Send String, specify the text string that the monitor sends to the target object.
    You must include \r\n at the end of a non-empty Send String. The default setting is GET /\r\n, which retrieves a default HTML file for a web site. To retrieve a specific page from a web site, specify a fully-qualified path name, for example:
                               
    GET /www/siterequest/index.html\r\n
                            
    
  11. For Receive String, specify a regular expression to represent the text string that the monitor looks for in the returned resource.
    The most common receive expressions contain a text string that is included in an HTML file on your site. The text string can be regular text, HTML tags, or image names.
    Note: If you do not specify both a Send String and a Receive String, the monitor performs a simple service check and connect only.
  12. For Receive Disable String, specify a regular expression to represent the text string that the monitor looks for in the returned resource.
    This setting works like Receive String, except that the system marks the node or pool member disabled when its response matches Receive Disable String.
    Note: To use this setting, you must specify both Receive String and Receive Disable String.
  13. If you selected HTTPS, for Cipher List, specify the list of ciphers for this monitor.
    The default list is DEFAULT:+SHA:+3DES:+kEDH.
  14. If the monitored target requires authentication, for the User Name, specify the user name.
  15. If the monitored target requires authentication, for the Password, specify the password.
    Important: For imported monitors that use passwords:
    • If the monitor was imported from a version 12.0.0 or later device, you do not need to re-enter the password.
    • If the monitor was imported from a device earlier than version 12.0.0 and you plan to make changes to the monitor (or if you associate the monitor with an LTM object or child monitor), then you must supply the password for the imported monitor.
    • If you do not change any of the parameters for the monitor or associate the monitor with an LTM object or child monitor, then you do not need to re-enter the password.
  16. If you selected HTTPS, for Compatibility specify the SSL option setting.
    If you select Enabled, the SSL option (in OpenSSL) is set to ALL.
  17. If you selected HTTPS, for Client Certificate, select the client certificate that the monitor sends to the target SSL server.
    The default is None.
  18. If you selected HTTPS, for Client Key, select the key for the client certificate that the monitor sends to the target SSL server.
    The default is None.
  19. For Reverse, specify whether the system marks the target resource down when the test is successful.
    This setting is useful, for example, if the content on your web site home page is dynamic and changes frequently. You might want to set up a reverse ECV service check that looks for the string Error. A match for this string means that the web server was down. To use this option, you must specify values for Send String and Receive String.
  20. For Transparent, specify whether the system operates in transparent mode.
    A monitor in transparent mode directs traffic through the associated pool members or nodes (usually a router or firewall) to the aliased destination (that is, it probes the Alias Address-Alias Service Port combination specified in the monitor). If the monitor cannot successfully reach the aliased destination, the pool member or node through which the monitor traffic was sent is marked down.
  21. For Alias Address, specify an alias IP address for the monitor to check, on behalf of the pools or pool members with which the monitor is associated.
    The default setting is *All Addresses. If the health check for the alias address is successful, the system marks all associated objects up. If the health check for the alias address is not successful, then the system marks all associated objects down.
  22. For Alias Service Port, specify an alias port or service for the monitor to check, on behalf of the pools or pool members with which the monitor is associated.
    The default setting is *All Ports. If the health check for the alias port or service is successful, the system marks all associated objects up. If the health check for the alias port or service is not successful, then the system marks all associated objects down.
  23. For IP DSCP, specify the differentiated services code point (DSCP).
    DSCP is a 6-bit value in the Differentiated Services (DS) field of the IP header. It can be used to specify the quality of service desired for the packet. The valid range for this value is 0 to 63 (hex 0x0 to 0x3f). The default is 0 (zero).
  24. For Adaptive, specify whether adaptive response time monitoring is enabled for this monitor.
    Option Description
    Enabled The monitor determines the state of a service based on how divergent from the mean latency a monitor probe for that service is allowed to be. When enabled, you can set values for the Allowed Divergence, Adaptive Limit, and Sampling Timespan monitor settings.
    Disabled The monitor determines the state of a service based on the Interval, Up Interval, Time Until Up, and Timeout monitor settings.
    If you select Enabled for this control, three additional controls are displayed.
  25. If you enabled Adaptive, for Allowed Divergence, specify the type of divergence used for adaptive response time monitoring.
    Option Description
    Absolute The number of milliseconds the latency of a monitor probe can exceed the mean latency of a monitor probe for the service being probed. Tip: In typical cases, if the monitor detects three probes in a row that miss the latency value you set, the pool member or node is marked down.
    Relative The percentage of deviation the latency of a monitor probe can exceed the mean latency of a monitor probe for the service being probed.
  26. If you enabled Adaptive, for Allowed Divergence, specify the absolute number of milliseconds that may not be exceeded by a monitor probe, regardless of Allowed Divergence.
    For a probe to be considered successful, this value applies regardless of the value of the Allowed Divergence setting.
  27. If you enabled Adaptive, for Sampling Timespan, length, in seconds, of the probe history window that the system uses to calculate the mean latency and standard deviation of a monitor probe.
  28. Click Save & Close.