Before you can investigate server
latency, you need to have created an HTTP Analytics profile that is logging statistics
internally on the BIG-IP® system. The HTTP Analytics profile must
be associated with one or more virtual servers, or with an iApps®
You can review statistics concerning
server latency on the HTTP Overview chart. Server latency is how long it
takes (in milliseconds ) from the time a request reaches the BIG-IP system, for it to
proceed to the web application server, and return a response to the BIG-IP system.
On the Main tab, click
The Overview screen opens and displays current HTTP statistics averaged
over the last hour. You can see charts on the left and a list of dimensions on
Scroll down to the Avg Server Latency chart.
The chart shows the server latency for all applications and virtual
servers associated with all Analytics profiles.
To view server latency for a specific application, from the dimensions on the
right, expand Applications and select only that
latency only for the selected application.
To see more detailed latency statistics for any expanded dimensions, click the
handle at the top of the dimensions column,
Tables containing detailed statistics for the items in the dimensions
In the table, hover over the headings to see the full names of the columns, and
view the data.
Latency (ms) shows the average server latency in
Latency (ms) shows the minimum server latency in
Latency (ms) shows the maximum server latency in
To view the graphic charts and dimensions again, click the handle on the top
left of the table.
To view server latency for a specific virtual server, from the dimensions on
the right, expand Virtual Servers and select only that
You can clear all filter selections or those for a dimension.
- To clear all selections,
click the gear icon at the top of the column and select Clear
- To clear selections for a
dimension, click the options icon (three horizontal lines to the left of the
title), and select Clear Selection.
If further investigation is needed, select other dimensions to show latency for
other entities, for example, specific pool members, URLs, countries, or client
Tip: If you are concerned
about server latency, you can configure the HTTP Analytics profile so that it sends
an alert when the average server latency exceeds a number of milliseconds for some
period of time. See Getting an alert when server latency is