Server processing time in tomcat access logs

tomcat access-log
user3626166 picture user3626166 · May 12, 2014 · Viewed 13k times · Source

In order to debug a performance issue I enabled access logs in tomcat. We are not using any apache server. Its the embedded tomcat that we are using.

I'm using following pattern for access logs.

access-patten = %h %l %u %t "%r" %s %b %D

%D = time at which first byte of the request is received ~ time at which last byte of the response is send.

So %D includes network latency as well.

But how do I print time difference between first byte of the request received and first byte of the response sent.

Answer

miginside picture miginside · Jun 9, 2015

As mentioned by Tomer, since Tomcat version 7.0.42 there is a new log element '%F' available in the AccessLogValve implementation. You can find a better description of the difference between '%D' and '%F' in the case description:

Bug 55102 - Add ability to report time taken to prepare response:

Tomcat's AccessLogValve is able to report the time taken to send an entire request using %D. This is the total processing time and may be affected by network conditions. It is sometimes useful to be able to record the time taken by the server to prepare the response and send the first content to the client.

Attached is a patch that records the time the response is committed and then allows that to be reported in the access log using a '%F' pattern (which is the same as used by the mod-log-firstbyte module for HTTPD).

Related questions

How to deploy a war file in Tomcat 7

I have copied the sample.war file into the webapps directory of Tomcat, and I can access localhost:8080. Now how will Tomcat deploy it, I mean do I need to open it in browser? How can I access the application?

Read More
Several ports (8005, 8080, 8009) required by Tomcat Server at localhost are already in use

I'm getting the following error when I try to run a simple JSP program on Tomcat in Eclipse. Several ports (8005, 8080, 8009) required by Tomcat v6.0 Server at localhost are already in use. The server may already be running in another process, …

Read More
"Server Tomcat v7.0 Server at localhost failed to start" without stack trace while it works in terminal

So got this project which worked just fine before the weekend (have other problems, but at least Tomcat launched). Now when I try to launch the Tomcat server it immediately gives the following error: Server Tomcat v7.0 Server at localhost …

Read More