Link to home
Start Free TrialLog in
Avatar of drlchen
drlchen

asked on

Apache Response Time in Access Log How is it measured

How is "Response Time" in the apache access log measured?
Is it measured by from the time the request was received and sent to the client?
or is it measured from the time the server received the request sent the data back to the client and then receive an ACK from the tcp handshake?

SOLUTION
Avatar of arnold
arnold
Flag of United States of America image

Link to home
membership
This solution is only available to members.
To access this solution, you must be a member of Experts Exchange.
Start Free Trial
Avatar of drlchen
drlchen

ASKER

I also found this definition on the web:

http://stein.cshl.org/~lstein/torture/torture.html 
It is the total time to send the request to the server and receive the complete response back. Lower response times are better.

This tells me it also measures the network time but the I found another article suggesting Response Time is the processing time.

Header set X-Request-Processing-Time: %D

http://prefetch.net/blog/index.php/2007/01/02/measuring-apache-request-processing-time/


ASKER CERTIFIED SOLUTION
Link to home
membership
This solution is only available to members.
To access this solution, you must be a member of Experts Exchange.
Start Free Trial
Avatar of drlchen

ASKER

ok after some testing it looks like it includes network time. also

The %T and %D directives refer to the time it takes to handle the entire transaction, including the amount of time it takes for the client to transmit data. If you see wide variances in the amount of time it takes to serve the same file, it may be related to a web client network problem.

Also onlamp.com confirms this
http://onlamp.com/pub/a/apache/2004/04/22/blackbox_logs.html?page=4