Tuesday, September 15, 2009

Fear, Uncertainty, and Doubt - Apache Style

Okay, so I have been afraid. I have been scared. And, yes, I have had doubt. It has always been my fear to not run rewrite logs - even for a second - on live systems.

Well, I am now over that one. Last night I set up rewrite logs on our apache servers.

# < IfDefine serverA >
#RewriteLog 9
#RewriteLog /logs/prod/rewrite_logs/www.rewrite.log.serverA
#</IfDefine>
#<IfDefine serverB>
#RewriteLog 9
#RewriteLog /logs/prod/rewrite_logs/www.rewrite.log.serverB
#</IfDefine>
#<IfDefine serverC>
#RewriteLog 9
#RewriteLog /logs/prod/rewrite_logs/www.rewrite.log.serverC
#</IfDefine>
#<IfDefine serverD>
#RewriteLog 9
#RewriteLog /logs/prod/rewrite_logs/www.rewrite.log.serverD
#</IfDefine>

Now, I did not run them for long - maybe 3-4 minutes.

Performance was fine - granted I was not running them during peak performance.

Speed of filling logs was acceptable - about 1Meg per second per box.

So, I ended up with about 10Gig of logs by the time I did my testing and got them turned off.

However, they didn’t really tell me much - even at RewriteLog 9. They basically told me most of what I was already seeing. This was basically that my stanza was being ignored. However, it was interesting to watch and see that it did indeed parse all our stuff, which, at least at some level given the shear number of rewrites we have, does slow the systems down some. Fortunately, we are on fairly modern equipment, so it can handle the rush.

So, for both of you reading this, do not be as I have been. Do not be afraid to write out those rewrite logs. Do not leave them running for long unless you got LOTS of hard drive space.