Hi folks, I am writing to seek explanations about some strange things we have been seeing. In our attempt to get Apache to compress dynamic content (not static), we turned off compression at the loadbalancer level and got dynamic compression working with deflate module.
We’ve been testing this change using Jmeter, without and with deflate module config, and found some interesting results with regards to latency. Latency decreased instead of increasing slightly when we used deflate to compress dynamic content. We noticed no significant differences in load averages in all the multiple iterations of testing we did. Often, they were slightly higher or about the same, and had little to zero adverse impact. We are not worried about CPU utilization. But since apache is doing the extra work of compressing on the fly with deflate module now, we thought latency would increase slightly. The average response times went down because we are serving much smaller files now. But latency(the time before first byte is sent) should have increased because it has to do all the extra work of compressing which it didn’t have to do before. But we see that latency went down too. It’s a good side-effect but we are not sure what is causing it. I am clueless why something like this could happen. Would really appreciate any answers. Thanks, Nishanth
