On Wed, 2005-08-24 at 17:49 +1000, Badai Aqrandista wrote: > I have put a reverse procy in front of my mod_perl servers and I have set > MaxClient to 30. I have tried setting it to 50, but it slows down the > response time.
Are you running out of memory when you set it to 50? That's what you are trying to avoid by setting MaxClients. Also, you are sending your load test through the proxy server, and that has a much higher MaxClients setting, right? > I ran httperf to create 50 connections. This is the result: > > 1 connections per second -> avg reply time = 103953.7 ms > 10 connections per second -> avg reply time = 123167.2 ms > 20 connections per second -> avg reply time = 121483.7 ms > 30 connections per second -> avg reply time = 114411.3 ms > 40 connections per second -> avg reply time = 130168.7 ms > 50 connections per second -> avg reply time = 130457.4 ms That looks pretty good to me. It scales better than linearly, i.e 50 conns is not 50 times slower than 1 conn. > When only creating 1 connection, the avg reply time = 3289.4 ms That doesn't seem to be what your numbers above say. > I have no idea where to start fixing this. It seems that the more connection > there is, the higher the avg reply time. That's true for any web server. More connections means the machine is doing more work and running more processes, so of course it will be slower. All you need to do is make sure you are not running out of memory and going into swap. If the performance you get is not enough for you, look for the bottleneck. This could be running out of CPU, running out of memory, or contention for a shared resource like a database. Then you fix it, by changing code or buying hardware. - Perrin
