I am tuning the performance of our mail server. We collect information in our logs every 10 seconds including qshape, iostat, free and mpstat. It seems that the maxproc parameter in master.cf is important for us as we can see the size of the queues decrease as we increase maxproc -- as expected.
We are currently running with qshape showing 1,000 emails in the incoming/active queue maximum -- all less than 5 minutes. Our processor load average is less than 1.0 running four cores. We have 4 GB of memory and 2.8 GB available and no swapping. 80% of the email sent is taking advantage of connection reuse for the large ISPs. We have four smtp transports with 64 maxproc each. Should we try to reduce the size of the queue to zero by increasing maxproc? Is there some advantage to having moderate size queues for connection reuse and the like? What is the best way to tell how many processes per smtp transport are actually being used at a point in time? I would like to add this to our logs every 10 seconds. Thanks, Greg www.RayStedman.org
