Why is one zeus.web process doing all the work on my multi-CPU machine?

On a multi-processor machine, Zeus creates one process per processor.You may notice from the output of the 'ps' command that when theserver is only moderately loaded, only one of the Zeus processes (letus say PID 347) seems to be using much CPU time whilst the others areidle.

The reason for this is that there isn't much work to do. All the child processes will attempt to get new work from the shared server socket. The first process to grab the work will get it.

If none of the processes are very busy, they will all try at the same time. Then the OS scheduler will pick one. If process 347 is busy at the time when a new connection comes in, it won't be racing to grab the new work along with the other children, and one of the other children would get used. When the server is working hard, all the children will be used equally. When the server is doing virtually nothing, only one child is used.

For very high-performance solutions, it is possible to use a combination ofthe tuning!unique_bind and tuning!num_childrentunables to cause the zeus.web children tobind to different hosted IP addresses, rather than just different networkinterfaces. This may be of benefit to very high-bandwidth sites.

Content Manager [Administrator] 19 September 2005