Re: [Serusers] Server dimensioning

Hi, I think in most of the cases it is worth increasing the number of child processes. A child process is blocked during the SIP msg processing, and if there is any problem the blocking can take a lot of time, for example the processes can be blocked because of a not responding DNS server. When this happens SER cannot handle new incoming messages if there is no more child process available. Btw, even if there is still a child process available, if the new msg requires a DNS query again then there is not too much difference. But if the new msg is routed without being blocked again then it will be successfully handled by SER while the other messages are waiting for the response of the DNS server. (I think it is also worth setting the timeout of the DNS query (and other external queries) to a low value.) And it is always good to increase the the number of processes when the limit is not the CPU but SER waits for some external source too much, for example lots of database queries to another server. -- SER can start processing the new messages at least while the previous ones are still waiting for the database result. The memory usage is not increased too much by the number of processes because of the copy-on-write strategy of the OS. The number of file descriptors needed is increased, and each child process keeps a separate DB connection to the server. So you may have to increase the limits. Also keep in mind that when the number of processes is too high and they simultaneously try to access some shared resource that involves locking then the risk of contention is also high. So in general, it is better to test it by yourself because the performance heavily depends on your configuration and the servers SER tries to access during the msg routing. Include the failure cases in your tests to find the optimum number of processes. Regards, Miklos On 06/24/2009 02:45 PM, inge wrote: