Hi, I am helping someone with a system that makes use of the msgsnd and msgrcv calls to xfer messages between components using Queues and Fifos:
I/O Listener -> Router -> Process Module I/O Sender <- Router <- Process Module The problem is the performance - on a medium-size Unix system (e.g. 4 CPU HP system) they get 600 messages through the system per second, when the Process Module is handling database enquiries. On a 4 CPU windows system with Cygserver (4 x Intel Xeon 3.2GHz, 3.5Gb RAM) they are struggling to get even 4-5 messages through the system in a second, even with a *dummy* Process Module which does no database access, only returning a 'success' message! We have tested with Cygwin 1.5.24-2 and 1.5.25-5 We have turned off Hyperthreading and disabled the anti-virus from scanning the application and cygwin folder structures on the servers, and amended cygserver.conf, but are hitting this wall in the performance. (response msgs can be up to 4096 bytes, I set # kern.ipc.msgssz: Size of segment in bytes. Must be a power of 2 value. # Default: 8, Min: 8, Max: 1024 kern.ipc.msgssz 256 # kern.ipc.msgmnb: Maximum no. of bytes in a single message queue. # Default: 2048, Min: 1, Max: 65535 kern.ipc.msgmnb 65535) I cannot see how to enable any kind of performance monitoring in Cygserver, and through the debug in their system I see that the responses from Cygserver can have significant delays at times, but I can't see any pattern to the delays. Please can anyone suggest what to look into to track down where the problem may be, and what diagnostics / debug could help me? I cannot find any discussions on problems with Cygserver performance on the net, so I have to assume it is a problem with their setup ... but it's happening on their two test servers, and also on site! Gary ___________________________________________________ Gary Rowe, Dublin, Ireland www.rowandelle.com -- Unsubscribe info: http://cygwin.com/ml/#unsubscribe-simple Problem reports: http://cygwin.com/problems.html Documentation: http://cygwin.com/docs.html FAQ: http://cygwin.com/faq/
