On 28/09/22 23:11, Punyasloka Arya wrote:
We have our squid 3.5 proxy running on centos 6 for 500 users Desktop video conference application Microsoft Team Meetings sessions and other VC apps often get disconnected. Audio goes off and reconnects automatically. At the same time browsing and other applications work fine. At the same time SQUID load is normal. we are clueless where to look into the system Any clues to fine tune the underlying parameters like File desriptors, cahce parameters etc.
Please first check whether Squid is actually involved with those software transactions. Typically those type of communications should be using RTSP/RTMP or VoIP protocols which Squid-3 does not support.
When Squid-3 does handle CONNECT for non-HTTP protocols (including encrypted HTTPS) its involvement is purely that of shuffling bytes between client and server. So the things to look for there are TCP level network issues (eg TCP, NAT, or router cache timeouts) closing connections unexpectedly.
If you have Squid Delay Pools configured that may also be interfering with connections that need high traffic flow rates.
Check how much traffic Squid is handling at the time(s) these issues occur. Squid-3.5 has upper limits of around 19K requests/second and ~63K concurrent client connections (on Linux/BSD, much lower on Windows). If either of these limits are encountered traffic speeds *will* drastically reduce speed until the clients adjust to a lower level. - The fix for these if you actually hit the upper limits is to use more Squid instances (on different hardware, not VMs on same HW) to share the traffic load. - If the speed drop occurs before hitting the limits you can try optimizing squid.conf settings (ACL sequence in particular), TCP stack settings (ie. ephemeral ports use and/or TCP flow controls) for performance.
Also check cache.log to see if Squid, workers, or helpers are halting/crashing at all. These are not very consistent in Squid-3 but should show up as one or more "FATAL", "ERROR", "assertion failed", or "unhandled exception", or "halted" messages. - The fix here is obviously to figure out and prevent the crashes occuring. Each log message and ones above it should provide some hints to help with troubleshooting.
FWIW, Squid-3.5 is long out of support and AFAIK CentOS 6 is also. HTH Amos _______________________________________________ squid-users mailing list squid-users@xxxxxxxxxxxxxxxxxxxxx http://lists.squid-cache.org/listinfo/squid-users
