On 02/05/18 05:17, Cody Herzog wrote: > Thanks very much for the quick response, Amos. > > > > For my use case, I would like Squid to exit when all client connections > have been closed or when the timeout occurs, whichever comes first. > Then Squids behaviour already matches your requirements. The "or when timeout occurs" is shutdown_lifetime and you do not have to do anything. > > My instances of Squid may be handling several persistent WebSocket > connections, and I don't want to disrupt those. I will occasionally need > to perform maintenance, so I want a safe way to stop Squid without > disrupting user activity. > Nod. It will also likely be handling CONNECT tunnels for other things. Be aware that these connections can last indefinitely - some have been known to last on a timescale of several weeks. If your maintenance is with squid.conf or things loaded by it use "squid -k reconfigure" instead of a restart cycle. Squid can reload its config fine with just a pause for any active clients - your netstat approach could be useful to pick a time with minimal connections to reload the config. > > I am using a fairly simple Squid configuration, with no caching, so I > suspect that I can simply monitor the number of active Squid TCP > connections using 'netstat', and then execute the second shutdown > command when I detect that all those connections are closed. > Since WebSockets is part of your situation netstat will almost certainly not work as well as you suspect. These connections can be very surprising in their lifetimes. > > I've been using the following command to count the number of active > Squid TCP connections of port 443, which is the only port I use: > > > > netstat -nat | grep ".*:443.*:" | grep ESTABLISHED | wc -l > > > > That seems to give me what I want. > Hmm, you might be able to get more useful info from the Squid filedescriptors report. squidclient mgr:filedescriptors > > > Is it possible that bad things could happen by stopping Squid when I see > that all the TCP connections have closed? Should not be any bad things if you just use -k shutdown (twice). Squid will take the time it needs for a clean (but immediate) shutdown so long as you only do it twice, not more and do not use "kill" command. Amos _______________________________________________ squid-users mailing list squid-users@xxxxxxxxxxxxxxxxxxxxx http://lists.squid-cache.org/listinfo/squid-users
