We are starting to see our server hitch and become unresponsive more and more. Sometimes it's for 30 seconds and others for a couple of minutes. When it is unresponsive; webmail, mail clients, and the admin page time out. I have yet to remember to try to ping the server when this happens but I will do this the next time that I notice it.
What I'm wondering is the best way to diagnoise this issue. I have done some looking through the logs (mailboxd.csv, myslow.log, and the mailbox.log). Not a great deal is really jumping out at me but I'm not too certain where I should be looking. Any help that you can provide so that I can pin this thing down would be greatly appreciated. We are running Version 5.0.11_GA_2695.UBUNTU8.FOSS Nov 17, 2008.
Here's something that I did see in the mailbox.log at the time of our most recent disruption this morning. Thanks.
2011-01-17 08:11:58,404 INFO [Pop3Server-18419] [ip=BLANKED OUT;] pop - connected
2011-01-17 08:11:58,469 INFO [Pop3Server-18419] [ip=BLANKED OUT;] pop - -ERR invalid username/password (PASS ****)
2011-01-17 08:15:31,595 INFO [Pop3Server-18419] [ip=BLANKED OUT;] pop - disconnected without quit
2011-01-17 08:15:31,595 INFO [Pop3Server-18419]  ProtocolHandler - Handler exiting normally
2011-01-17 08:15:31,685 INFO [Pop3Server-18420] [ip=BLANKED OUT;] pop - connected
2011-01-17 08:15:31,686 INFO [Pop3Server-18420] [ip=BLANKED OUT;] ProtocolHandler - Exception occurred while handling connection
java.net.SocketException: Broken pipe
at java.net.SocketOutputStream.socketWrite0(Native Method)
at java.net.SocketOutputStream.socketWrite(SocketOutp utStream.java:92)
at java.net.SocketOutputStream.write(SocketOutputStre am.java:136)
at java.io.BufferedOutputStream.flushBuffer(BufferedO utputStream.java:65)
at java.io.BufferedOutputStream.flush(BufferedOutputS tream.java:123)
at com.zimbra.cs.pop3.Pop3Handler.sendLine(Pop3Handle r.java:373)
at com.zimbra.cs.pop3.Pop3Handler.sendResponse(Pop3Ha ndler.java:362)
at com.zimbra.cs.pop3.Pop3Handler.sendOK(Pop3Handler. java:337)
at com.zimbra.cs.pop3.Pop3Handler.startConnection(Pop 3Handler.java:125)
at com.zimbra.cs.pop3.TcpPop3Handler.setupConnection( TcpPop3Handler.java:42)
at com.zimbra.cs.tcpserver.ProtocolHandler.run(Protoc olHandler.java:126)
at EDU.oswego.cs.dl.util.concurrent.PooledExecutor$Wo rker.run(Unknown Source)