imap connection closed

[demchenko]

Hi,
i'm getting troubles with mail clients & zimbra imap: very often outlook shows error "imap4rev1 server closed connection; service busy", after which it cant connect to server until restarted several times; almost same thing with thunderbird - shows that server imap server closed connection and starts working only after hit "ok" many times.

I've set imap-related events loglevel to debug, but got no errors in mailbox.log;
the only errors i've found in any logfiles were in nginx.log (but they just copy ones that shows in clients":
"*5199 upstream sent invalid response: "* BYE post.mycompany.ru Zimbra IMAP4rev1 server closing connection; service busy" while reading response from upstream, client: 10.0.11.112, server: 0.0.0.0:993, login: "somelogin", upstream: 10.0.7.55:7143, [10.0.11.112:1384-10.0.7.55:993] <=> [10.0.7.55:39276-10.0.7.55:7143]"
server's load average not exceeding 4.0

Please help in solving this problem.

[demchenko]

as update:
found in mailbox.log this errors:
"2011-10-05 12:04:00,294 WARN [ImapServer] [] TcpServer/7143 - Thread pool is 100% utilized. 201 out of 200 threads in use.
2011-10-05 12:04:00,294 ERROR [ImapServer] [] TcpServer/7143 - cannot handle connection; thread pool exhausted
java.util.concurrent.RejectedExecutionException
at java.util.concurrent.ThreadPoolExecutor$AbortPolic y.rejectedExecution(ThreadPoolExecutor.java:1768)
at java.util.concurrent.ThreadPoolExecutor.reject(Thr eadPoolExecutor.java:767)
at java.util.concurrent.ThreadPoolExecutor.execute(Th readPoolExecutor.java:658)
at com.zimbra.cs.tcpserver.TcpServer.run(TcpServer.ja va:202)
at java.lang.Thread.run(Thread.java:662)"
timing excacly matches with mail clients errors.

how to increese this thread pool?

[gvillaran]

"Thread pool is 100% utilized. 201 out of 200 threads in use."

i think you need to increase the imap threads to more than 200.

[soba@ukw.edu.pl]

exactly - change your IMAP session limit (you can change it from Zimbra admin GUI).

[phoenix]

Originally Posted by demchenko

how to increese this thread pool?

A search gives the answer: site:zimbra.com +"thread pool" +imap - Yahoo! Search Results

[demchenko]

Thanks to all!
problem solved by increesing imap threads via web-admin and restart of zimbra.

[soba@ukw.edu.pl]

n/p

Always when you change IMAP/ POP session limit, you must restart your Zimbra server.