Hi All, I am facing a very strange issue with the pop3 server for the past one week. I run my mail service using sendmail & use UW-IMAP for POP3 & IMAP service. We have around 5000 users. Suddenly for the past one week I am facing very slow connections for POP3 alone on that server. Other services such as SMTP, IMAP, telnet, ssh etc work fine. Assuming that UW-IMAP may have an issue, I download the latest dovecot, compiled it and installed it. This also gives the same issue. I do not any firewall issues nor iptables is enabled. I have checked on the network to ensure that I do not have any kind of virus or DoS attacks using an IDS. I am unable to see any 'Strange' messages in /var/log/messages or maillog. What is strange is that it works one day without any issues and the next day the problem persists. Even a telnet to localhost on port 110 is very very slow. Can someone help with any ideas on how to troubleshoot? This is our production box. Thanks V S Rao
On Tue, 2009-04-28 at 00:12 -0700, V S Rao wrote:> Even a telnet to localhost on port 110 is very very slow.Which part of it exactly is slow? For example in a typical pop3 connection you have: Trying 127.0.0.1... Connected to localhost. Escape character is '^]'. +OK Dovecot ready. user xyz +OK pass asd +OK Logged in. Like is it hanging after "Trying", "Connected", "pass", .. ? -------------- next part -------------- A non-text attachment was scrubbed... Name: signature.asc Type: application/pgp-signature Size: 197 bytes Desc: This is a digitally signed message part URL: <http://dovecot.org/pipermail/dovecot/attachments/20090429/eacf0587/attachment-0002.bin>
Great. Thank you so much for responding. It hangs at Tying 127.0.0.1 The funny part is that one day it works fine and the next day it just hangs. And its not that the service is completely unresponsive. If 200 users try to connect, 10 get through and are able to download. However which 10 get through depends on luck! Its been going on for the past one week and really driving me crazy. I have changed everthing including the server, but the problem persists. How do I get a clue where the problem is? Am badly in need of help here. Regards V S Rao. ----- Original Message ----- From: "Timo Sirainen" <tss at iki.fi> To: "V S Rao" <viriyala at yahoo.com> Cc: dovecot at dovecot.org Sent: Wednesday, April 29, 2009 11:23:37 PM GMT +05:30 Chennai, Kolkata, Mumbai, New Delhi Subject: Re: [Dovecot] Slow connections with POP3 service On Tue, 2009-04-28 at 00:12 -0700, V S Rao wrote:> Even a telnet to localhost on port 110 is very very slow.Which part of it exactly is slow? For example in a typical pop3 connection you have: Trying 127.0.0.1... Connected to localhost. Escape character is '^]'. +OK Dovecot ready. user xyz +OK pass asd +OK Logged in. Like is it hanging after "Trying", "Connected", "pass", .. ?