Hiii, How to improve postfix server sending speed, any parameters required in main.cf file so confirm me. My requirement is we will send minimum 500 to 600 email in less then 1 minutes.
Please give the suggestion On Fri, Oct 29, 2010 at 9:05 PM, Christian Rohmann <crohm...@netcologne.de>wrote: > Hey postfix-users, > > we are currently analyzing very strange postfix behavior which I can > only describe as lockup or freeze. > Honestly we reached our abilities to gather more info and to find the > root cause of this issue. > > You are my last hope obi wan ... eh Wietse .... > > > --- Setup / Configuration --- > We are running three VMware ESX 4.1 guests (multiple VMware hosts) with > Debian Lenny amd64. > Each machine has 8 virtual CPUs and 4GB of RAM. We are using the Debian > lenny postfix package (2.5.5) and now moved up to 2.7.1 which we > backported (problems remained unchanged). > Each instance of postfix recieves about 200-300 mails/minute. The mail > addresses of the incoming emails are checked using a relay_recipient_map > (proxymap + mysql) are rewritten (domain is changed) and then relayed > using a transport map towards a multi-A record containing two IPs. > > > --- Lockup Issues --- > The setup and configuration works like a charm for hours at a time and > all of a sudden it stops working leading to two issues (not at the same > time): > > 1) First issue was that suddenly smtp stopped delivering email to that > mutli-A record. We noticed a few thousand emails in the active queue (I > guess all emails where in the active queue by that time). We rule out > problems with the destination servers since the remaining postfix > instances still delivered mail during that time. Even the last > submission of email from the now locked up postfix finished without > issue. There are just no more tries to reach the destination. Postfix > also stops to deliver to both destination IPs at the same time. There > was no logging anymore, but from anvil giving us some statistics about > connection rates. > > 2) The second issue, occurring more often is that smtpd stopped > responding or doing anything acutally. Sometimes the number of processes > went to max (500) at other occurences it just stayed at like 30-50 but > symptoms where still the same. > > Looking at netstat all tcp connections to the smtpd processes went away > after some time.We believe that clients trying to deliver email to us > did disconnect due to reaching their timeout. > > Here is a sniplet of log from before and after the issue: > --- connect before and after lockup --- > Oct 29 12:57:35 mailserver postfix/smtpd[12457]: connect from > newsletter.xxx.de[xxx.162.xxx.28] > Oct 29 13:29:02 mailserver postfix/smtpd[12457]: 826C611FA8: > client=newsletter.xxx.de[xxx.162.xxx.28] > Oct 29 13:29:03 mailserver postfix/smtpd[12457]: lost connection after > RCPT from newsletter.xxx.de[xxx.162.xxx.28] > Oct 29 13:29:03 mailserver postfix/smtpd[12457]: disconnect from > newsletter.xxx.de[xxx.162.xxx.28] > --- / connect before and after lockup --- > There is not a single line of log from smtpd processes while being in > the locked up state. At 12:57:35 there is a last connect from a client, > no more log happens until we run "postfix reload" (! a reload is > sufficient) about half an hour later. Then the last few lines show that > the smtpd process is "alive" again talking to the now already > disconnected client. > > Also the master process is still there but not accepting anymore > connections until we issue "postfix reload". Here is an strace of the > master process: > --- strace on master-pid while locked up --- > 10648 alarm(333) = 307 > 10648 epoll_wait(13, > --- / strace on master-pid while locked up --- > > > Another strange thing is, that some of the last log entries contain > "UNKNOWN" instead of the IP: > --- smtpd connects towards UNKNOWN --- > Oct 29 13:05:02 mailserver postfix/smtpd[14196]: connect from > unknown[unknown] > Oct 29 13:05:02 mailserver postfix/smtpd[14196]: NOQUEUE: reject: > CONNECT from unknown[unknown]: 550 5.7.1 Client host rejected: cannot > find your reverse hostname, [unknown]; proto=SMTP > Oct 29 13:05:02 mailserver postfix/smtpd[14196]: too many errors after > CONNECT from unknown[unknown] > Oct 29 13:05:02 mailserver postfix/smtpd[14196]: disconnect from > unknown[unknown] > --- / smtpd connects towards UNKNOWN --- > > Anvil also gives statistics about this obscure client-IP "UNKNOWN": > --- anvil statistics for UNKNOWN --- > Oct 29 13:14:57 mailserver postfix/anvil[9312]: statistics: max > connection rate 92/60s for (smtp:unknown) at Oct 29 13:05:02 > Oct 29 13:14:57 mailserver postfix/anvil[9312]: statistics: max > connection count 1 for (smtp:unknown) at Oct 29 13:05:02 > Oct 29 13:14:57 mailserver postfix/anvil[9312]: statistics: max cache > size 413 at Oct 29 13:05:02 > --- / anvil statistics for UNKNOWN --- > > During the lock up we still see the *:25 listening socket of the master > process. When we tried to connect ourselves we just waited forever for a > connection or even a SMTP prompt. > > New incoming connections are in state "SYN_RECV": > --- netstat while locked up--- > Proto Recv-Q Send-Q Local Address Foreign Address State > tcp 0 0 x.x.x.143:25 xx.0.xx.217:58556 SYN_RECV > tcp 0 0 x.x.x.143:25 xx.115.xx.166:46355 SYN_RECV > tcp 0 0 x.x.x.143:25 xx.63.xx.197:37216 SYN_RECV > . > . > . > ---/ netstat while locked up--- > > > Again a "postfix reload" does fix the problem (for a few hours) and > postfix delivers the > 10,000 emails in the active queue in a few > seconds towards the two IPs from the DNS round robin and everything goes > back to normal for a few hours. > > > > I'm hoping for suggestions on what to look for or check, > TIA > > Christian > -- Incase of any further queries, Please feel free to mail me or contact me on the numbers provided below. Thanks & Regards, Ravindra Gupta Asst Manager - Tech Support Viva Infomedia Pvt. Ltd. 242, Oshiwara Industrial Centre, New Link Road, Opp. Oshiwara Bus Depot, Goregaon West, Mumbai 400104. Direct: +91.22.40310353 Board: +91.22.40310310 Email: ravin...@vivaconnect.in Viva Infomedia: Awarded as Best SME (E-Commerce) at CNBC Emerging India Awards 2009
