timeout problem on inbound and outbound SMTP
in [Postfix]
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From: Noel Jones on 4 May 2010 16:00 On 5/4/2010 2:51 PM, Nataraj wrote: > Charles Gregory wrote: >> On Tue, 4 May 2010, Nataraj wrote: >>> Enclosed is a tcpdump of a telnet connection where nothing was typed, >>> i.e. I telnetted to the smtp server and 5 seconds later the server >>> closed the connection. >> >> THIS IS NORMAL. As I said previously, type the MAIL FROM, RCPT TO, and >> DATA commands, send a couple of ilnes, THEN wait and time the timeout. >> >> How about those logs showing a complete mail 'life cycle'? >> >> - C > I have attached tcpdump-with-commands.txt where I pasted with the mouse > helo mymail.com > mail from:<me(a)mymail.com> > > I then waited and it still timed out in 5 seconds. > > I think the timeout should be whatever the smtpd_timout parameter is set > to (300s in my case), unless the stress code is enabled and operating, > in which case it should be set to the stress config timeout parameter). > 5 seconds is not a normal timeout for my configuration. I am enclosing a > tcpdump of a telnet session to the mail server which serves this mailing > list (I hope it's not considered abusive to use it as a reference:-)), > which times out after 21 seconds (probably because it is configured that > way). 5 seconds is just too short, and it should change based on my > configuration, which it is not doing. > > As I've mentioned, I can't type fast enough to my server to prevent > timeouts, but if I reenable pipelining, I can paste smtp commands and > submit messages, only if I paste them all at once (and pipelining is > enabled). > > Also, please don't loose sight of the fact that all of my timeouts are > screwed up, i.e. inbound smtp, outbound smtp as well as transport and > policy. Maybe this is not a postfix problem, or postfix is having some > strange interaction with something going on in the OS (or a vmware > clocking problem or something). > > Nataraj > You can try setting smtpd_timeout and smtp_connect_timeout to riduclously high values (maybe 3000s for testing) to see if it makes any difference. If it doesn't change anything, then this problem is outside postfix somewhere and you'll need to examine other parts of your system. I suppose this could be some sort of a clock issue, but I've never heard of one this extreme. Still, the problem and solution would both be outside postfix. -- Noel Jones
From: Nataraj on 4 May 2010 16:02 Charles Gregory wrote: > On Tue, 4 May 2010, Noel Jones wrote: >> The described behavior suggests smtpd_timeout is set for 4s, but that >> parameter isn't in the postconf or master.cf shown to the list. > > Or the poster has a front-end on his mail server, and that is why I > asked for a complete log of the 'lifecycle' of the mail, so we can > spot if he is getting the timeout from some other piece of software. > > - C I do not have a front end on my mailserver. All incoming mail comes directly into postfix. I am running a vpostmaster install which is not a front end, but simply provides policy and transport agents that interface to postfix. Postfix is the standard install that comes with CentOS, though vpostmaster and I have changed the config files. Here are the 3 lines that get logged for a timeout. May 4 12:56:07 aspen postfix/smtpd[1277]: connect from 173-16-199-243.client.mchsi.com[173.16.199.243] May 4 12:56:11 aspen postfix/smtpd[1277]: timeout after CONNECT from 173-16-199-243.client.mchsi.com[173.16.199.243] May 4 12:56:11 aspen postfix/smtpd[1277]: disconnect from 173-16-199-243.client.mchsi.com[173.16.199.243] Nataraj
From: Nataraj on 4 May 2010 16:09 Noel Jones wrote: > > > You can try setting smtpd_timeout and smtp_connect_timeout to > riduclously high values (maybe 3000s for testing) to see if it makes > any difference. If it doesn't change anything, then this problem is > outside postfix somewhere and you'll need to examine other parts of > your system. > > I suppose this could be some sort of a clock issue, but I've never > heard of one this extreme. Still, the problem and solution would both > be outside postfix. > > > -- Noel Jones Thank you Noel. You have been helpful in convincing me that I have reviewed the obvious configuration issues. I guess one option at this point is to try to fire up the debugger on an SMTPD process and see what's really going on (or add some debugging code which logs the details). Nataraj
From: Nataraj on 4 May 2010 16:15 N. Yaakov Ziskind wrote: > Noel Jones wrote (on Tue, May 04, 2010 at 02:33:48PM -0500): > >> On 5/4/2010 2:16 PM, Charles Gregory wrote: >> >>> On Tue, 4 May 2010, Nataraj wrote: >>> >>>> Enclosed is a tcpdump of a telnet connection where nothing was typed, >>>> i.e. I telnetted to the smtp server and 5 seconds later the server >>>> closed the connection. >>>> >>> THIS IS NORMAL. As I said previously, type the MAIL FROM, RCPT TO, and >>> DATA commands, send a couple of ilnes, THEN wait and time the timeout. >>> >>> How about those logs showing a complete mail 'life cycle'? >>> >>> - C >>> >> No, it's not normal. When you telnet to a postfix smtpd, >> postfix will sit there patiently for $smtpd_timeout before it >> disconnects if you don't type anything. >> >> The described behavior suggests smtpd_timeout is set for 4s, >> but that parameter isn't in the postconf or master.cf shown to >> the list. >> >> I don't think there's anything else we can do for the OP. >> >> -- Noel Jones >> > > If the timeout is really set to 4s, can it be overriden in master.cf? > Wouldn't that be a useful workaround, or at least a diagnostic? > > Thanks. > > I have tried already to change timeout parameters with no change in the behaviour. Thank You, Nataraj
From: Charles Gregory on 4 May 2010 16:24
On Tue, 4 May 2010, Nataraj wrote: > I have attached tcpdump-with-commands.txt where I pasted with the mouse > helo mymail.com > mail from:<me(a)mymail.com> What use is that? Post your LOGS. You know, /var/log/mail with relevant log entries from psotfix and any other program that handles your mail... - C |