> Am 21.12.2014 um 10:13 schrieb Jonathan K. Tullett > <jonathan+postfix@dda.systems>: > > Greetings, > > I've been using Postfix for many years - since about 2002 - and I've finally > come across a problem I've not been able to resolve by searching online, or > from tapping into my personal network. So I have come to you all for help. > > I have two machines: > Machine A: My primary 8 core Xeon 2.27GHz, 24Gb RAM primarily running Postfix > 2.6.6 (SLES 6.6 distro) > Machine B: A test box 16 core Xeon 2.2Ghz w/16Gb RAM, primarily running > Apache, RabbitMQ, MemcacheD and finally Postfix 2.9 (Ubuntu 12.04). > > Machine A is used to distribute to a couple of double-opt-in mailing lists a > week, total recipients between 30,000 and 180,000. The 'sendmail' binary is > used to inject messages into the queue from a distribution manager. > > The setup on the server is simple: Postfix with two header checks to prepend > a List-Unsubscribe and a Precedence header, and using an OpenDKIM milter for > Domain Keys signing. Nothing other than that. > > Prior to the last week of October using the distribution manager, it was > possible on machine A to inject around 25 messages (full size - about 70k > each) a second into the maildrop queue. > > Since the end of October, that number has dropped to 16 a second on a good > day. > > I wrote a test script (basic for-loop which sent a 1 line, 500 byte email) > and disabled the milters (OpenDKIM and header_checks), it took 12.75 seconds > to inject 500 messages onto Machine A. > > As a test, I ran exactly the same script on Machine B. It injected 1000 > messages (about 500 bytes in size) into the maildrop queue in 4.95 seconds. > > (I appreciate Machine B is slightly higher spec, but I wouldn't expect such > disparity!) > > I ran qshape during the last mailing on machine A, and the machine was able > to send mails out as fast as it received them; there was no congestion in any > of the queues (maildrop, incoming, outgoing, etc). > > I have no machine stats prior to October - I only came onto the project last > week - do I don't know what (if anything) changed on that week to cause > performance to drop so suddenly. > > I have run read/write tests on both disks - Machine A and B do about > 500Mb/second reads, and 380Mb/second writes; all looks OK. > > I'm not sure why SLES 6.6 was chosen as it was a new build in August, but > know only Postfix 2.6.6 is officially available in the repo for that > distribution. I have 2.11.3 built and ready to go on that machine but would > prefer not to just upgrade on the off-chance it'll 'fix' the problem when > there may be something I'm missing entirely. > > Have there been huge improvements to the efficiency of the code base between > 2.6 and 2.9 (or 2.11)? Does anyone have suggestions on where else I can look > for the cause?
Does atop exist for SLES6.6? I love all these *top slabtop, htop and atop. With atop I could find I/O problems on my monitoring server. Maybe one of such tools might give you information? Christian -- Bachelor of Science Informatik Erlenwiese 14, 36304 Alsfeld T: +49 6631 78823400, F: +49 6631 78823409, M: +49 171 9905345 USt-IdNr.: DE225643613, http://www.roessner-network-solutions.com
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