Re: Slower bounce-back of commit messages

From: Stephen Frost <sfrost(at)snowman(dot)net>
To: Stefan Kaltenbrunner <stefan(at)kaltenbrunner(dot)cc>
Cc: Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us>, pgsql-www(at)lists(dot)postgresql(dot)org
Subject: Re: Slower bounce-back of commit messages
Date: 2018-11-20 20:01:11
Message-ID: 20181120200111.GK3415@tamriel.snowman.net
Views: Raw Message | Whole Thread | Download mbox | Resend email
Thread:
Lists: pgsql-www

Greetings,

* Stefan Kaltenbrunner (stefan(at)kaltenbrunner(dot)cc) wrote:
> On 11/14/18 10:52 PM, Tom Lane wrote:
> > It seems like sometime in the past few days, the throughput of the
> > PG mail system dropped substantially. The particular symptom I'm
> > noticing is that when I push multiple commits, it used to be
> > that the pgsql-committers traffic came back (a) within a few seconds
> > and (b) all together. Now it takes a few minutes for them to trickle in,
> > as in this example of seven commits that were pushed together:
> >
> > From pgsql-committers-owner+M15-102287(at)lists(dot)postgresql(dot)org Wed Nov 14 16:40:31 2018
> > Subject: pgsql: Doc: remove claim that all \pset format options are unique in
> > From pgsql-committers-owner+M15-102288(at)lists(dot)postgresql(dot)org Wed Nov 14 16:40:35 2018
> > Subject: pgsql: Doc: remove claim that all \pset format options are unique in
> > From pgsql-committers-owner+M15-102292(at)lists(dot)postgresql(dot)org Wed Nov 14 16:43:57 2018
> > Subject: pgsql: Doc: remove claim that all \pset format options are unique in
> > From pgsql-committers-owner+M15-102289(at)lists(dot)postgresql(dot)org Wed Nov 14 16:44:20 2018
> > Subject: pgsql: Doc: remove claim that all \pset format options are unique in
> > From pgsql-committers-owner+M15-102290(at)lists(dot)postgresql(dot)org Wed Nov 14 16:44:34 2018
> > Subject: pgsql: Doc: remove claim that all \pset format options are unique in
> > From pgsql-committers-owner+M15-102293(at)lists(dot)postgresql(dot)org Wed Nov 14 16:44:43 2018
> > Subject: pgsql: Make psql's "\pset format" command reject non-unique
> > From pgsql-committers-owner+M15-102291(at)lists(dot)postgresql(dot)org Wed Nov 14 16:44:52 2018
> > Subject: pgsql: Doc: remove claim that all \pset format options are unique in
> >
> > I've also noticed slower turnaround on some of the other lists.
> > What's up?
>
> we have recently spent a fair amount of effort in optimizing delivery
> times for large delivery bursts (especially concurrent approvals for
> mails on -announce) which caused very large load on the emailinglist box
> and way too aggressive backoff in delivery afterwards.
> That aggressive backoff caused excessive delays for a very large number
> of recipients - the current setup copes with that scenario much better
> however it puts deliveries for smaller lists (like pgsql-committers) at
> a disadvantage because we stepping down aggressive deliveries a little
> bit too early.
> We are still working on further refining the system but as with every
> optimization if you optimize for one scenario you might put another one
> at a disadvantage :(

We have now taken the next step in 'optimization' and basically thrown a
bunch more hardware at the problem (well, and some other minor tuning,
but most of it was adding a bunch more CPUs). We will continue to keep
an eye on things, of course, and continue to tune but hopefully this
will help.

Thanks!

Stephen

In response to

Browse pgsql-www by date

  From Date Subject
Next Message Ray O'Donnell 2018-11-27 09:34:16 Not receiving emails from pgsql-general
Previous Message Alvaro Herrera 2018-11-18 15:05:13 Re: Wiki editor request