Recent (probably MacOS) mail app provoking endless cyrus.index writes on 2.3 server.

[ktm at rice.edu]

On Wed, Oct 14, 2015 at 07:43:47AM +1100, Bron Gondwana wrote:
> On Wed, Oct 14, 2015, at 00:26, ktm at rice.edu wrote:
> > The El Capitan Mac Mail was recently released. It definitely has a problem.
> > We saw our typical sync log size go from 10k when busy to 100k+. We are going
> > to recommend that people wait to upgrade to that release until the problem is
> > addressed.
> 
> I'll look into whether this is a problem (or as much of a problem) on later releases!
> Just to be clear - have you tracked the issue down to the EXPUNGE command using
> IO?
> 
> (It's unlikely that 2.3 will be patched to make EXPUNGE more efficient unless someone
> else wants to do it.  I've already spent a year fixing that code, and it's called 2.4)
> 
> Bron.

Hi,

It has not been much of a problem here, but out servers are spec-ed for peak load
and not average load. In the sync log, there are hundreds of lines like:

    202 MAILBOX user.xxx.Processed
    217 MAILBOX "user.yyy.Deleted Messages"
    219 MAILBOX "user.zzz.Sent Messages"

all from El Capitan Mac Mail. The sync process collapses most of the duplicates
so the replication is less impacted than the extra work the primary has to do.

Regards,
Ken