Upgrade to cyrus-imapd and connection drops when searching mailboxes

[Michael Menge]

Hi,

Quoting "James B. Byrne via Info-cyrus" <info-cyrus at lists.andrew.cmu.edu>:

> cyrus-imapd30-3.0.8_2
> Name           : cyrus-imapd30
> Version        : 3.0.8_2
> Installed on   : Tue Jan  8 11:07:34 2019 EST
> Origin         : mail/cyrus-imapd30
> Architecture   : FreeBSD:11:amd64
> Prefix         : /usr/local
> Categories     : ipv6 mail
> Licenses       : BSD4CLAUSE
> Maintainer     : ume at FreeBSD.org
>
> Since upgrading to this version from 3.0.8_1 on January 8 we have seen
> a considerable increase of messages in the maillog that look similar
> to this:
>
> CYRUS/lmtpunix[79768]: mailbox: longlock user.name.delivery for 1.4
> seconds
>
> Where the number of seconds varies between 1.x and 11.x.  When I say
> considerably I mean from between 10 and 30 per log rollover to over
> 800 today and it is not yet noon.
>
> Perhaps coincidently, users are reporting imap connections dropping
> when they are performing text searches on their mailboxes.  The user
> mail client being squirrelmail.
>

have you configured a search engine? and have you enabled the conversation db.
Xapian and Squatter seam to require enabled conversation db to use the
search index. At least for squatter there is even a performance regression
for TEXT search even if conversation db is enabled
(https://github.com/cyrusimap/cyrus-imapd/issues/2598)


> Are the longlock reports and the imap connection drop related?
>
An cyrus processes tires to gain access to the mailbox while an
other process is still accessing it. If this takes to long the client
might disconnect. You can try telemetry logging to discover what is
happening .


> If imap drops a connection is the reason for that event logged?  Can
> it be logged?
>
The question is which side drops the connection the cyrus-imapd process
or the imap client (squirrelmail)? tcpdum and telemetry logging might
reveal the answer.

What timeout is configured in squirrelmail?



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