Investigate repoze.mailin sqlite locks

[Paul Everitt]

We're still getting plagued with SQLite table locks on kdiab. We had a brief discussion with Tres identifying some things to look at.

From Email
==========

The following is the email exchange:

Paul Everitt wrote:
> Hi there. We're a bit wedged on repoze.mailin and the sqlite locks,
> no pun intended.
>
> This morning I checked to see why Will said mailin didn't work during
> tested. The database was locked. It was last locked the morning he
> started testing.
>
> The challenge is that we don't know what the problem is, and can't
> reproduce the problem. However, that puts us in a "do nothing" mode
> that won't really be acceptable.
>
> We could simply *guess* and say daemon-izing it would work. It's
> better than the status quo.

Is the current implementation running as a "one shot" from cron? If so,
we should do two things:

- - Ensure that the cron script uses a well-known dance to keep from
 re-running the process if it is already running.

Doesn't currently do this, but...

- - Figure out if / why it is running so long.

I've never seen any evidence that it takes more than a few seconds to run. (Although there might be anecdotal field evidence that I haven't seen yet.)

- - If it is *not* running long, add some exception handling code
 which ensures that the lock gets released even on some failure
 case (which ought to be logged somewhere).

I implemented this in my first round of trouble shooting this a while back, although it's certainly worth an extra look to see if there's a leak somewhere.

Chris

[Paul Everitt (paul-agendaless)]

Shane, if you could also take this one. ChrisR knows the most about it, but I need to get him to work on migration. It appears you won't be starting on the unit tests for karl.peopledir today, so you have a bit of a gap in tickets.

[Paul Everitt (paul-agendaless)]

Tres said he would pick this one up.

[Paul Everitt (paul-agendaless)]

Rolling over to M13.

[Tres Seaver (tseaver)]

Please upload a copy of the crontab for the user running the
mail-in processing, and reassign to me.

[LarsN (lars-sixfeetup)]

The current crontab for user "zope" is

*1 * * * * /var/db/karl3/cronscripts/cron-send-alerts.sh >> /var/db/karl3/log/outgoing_mail.log 2>&1
*1 * * * * /var/db/karl3/cronscripts/cron-process-mail.sh >> /var/db/karl3/log/incoming_mail.log 2>&1

[Tres Seaver (tseaver)]

-----BEGIN PGP SIGNED MESSAGE-----
Hash: SHA1

Tres Seaver wrote:
> Please upload a copy of the crontab for the user running the
> mail-in processing, and reassign to me.
>
> ** Changed in: karl3
> Assignee: Tres Seaver (tseaver) => LarsN (lars-sixfeetup)
>

Looks like I need to see as much of the log file as possible:

  /var/db/karl3/log/incoming_mail.log

Can you upload that file, plus any rotated older versions still around?

Tres.
- --
===================================================================
Tres Seaver [phone] <email address hidden>
Palladion Software "Excellence by Design" http://palladion.com
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[Tres Seaver (tseaver)]

Also, I need to see how the script is wired:

  /var/db/karl3/cronscripts/cron-process-mail.sh

[Tres Seaver (tseaver)]

repoze.mailin 0.1.4, now released to the lemonade-dev index, contains a fix
which should resolve this problem.