[MM3-users] Re: moving from sqlite3 to postgresql

Stephen J. Turnbull <steve@turnbull.jp> wrote: >> I installed via debian packages, and I'd really prefer to stay with that. >> (Not what many maintainers would say, I know. Essential that it work if >> mailman3 is going to take over)

> That's really Debian's problem, and it's a hard one since the whole
> point of using Debian packages for mission-critical applications is
> that they're stable.  Unfortunately, the email and web environments
> are not, and dealing with changes in them is often quite impractical
> given the Debian release cycle.

Yes, I'm aware of this tusscle. There are some ways to split this up.

>> I installed with sqlite3, since it seemed if all work was going to
>> go through the mailman3 daemon, that it would handle all the
>> concurrency issues.

> The problem is that sqlite3 is intended to be a single-threaded
> system, but Mailman 3 by default spawns around 15 daemons that may try
> to access the database.  I would expect you would have warnings that
> the database is locked frequently.  Not sure what you mean by
> "Sometimes this goes way on it's own, but sometimes it does not".

Meaning, sometimes whatever has the lock releases it everything proceeds. Sometimes, it's still stuck a few days later, and I restart the mailman daemons.

> Note that our primary purpose for the sqlite3 configuration is so unit
> tests don't have to spin up a full-scale PostgreSQL or MySQL database.

Fair enough. It was not obvious when installing that I should not use sqlite3.

>> So I tried to switch last week from sqlite3 to postgresql.
>> I used pgloader with a configuration file attached below.

> Can't help you with that offhand, never used pgloader.  Whatever
> method you use to load up the pg database, I would recommend doing
> some psql cave-diving into the PostgreSQL database to confirm it's
> sane before trying to configure Mailman to use that database.

Yes, I'm gonna have to do that. At least I'll start by counting number of records in each table, and then see if there is some systematic lack.

>> ps: I'd pay some $$ money for email support consulting.

> See https://wiki.list.org/COM/Mailman%20consulting%20services

> Per my .sig, I'm on the list above but please go through channels
> linked there rather than talking to me personally about business.

Understood.