Re: GitLab AMA Topic: Message Bus
On Tue, 2020-11-24 at 14:57 +0100, Clement Verna wrote:
On Mon, 23 Nov 2020 at 21:31, Adam Williamson <
adamwill(a)fedoraproject.org> wrote:
> On Mon, 2020-11-23 at 15:11 -0500, Neal Gompa wrote:
> > >
> > > I would highly recommend not creating message consumers that
> rely on
> > > any particular message ordering because they're not going to
> work
> > > properly, GitLab or not.
> >
> > Too late, pretty much every consumer I'm aware of relies on
> having
> > chronological order or at least some way to sort them
> chronologically
> > for processing for messages.
>
> I don't think any consumer I've written does. They all just work on
> the
> basis "a thing happened; do some things relevant to the thing that
> happened".
>
Honestly my feeling is that most of our consumers fall into that
category , I can't think of a use case where the chronological order
matters (I have been told CI might, but I don't know the exact use
case).
If anyone has a concrete example, I would welcome it very much so
that we can use it as a test case with GitLab.
Well CI needs to be told it can't whatever the use case because
chronological ordering of messages isn't a guarantee and it'll break if
that's assumed. That's true of any consumer now, so if Neal is aware of
any that fall into that category (I'm not) they should be fixed. It's
not a safe assumption with AMQP and it wasn't a safe assumption with
ZeroMQ either.