Roman Dobosz wrote:
On Tue, 17 May 2016 21:41:11 -0700
Joshua Harlow<harlo...@fastmail.com> wrote:
Options I see:
Constrain oslo.messaging in global-requirements.txt for
stable/mitaka with 4.6.1. Hard to do since it requires wide
cross-project coordination.
Remove that hack in stable/mitaka as we did with master. It may
be bad because this was wanted very much by some of the users
Not sure what else we can do.
You could set up your test jobs to use the upper-constraints.txt
file in
the requirements repo.
What was the outcome of the discussion about adding the
at-least-once
semantics to oslo.messaging?
So there are a few options I am seeing so far (there might be more
that I don't see also), others can hopefully correct me if they are
wrong (which they might be) ;)
Option #1
Oslo.messaging (and the dispatcher part that does this) stays as is,
doing at-most-once for RPC (notifications are in a different
category here so let's not discuss them) and doing at-most-once well
and battle-hardened (it's current goal) across the various backend
drivers it supports.
At that point at-least-once will have to done via some other library
where this kind of semantics can be placed, that might be tooz via
https://review.openstack.org/#/c/260246/ (which has similar
semantics, but is not based on a kind of RPC, instead it's more like
a job-queue).
Option #2
Oslo.messaging (and the dispatcher part that does this) changes
(possibly allowing it to be replaced with a different type of
dispatcher, ie like in https://review.openstack.org/#/c/314732/);
the default class continues being great at for RPC (notifications
are in a different category here so let's not discuss them) and
doing at-most-once well and battle-hardened (it's current goal)
across the various backend drivers it supports. If people want to
provide an alternate class with different semantics they are
somewhat on there own (but at least they can do this).
Issues raised: this though may not be wanted, as some of the
oslo.messaging folks do not want the dispatcher class to be exposed
at all (and would prefer to make it totally private, so exposing it
would be against that goal); though people are already 'hacking'
this kind of functionality in, so it might be the best we can get at
the current time?
Option #3
Do nothing.
Issues raised: everytime oslo.messaging changes this *mostly*
internal dispatcher API a project will have to make a new 'hack' to
replace it and hope that the semantics that it has 'hacked' in will
continue to be compatible with the various drivers in
oslo.messaging. Not IMHO a sustainable way to keep on working (and
I'd be wary of doing this in a project if I was the owner of one,
because it's ummm, 'dirty').
My thoughts on what could work:
What I'd personally like to see is a mix of option #1 and #2, where
we have commitment from folks (besides myself, lol) to work on
option #1 and we temporarily move forward with option #2 with a
strict-statement that the functionality we would be enabling will
only exist for say a single release (and then it will be removed).
Thoughts from others?
Option #4
(Which might be obvious) Directly use RabbitMQ driver, like
pika/kombu, which can expose all the message queue features to the
project.
Issues raised: Pushback from the community due not using
oslo.messaging and potential necessity for implementing it for other
drivers/transports, or forcing to use particular message queue/driver
in every project.
Isn't this similar/same as to option #1? Nothing about option #1 says
(from my understanding) that it must be implemented via oslo.messaging
(and in all likely-hood it can't be).
__________________________________________________________________________
OpenStack Development Mailing List (not for usage questions)
Unsubscribe: openstack-dev-requ...@lists.openstack.org?subject:unsubscribe
http://lists.openstack.org/cgi-bin/mailman/listinfo/openstack-dev
