Re: [openstack-dev] [Nova] - do we need .start and .end notifications in all cases ?

2014-10-16 Thread Matt Riedemann
On 9/25/2014 11:09 AM, Day, Phil wrote: Hi Jay, So just to be clear, are you saying that we should generate 2 notification messages on Rabbit for every DB update? That feels like a big overkill for me. If I follow that login then the current state transition notifications should also be

Re: [openstack-dev] [Nova] - do we need .start and .end notifications in all cases ?

2014-09-25 Thread Day, Phil
Hi Jay, So just to be clear, are you saying that we should generate 2 notification messages on Rabbit for every DB update? That feels like a big overkill for me. If I follow that login then the current state transition notifications should also be changed to Starting to update

Re: [openstack-dev] [Nova] - do we need .start and .end notifications in all cases ?

2014-09-25 Thread Dolph Mathews
On Wed, Sep 24, 2014 at 9:48 AM, Day, Phil philip@hp.com wrote: I think we should aim to /always/ have 3 notifications using a pattern of try: ...notify start... ...do the work... ...notify end... except: ...notify abort...

Re: [openstack-dev] [Nova] - do we need .start and .end notifications in all cases ?

2014-09-24 Thread Day, Phil
I think we should aim to /always/ have 3 notifications using a pattern of try: ...notify start... ...do the work... ...notify end... except: ...notify abort... Precisely my viewpoint as well. Unless we standardize on the above, our

Re: [openstack-dev] [Nova] - do we need .start and .end notifications in all cases ?

2014-09-24 Thread Jay Pipes
On 09/24/2014 09:48 AM, Day, Phil wrote: I think we should aim to /always/ have 3 notifications using a pattern of try: ...notify start... ...do the work... ...notify end... except: ...notify abort... Precisely my viewpoint as well. Unless we standardize on the above, our notifications are

Re: [openstack-dev] [Nova] - do we need .start and .end notifications in all cases ?

2014-09-22 Thread Daniel P. Berrange
On Mon, Sep 22, 2014 at 11:03:02AM +, Day, Phil wrote: Hi Folks, I'd like to get some opinions on the use of pairs of notification messages for simple events. I get that for complex operations on an instance (create, rebuild, etc) a start and end message are useful to help instrument

Re: [openstack-dev] [Nova] - do we need .start and .end notifications in all cases ?

2014-09-22 Thread Day, Phil
Hi Daniel, -Original Message- From: Daniel P. Berrange [mailto:berra...@redhat.com] Sent: 22 September 2014 12:24 To: OpenStack Development Mailing List (not for usage questions) Subject: Re: [openstack-dev] [Nova] - do we need .start and .end notifications in all cases ? On Mon

Re: [openstack-dev] [Nova] - do we need .start and .end notifications in all cases ?

2014-09-22 Thread Sandy Walsh
Hey Phil, (sorry for top-post, web client) There's no firm rule for requiring .start/.end and I think your criteria defines it well. Long running transactions (or multi complex-step transactions). The main motivator behind .start/.end code was .error notifications not getting generated in many

Re: [openstack-dev] [Nova] - do we need .start and .end notifications in all cases ?

2014-09-22 Thread Sandy Walsh
+1, the high-level code should deal with top-level exceptions and generate .error notifications (though it's a little spotty). Ideally we shouldn't need three events for simple operations. The use of .start/.end vs. logging is a bit of a blurry line. At its heart a notification should provide

Re: [openstack-dev] [Nova] - do we need .start and .end notifications in all cases ?

2014-09-22 Thread Jay Pipes
On 09/22/2014 07:24 AM, Daniel P. Berrange wrote: On Mon, Sep 22, 2014 at 11:03:02AM +, Day, Phil wrote: Hi Folks, I'd like to get some opinions on the use of pairs of notification messages for simple events. I get that for complex operations on an instance (create, rebuild, etc) a start

Re: [openstack-dev] [Nova] - do we need .start and .end notifications in all cases ?

2014-09-22 Thread Jay Pipes
On 09/22/2014 07:35 AM, Day, Phil wrote: I'm just a tad worried that this sounds like its starting to use notification as a replacement for logging.If we did this for every CRUD operation on an object don't we risk flooding the notification system. Notifications of this sort aren't a

Re: [openstack-dev] [Nova] - do we need .start and .end notifications in all cases ?

2014-09-22 Thread Jay Pipes
On 09/22/2014 07:37 AM, Sandy Walsh wrote: For some operations like resize, migrate, etc., the .start/.end is good for auditing and billing. Although, we could do a better job by simply managing the launched_at, deleted_at times better. I'm sure I'll get no real disagreement from you or

Re: [openstack-dev] [Nova] - do we need .start and .end notifications in all cases ?

2014-09-22 Thread Jay Lau
Hi Jay, There was actually a discussion about file a blueprint for object notification http://markmail.org/message/ztehzx2wc6dacnk2 But for patch https://review.openstack.org/#/c/107954/ , I'd like we keep it as it is now to resolve the requirement of server group notifications for 3rd party

Re: [openstack-dev] [Nova] - do we need .start and .end notifications in all cases ?

2014-09-22 Thread Sandy Walsh
From: Jay Pipes [jaypi...@gmail.com] Sent: Monday, September 22, 2014 11:51 AM To: openstack-dev@lists.openstack.org Subject: Re: [openstack-dev] [Nova] - do we need .start and .end notifications in all cases ? On 09/22/2014 07:37 AM, Sandy Walsh wrote

Re: [openstack-dev] [Nova] - do we need .start and .end notifications in all cases ?

2014-09-22 Thread Jay Pipes
On 09/22/2014 11:42 AM, Sandy Walsh wrote: Totally agree. Though I would go one step further and say the Task state transitions should be managed by notifications. Then oslo.messaging is reduced to the simple notifications interface (no RPC). Notification follow proper retry semantics and

Re: [openstack-dev] [Nova] - do we need .start and .end notifications in all cases ?

2014-09-22 Thread Jay Pipes
On 09/22/2014 11:22 AM, Jay Lau wrote: Hi Jay, There was actually a discussion about file a blueprint for object notification http://markmail.org/message/ztehzx2wc6dacnk2 But for patch https://review.openstack.org/#/c/107954/ , I'd like we keep it as it is now to resolve the requirement of