Muting bug 1 times out

[Jonathan Lange]

 * Go to bug 1 <https://bugs.launchpad.net/ubuntu/+bug/1>
 * Click "Mute bug mail"
 * Watch as the throbber throbs
 * Get a timeout

The OOPS associated with this problem is OOPS-1914B944.

The problem appears to be caused by fetching all the indexed messages for Bug 1 (see lib/lp/bug/model/bug.py:524-538) whilst muting, though I'm not clear on why that's getting called at all.

[Graham Binns (gmb)]

A thousand bottoms. And the timeout doesn't come with an OOPS, either,
which is irritating. I shall have to have a dig around in the OOPS
report.

[Robert Collins (lifeless)]

I've linked this to grahams branch and marked it bad-commit: matching the interface is unrelated to the change - but the change will force the parent attribute to None, which is incorrect. The specific callsite involved should be changed, *not* the default for the function.

[Robert Collins (lifeless)]

Further, do we have an oops code for this yet?

[Robert Collins (lifeless)]

Ok, bug 740750 is making this very hard to analyze.

At a guess though:

=== modified file 'lib/lp/bugs/interfaces/bug.py'
--- lib/lp/bugs/interfaces/bug.py 2011-03-29 05:38:15 +0000
+++ lib/lp/bugs/interfaces/bug.py 2011-04-06 19:08:50 +0000
@@ -394,13 +394,14 @@
             readonly=True,
             value_type=Reference(schema=IMessage)))

- indexed_messages = exported(
+ indexed_messages = doNotSnapshot(
+ exported(
         CollectionField(
             title=_("The messages related to this object, in reverse "
                     "order of creation (so newest first)."),
             readonly=True,
             value_type=Reference(schema=IMessage)),
- exported_as='messages')
+ exported_as='messages'))

     def _indexed_messages(include_content=False, include_parents=False):
         """Low level query for getting bug messages.

will fix this

[Robert Collins (lifeless)]

11:34 < _mup_> Bug #744888: Muting bug 1 times out <bad-commit-12754> <story-better-bug-notification> <timeout> <Launchpad itself:Triaged> < https://launchpad.net/bugs/744888 >
11:35 < sinzui> lifeless: I thought Snapshot was taught to always ignore collection fields
11:36 < lifeless> sinzui: Thus I'm asking you :)
11:36 < sinzui> ah, but bugs and questions want to snapshot for the last message I think. Maybe it was not done
11:37 < lifeless> a collection snapshot could just record the tip message (for some apporpriate order)
11:37 < lifeless> and the delta is 'messages newer than X'
11:37 < lifeless> [e.g. see my batch navigator work]

11:50 < lifeless> sinzui: ok so we faded out there
11:50 < lifeless> sinzui: is my suggestion a) broken, b) sensible, c) we need to modify how snapshotting deals with collections ?
11:51 < lifeless> sinzui: or d) none of the above
11:52 < sinzui> lifeless: sorry. I very distracted. IAre we certain that is needed? was it cargo culted from old code?
11:53 < sinzui> as for bug and questions looking at messages, I think that is lazy design. I believe there are two emitters of the modifications and they know if a message was appended
11:53 < lifeless> sinzui: bug one has several thousand messages
11:54 < lifeless> sinzui: I'm certain we either need to not snapshot it, or snapshot it much more efficiently
11:54 < lifeless> sinzui: *and* I'm certain that what is snapshotted internally shouldn't match the API attributes for this object either, as the API has different needs vs in-appserver deltas.
11:55 < sinzui> So the publisher emitting the event should be clear what message was added instead of letting the subscriber guess. I do not think snapshot should be working with deap data
11:55 < sinzui> deep
11:56 < lifeless> sinzui: ok, cool.
11:56 < lifeless> so we doNotSnapshot it, see what breaks, fix the signal to contain the new message if needed
11:57 < sinzui> yep

[Gary Poster (gary)]

No tests fail if you simply make the change that Robert described. That makes me a bit nervous, actually.

That said, I'm not sure what else to check other than clicking around a bit. I'll plan to do a bit more verification that this does what we need, and then land this Monday.

[Launchpad QA Bot (lpqabot)]

Fixed in stable r12829 <http://bazaar.launchpad.net/~launchpad-pqm/launchpad/stable/revision/12829>.

[Robert Collins (lifeless)]

Works on qastaing for wgrant. win.