Messages _list is not using the right index

[Flavio Percoco]

mongodb's message controller is not using the right index. This can be fix by using hint and passing all indexed fields to the query:

db.messages.find({ "q" : ObjectId("51f280de5e9e4e84eb7eb63d") , "e" : { "$gt" : ISODate("2013-07-29T13:02:29.536Z")}, "c.e" : { "$lte" : ISODate("2013-07-29T13:02:29.536Z")}}).sort({"_id": -1}).explain()

{
        "cursor" : "BtreeCursor claimed",
..................................

The above query should be using the "active" index instead and the marker should always be passed. We can use {"$gt": 0} (or {"$ne": null} ) when it is not needed.

As for the index, we should use hint and tell the query what index to use.

https://github.com/stackforge/marconi/blob/master/marconi/storage/mongodb/messages.py#L76 (Index to hit)

https://github.com/stackforge/marconi/blob/master/marconi/storage/mongodb/messages.py#L267 (marker)

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: master
Review: https://review.openstack.org/39456

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/39456
Committed: http://github.com/stackforge/marconi/commit/3d6224a58a82769a14dfb85d0290e170da8a4094
Submitter: Jenkins
Branch: master

commit 3d6224a58a82769a14dfb85d0290e170da8a4094
Author: Flaper Fesp <email address hidden>
Date: Wed Jul 31 13:04:24 2013 +0200

    Tell _list queries what index to use

    This patch adds hint to all _list queries telling them to use the
    'active' index. This can be overriden by the caller of _list but that,
    most likely, won't be necessary. All callers of _list care about getting
    active messages and provide the parameters necessary for that.

    Fixes bug: #1206128

    Change-Id: Ifbe48711825cadd81ebbd5dd07bc9da8a88975fa