connect to mongodb with pymongo's mongo_client

[aric]

I would like to see celiometer implement pymongos mongo_client as this is the correct way to have H/A for the mongodb backend.

"PyMongo ... highly available ... whether you use a single replica set or a large sharded cluster.

class pymongo.mongo_client.MongoClient ->

"The resultant client object has connection-pooling built in. It also performs auto-reconnection when necessary. If an operation fails because of a connection error, ConnectionFailure is raised. If auto-reconnection will be performed, AutoReconnect will be raised. Application code should handle this exception (recognizing that the operation failed) and then continue to execute."

relevant links:
http://api.mongodb.org/python/current/api/pymongo/mongo_client.html#module-pymongo.mongo_client
http://api.mongodb.org/python/current/examples/high_availability.html

[xingzhou (xingzhou)]

Considered as a new feature to Ceilometer

[xingzhou (xingzhou)]

pymongo.Connection also provides a replicaSet param to identify the replication set name, this method seems will make the minimum change in code

[Julien Danjou (jdanjou)]

xingzhou, are you going to provide a patch for this or should someone else take this bug over?

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: master
Review: https://review.openstack.org/34157

[xingzhou (xingzhou)]

@jd___, sorry for the delay, I had some network trouble last week to connect to gerrit, I submitted a patch today, fyi

[François Charlier (francois-charlier)]

@xingzhou, as you may see in the review, I had been working on this feature as well, you can see my work rebased on your patch here: https://github.com/fcharlier/ceilometer/tree/review/xingzhou/bug/1188649

Feel free to ping me (fc__) on IRC !

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/34157
Committed: http://github.com/openstack/ceilometer/commit/a2b6dc4ed2b03972b53c278b0d23ba03e84565b0
Submitter: Jenkins
Branch: master

commit a2b6dc4ed2b03972b53c278b0d23ba03e84565b0
Author: xingzhou <email address hidden>
Date: Thu Jun 20 04:37:58 2013 -0400

    Enable Ceilometer to support mongodb replication set

    At present, ceilometer does not support mongodb replication set.
    As a result, when the primary mongod node is down, ceilometer can
    not write or read meters.

    Use pymongo.Connection object's replicaSet param and allowing to connect
    with a host seed list will let the mongodb connection support replication set.

    Change-Id: I8404ca5b08b6e73366161c07b3815f75bed7e0eb
    Fixes: Bug 1188649