Comment 4 for bug 1388778

Reviewed: https://review.openstack.org/137682
Committed: https://git.openstack.org/cgit/openstack/ceilometer/commit/?id=638c66c889caef65873a9c4df5760583ad29ce3a
Submitter: Jenkins
Branch: stable/juno

commit 638c66c889caef65873a9c4df5760583ad29ce3a
Author: ZhiQiang Fan <email address hidden>
Date: Mon Nov 3 20:57:04 2014 +0800

    Add timeout to all http requests

    Currently, we generate lots of samples by polling data from other services,
    but theses rest requests have no timeout limitation. We have observed that
    some requests (for example, keystone due to openssl problem) may stuck for
    over several days (maybe forever if we don't restart the service). Other
    pollsters in same thread will not be able to work too. The worst thing is
    that, when outside (keystone) service becomes normal, Ceilometer cannot
    recover itself automatically, cloud operator needs to restart it manually.

    So I strongly suggest that we should add timeout limit to **every** rest api
    call, this is quite important to improve Ceilometer's robust and reliability.

    This patch adds a new option named http_timeout, and applies it to almost
    all http requests in Ceilometer project.

    Change-Id: I76df2c0a9ffacb252e15edbb125e37ccb2aac4aa
    Closes-Bug: #1388778
    (cherry picked from commit bd0244ffe63b752649ae74f65a46563e986dcb00)