Public bug reported:
When upgrading a ceph cluster, the charm code orders the nodes and
starts performing upgrades a single node at a time. The charms make use
of ceph's ability to provide an arbitrary key/value store in the monitor
and will mark the progress of the upgrades in this key storage.
This allows nodes to watch this central storage for progress of the
upgrade. As a node begins its upgrade path, it stores its start time
(via time.time()) in the ceph monitor's key value storage. The node
which is to upgrade after the current node will read the value stored in
the key and compare it to a timestamp from 10 minutes ago in order to
determine if the previous node should be considered timed out or not.
The problem is that the value read in from reading the monitor's key is
stored and returned as a string and then compared to a floating point
value from the time.time() call. This results in the node never timing
out the previous node.
This is however, a good thing. In the current released form of the
charms (16.10), the upgrade path will always recursively chown the OSD
directories, which in a production cluster is unlikely to finish in 10
minutes. Since the ceph charms will stop all services on the cluster at
the same time, this would effectively lead to an entire cluster outage
if the code were to work correctly.
Instead of fixing this code to add a timeout, I propose the timeout
logic be removed completely and error conditions be revisited in order
to prevent a sweeping cluster outage.
** Affects: charms.ceph
Importance: Medium
Status: Triaged
** Affects: ceph (Juju Charms Collection)
Importance: Undecided
Status: New
** Affects: ceph-mon (Juju Charms Collection)
Importance: Undecided
Status: New
** Affects: ceph-osd (Juju Charms Collection)
Importance: Undecided
Status: New
** Tags: sts
** Also affects: ceph-osd (Juju Charms Collection)
Importance: Undecided
Status: New
** Also affects: ceph (Ubuntu)
Importance: Undecided
Status: New
** No longer affects: ceph (Ubuntu)
** Also affects: ceph-mon (Juju Charms Collection)
Importance: Undecided
Status: New
** Also affects: ceph (Juju Charms Collection)
Importance: Undecided
Status: New
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https://bugs.launchpad.net/bugs/1664435
Title:
Upgrade timeout logic is faulty
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