mirror of
https://git.proxmox.com/git/mirror_corosync
synced 2026-01-21 04:27:53 +00:00
cb5fd77501
qdevice is a very special node in the cluster and it adds a certain
amount of complexity and special cases across the code.
most of the qdevice data are shared across the cluster (name/votes)
but effectively each node has a different view of the qdevice
(registered/unregistered/voting/etc.)
with this change, we align the qdevice view across the node,
exchanging more data between nodes and we fix how qdevice behaves
and it is configured.
The only side effect is that the amount of data transmitted on wire
is slightly higher.
The qdevice API is still disabled by default. This means that
the amount of real changes in current code are a lot smaller
than it appears by this patch.
TODO: documentation/man pages needs to be updated once
this change is in (and behavior finalized).
User visible changes:
- configuration (coroparse, exec/votequorum):
the quorum device section is now standalone within the quorum.
quorum {
provider: corosync_votequorum
device {
model: (name)
timeout: (millisec)
votes:
}
}
the keyword "model:" is mandatory to enable qdevice in configuration
and should express the name of the script/daemon that will provide
the qdevice. Looking into the future, an init script or systemd
service will look for that name in /path/to/be/decided/name
and start/stop qdevice.
timeout: defines the maximum interval the qdevice implementation
has available between poll (see votequorum_qdevice_poll.3) before
the device is considered dead and votes discarded
votes: is now a configuration parameter and not an API call.
quorum devices don't care what they need to vote.
votes is autocalculated when a nodelist is available and all
nodes in the list vote 1. Otherwise this parameter is mandatory.
- configuration (exec/votequorum):
startup and runtime configuration changes have been improved.
errors at startup are considered fatal. errors at runtime
have different exit paths.
startup:
* quorum.two_node and qdevice are incompatible.
* quorum.expected_votes requires quorum.device.votes.
* quorum.expected_votes - quorum.device.votes cannot be lower
than 2.
* qdevice and last_man_standing are mutually exclusive.
* qdevice and auto_tie_breaker are mutually exclusive.
runtime config changes:
* quorum.two_node and qdevice are incompatible:
if quorum device is alive, two_node is disabled.
if quorum device is not alive and node count is 2, two_node is
enabled, and quorum device cannot be registered
* if either last_man_standing or auto_tie_breaker were enabled
at startup, and at runtime quorum device is configured,
quorum device registration will be blocked.
* if quorum.expected_votes is configured but not quorum.device.votes,
quorum device registration will be blocked.
* if quorum.device.votes is not configured and we cannot
automatically calculate it, quorum device registration will be blocked.
* An error in configuring quorum.expected_votes and quorum.device.votes
will block quorum device registration.
blocking quorum device registation, also means dropping the votes.
quorum.device.votes (either set or automatically calculated) is now
used to determine current expected_votes in the cluster.
- logging (exec/votequorum):
all errors from configuration are treated as WARNING/CRITICAL.
lots of extra DEBUG output is added (see internal changes too).
- corosync-quorumtool (tools/corosync-quorumtool):
* added option to forcefully kick out a quorum device from the local
node. This is for emergency recovery only and it is only
available when qdevice API is built-in.
* Improved status output, specifically add node state and qdevice
information
[root@fedora-master-node2 coro]# corosync-quorumtool -s
Version: 1.99.4.12-9c7d-dirty
Quorum type: corosync_votequorum
Nodes: 2
Ring ID: 132
Quorate: Yes
Node votes: 1
Node state: Member
Expected votes: 3
Highest expected: 3
Total votes: 3
Quorum: 2
Flags: Quorate Qdevice
Nodeid Votes Name
1 1 fedora-master-node1.int.fabbione.net
2 1 fedora-master-node2.int.fabbione.net
0 1 QDEVICE (Voting)
* allow to print status for any node in the cluster known to
local node.
[root@fedora-master-node1 coro]# corosync-quorumtool -s
Version: 1.99.4.12-9c7d-dirty
Quorum type: corosync_votequorum
Nodes: 2
Ring ID: 144
Quorate: Yes
Node votes: 1
Node state: Member
Expected votes: 3
Highest expected: 3
Total votes: 2
Quorum: 2
Flags: Quorate
Nodeid Votes Name
1 1 fedora-master-node1.int.fabbione.net
2 1 fedora-master-node2.int.fabbione.net
[root@fedora-master-node1 coro]# corosync-quorumtool -s -n 2
Version: 1.99.4.12-9c7d-dirty
Quorum type: corosync_votequorum
Nodes: 2
Ring ID: 144
Quorate: Yes
Node votes: 1
Node state: Member
Expected votes: 3
Highest expected: 3
Total votes: 3
Quorum: 2
Flags: Quorate Qdevice
Nodeid Votes Name
1 1 fedora-master-node1.int.fabbione.net
2 1 fedora-master-node2.int.fabbione.net
0 1 QDEVICE (Voting)
Internal changes:
- change qdevice timer to not run all time, but only when necessary.
- change votequorum_nodeinfo on wire data to use flags instead of uint8_t
and add QDEVICE status.
- allocate nodeid 0 to qdevice since it's the only real
nodeid that be reserved.
- change send_nodeinfo to allow to send nodeinfo for any node
so that we can share qdevice info across the cluster
(and this might be useful in future if we need to sync
internal cluster view).
- add votequorum api call to update qdevice name
- add runtime data if quorum device has been forcefully disabled
by config error
- add qdevice votes to expected_votes calculation (this
is probably the biggest difference vs cman)
- change votequorum_read_nodelist_configuration so that
we can autocalculate votes for qdevice (we need the nodecount
vs votes).
- add all checks for startup/runtime config (see above).
- do not make qdevice part of the membership_list received from
totem. None of our users care about it and it is not a real node.
- change onwire message handlers to deal with "data for this node from any node"
case and undersand nodeid 0 for qdevice info
- always allocate qdevice at startup. this simplifies code a lot.
- dispatch qdevice nodeinfo on membership changes.
- inform libvotequorum users when a qdevice is registered
- improve substantially qdevice api and add a simple
barrier based on qdevice name.
- add qdevice API barrier at cluster level. This feature allow
only one qdevice name to be active in the cluster at any time.
- qdevice getinfo can now report status for qdevice on any node.
- change slightly the way the qdevice API is built-in/out:
only the libvotequorum calls are #ifdef'out now. Doing so in
the core is too complex and would make the code unreadable
with the risk of missing a bit or two effectively introducing
an on-wire incompatibility if we will ever turn the API on.
- probably added some bugs on the way...
TODO: update qdevice_* API once the above is settled and test
qdevice integration with other features.
Signed-off-by: Fabio M. Di Nitto <fdinitto@redhat.com>
Reviewed-by: Christine Caulfield <ccaulfie@redhat.com>
Reviewed-by: Steven Dake <sdake@redhat.com> (only second part)
|
||
|---|---|---|
| .. | ||
| scripts | ||
| .gitignore | ||
| cpgbench.c | ||
| cpgbenchzc.c | ||
| cpgbound.c | ||
| cpgverify.c | ||
| evsbench.c | ||
| evsverify.c | ||
| Makefile.am | ||
| stress_cpgcontext.c | ||
| stress_cpgfdget.c | ||
| stress_cpgzc.c | ||
| testcpg2.c | ||
| testcpg.c | ||
| testcpgzc.c | ||
| testevs.c | ||
| testevsth.c | ||
| testmake.sh | ||
| testparse.c | ||
| testquorum.c | ||
| testsam.c | ||
| testtimer.c | ||
| testvotequorum1.c | ||
| testvotequorum2.c | ||
| testzcgc.c | ||