RepoMirrors/ceph
1
0
Fork 0
mirror of https://github.com/ceph/ceph synced 2025-02-22 10:37:15 +00:00
Code Issues Packages Projects Releases Wiki Activity

mon/Elector: force election epoch bump on start

Browse Source 
We are generally careful when bumping the epoch so that we can join
existing rounds.  However, if we restart in the middle of an election,
and change versions, we need to be certain that our previous ACK (as
$version - 1) isn't accepted as truth for the restarted daemon (running
$version) keeping the same epoch.

The conservatism with bumping is to avoid spurious election cycles, but
mon restarts are more rare, and we need them here.

Fixes: http://tracker.ceph.com/issues/20949
Signed-off-by: Sage Weil <sage@redhat.com>
This commit is contained in:
Sage Weil 2017-08-08 18:43:22 -04:00
parent b61be07d45
commit ef42537425
1 changed files with 12 additions and 2 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

14
src/mon/Elector.cc
View File

@ -35,9 +35,19 @@ static ostream& _prefix(std::ostream *_dout, Monitor *mon, epoch_t epoch) {
void Elector::init()
{
epoch = mon->store->get(Monitor::MONITOR_NAME, "election_epoch");
if (!epoch)
if (!epoch) {
dout(1) << "init, first boot, initializing epoch at 1 " << dendl;
epoch = 1;
dout(1) << "init, last seen epoch " << epoch << dendl;
} else if (epoch % 2) {
dout(1) << "init, last seen epoch " << epoch
<< ", mid-election, bumping" << dendl;
++epoch;
auto t(std::make_shared<MonitorDBStore::Transaction>());
t->put(Monitor::MONITOR_NAME, "election_epoch", epoch);
mon->store->apply_transaction(t);
} else {
dout(1) << "init, last seen epoch " << epoch << dendl;
}
}
void Elector::shutdown()