From ef425374250014393c1d432a3eda95179bb70537 Mon Sep 17 00:00:00 2001 From: Sage Weil Date: Tue, 8 Aug 2017 18:43:22 -0400 Subject: [PATCH] mon/Elector: force election epoch bump on start 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 --- src/mon/Elector.cc | 14 ++++++++++++-- 1 file changed, 12 insertions(+), 2 deletions(-) diff --git a/src/mon/Elector.cc b/src/mon/Elector.cc index 001fea95f3d5..b7fde85528de 100644 --- a/src/mon/Elector.cc +++ b/src/mon/Elector.cc @@ -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()); + 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() -- 2.47.3