mon: tell MonmapMonitor first about winning an election

It is important in the bootstrap case that the very first paxos round
also codify the contents of the monmap itself in order to avoid any manner
of confusing scenarios where subsequent elections are called and people
try to recover and modify paxos without agreeing on who the quorum
participants are.

Signed-off-by: Sage Weil <sage@inktank.com>
(cherry picked from commit ad7f5dd481a7f45dfe6b50d27ad45abc40950510)

diff --git a/src/mon/Monitor.cc b/src/mon/Monitor.cc
index f29af78fd6f24de8ddb3d8310ac2cac6cbf332b6..f469a174705fc162a611d1b5e34d65ffef0da567 100644 (file)
--- a/src/mon/Monitor.cc
+++ b/src/mon/Monitor.cc
@@ -1503,8 +1503,17 @@ void Monitor::win_election(epoch_t epoch, set<int>& active, uint64_t features)
                << " won leader election with quorum " << quorum << "\n";
 
   paxos->leader_init();
-  for (vector<PaxosService*>::iterator p = paxos_service.begin(); p != paxos_service.end(); ++p)
-    (*p)->election_finished();
+  // NOTE: tell monmap monitor first.  This is important for the
+  // bootstrap case to ensure that the very first paxos proposal
+  // codifies the monmap.  Otherwise any manner of chaos can ensue
+  // when monitors are call elections or participating in a paxos
+  // round without agreeing on who the participants are.
+  monmon()->election_finished();
+  for (vector<PaxosService*>::iterator p = paxos_service.begin();
+       p != paxos_service.end(); ++p) {
+    if (*p != monmon())
+      (*p)->election_finished();
+  }
   health_monitor->start(epoch);
 
   finish_election();