mon: discover mon addrs, names during election state too

Currently we only detect new mon addrs and names during the probing phase.
For non-trivial clusters, this means we can get into a sticky spot when
we discover enough peers to form an quorum, but not all of them, and the
undiscovered ones are enough to break the mon ranks and prevent an
election.

One way to work around this is to continue addr and name discovery during
the election.  We should also consider making the ranks less sensitive to
the undefined addrs; that is a separate change.

Fixes: #4924
Backport: dumpling
Signed-off-by: Sage Weil <sage@inktank.com>
Tested-by: Bernhard Glomm <bernhard.glomm@ecologic.eu>

diff --git a/src/mon/Monitor.cc b/src/mon/Monitor.cc
index 45ca02027fc9632cec73511d5c21d398fe69355b..10f5bfb149c72547a805c5ad0c8791b53d417a26 100644 (file)
--- a/src/mon/Monitor.cc
+++ b/src/mon/Monitor.cc
@@ -1292,7 +1292,8 @@ void Monitor::handle_probe_reply(MMonProbe *m)
   dout(10) << "handle_probe_reply " << m->get_source_inst() << *m << dendl;
   dout(10) << " monmap is " << *monmap << dendl;
 
-  if (!is_probing()) {
+  // discover name and addrs during probing or electing states.
+  if (!is_probing() && !is_electing()) {
     m->put();
     return;
   }
@@ -1326,6 +1327,12 @@ void Monitor::handle_probe_reply(MMonProbe *m)
             << peer_name << " -> " << m->name << " in my monmap"
             << dendl;
     monmap->rename(peer_name, m->name);
+
+    if (is_electing()) {
+      m->put();
+      bootstrap();
+      return;
+    }
   } else {
     dout(10) << " peer name is " << peer_name << dendl;
   }
@@ -1342,6 +1349,12 @@ void Monitor::handle_probe_reply(MMonProbe *m)
     }
   }
 
+  // end discover phase
+  if (!is_probing()) {
+    m->put();
+    return;
+  }
+
   assert(paxos != NULL);
 
   if (is_synchronizing()) {