Elector: transmit local api on election win, accept leader's on loss

If we're the leader, just point to our local set. Disseminating these
will let peons advertise the full command set supported by the leader.
INCOMPLETE: does not yet handle winning Electors who do not send a command set.

Signed-off-by: Greg Farnum <greg@inktank.com>

diff --git a/src/mon/Elector.cc b/src/mon/Elector.cc
index 1650a997b2d096164838eada56860ae756058944..9b32649733fc48a32ebf137f74712dcf103c297c 100644 (file)
--- a/src/mon/Elector.cc
+++ b/src/mon/Elector.cc
@@ -165,8 +165,16 @@ void Elector::victory()
   
   assert(epoch % 2 == 1);  // election
   bump_epoch(epoch+1);     // is over!
+
+  // calculate my supported commands for peons to advertise
+  if (!my_supported_commands.length()) {
+    const MonCommand *cmds;
+    int cmdsize;
+    get_locally_supported_monitor_commands(&cmds, &cmdsize);
+    MonCommand::encode_array(cmds, cmdsize, my_supported_commands);
+  }
   
-  // tell everyone
+  // tell everyone!
   for (set<int>::iterator p = quorum.begin();
        p != quorum.end();
        ++p) {
@@ -174,6 +182,7 @@ void Elector::victory()
     MMonElection *m = new MMonElection(MMonElection::OP_VICTORY, epoch, mon->monmap);
     m->quorum = quorum;
     m->quorum_features = features;
+    m->commands = my_supported_commands;
     mon->messenger->send_message(m, mon->monmap->get_inst(*p));
   }
     
@@ -292,7 +301,19 @@ void Elector::handle_victory(MMonElection *m)
   mon->lose_election(epoch, m->quorum, from, m->quorum_features);
   
   // cancel my timer
-  cancel_timer();      
+  cancel_timer();
+
+  // stash leader's commands
+  if (m->commands.length()) {
+    MonCommand *new_cmds;
+    int cmdsize;
+    bufferlist::iterator bi = m->commands.begin();
+    MonCommand::decode_array(&new_cmds, &cmdsize, bi);
+    set_leader_supported_commands(new_cmds, cmdsize);
+  } else { // they are a legacy monitor; use known legacy command set
+    // TODO: actually store legacy command set, and use here!
+  }
+
   m->put();
 }
 

diff --git a/src/mon/Elector.h b/src/mon/Elector.h
index f1f19b49becfb5d90125b797727db4bb8f3a5197..d17429ffa78f913188827049d841791d607b5c5d 100644 (file)
--- a/src/mon/Elector.h
+++ b/src/mon/Elector.h
@@ -114,6 +114,7 @@ class Elector {
    * victory.  Also note each peer's feature set.
    */
   map<int, uint64_t> acked_me;
+  bufferlist my_supported_commands;
   /**
    * @}
    */

diff --git a/src/mon/Monitor.cc b/src/mon/Monitor.cc
index ebdbd012d1a81c54384cecbfef82c55d78608db4..9c7a99fe5a3c4c57018a76c59f6884508a0772b3 100644 (file)
--- a/src/mon/Monitor.cc
+++ b/src/mon/Monitor.cc
@@ -1518,6 +1518,11 @@ void Monitor::win_election(epoch_t epoch, set<int>& active, uint64_t features)
   clog.info() << "mon." << name << "@" << rank
                << " won leader election with quorum " << quorum << "\n";
 
+  const MonCommand *new_cmds;
+  int cmdsize;
+  get_locally_supported_monitor_commands(&new_cmds, &cmdsize);
+  set_leader_supported_commands(new_cmds, cmdsize);
+
   paxos->leader_init();
   for (vector<PaxosService*>::iterator p = paxos_service.begin(); p != paxos_service.end(); ++p)
     (*p)->election_finished();