Monitor: Elector: share the classic command set if we have a classic mon

The leader now checks to see if any monitors did not provide their
command set, and if so, shares the list of "classic" commands instead
of his own set. This will prevent users from seeing different commands
(depending on whether they connect to an old or new mon) while
performing upgrades, and will make it really obvious if they forgot
to upgrade one of the monitors!

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

diff --git a/src/mon/Elector.cc b/src/mon/Elector.cc
index 625e2bb0bb344d3da5c99909d3a708222edb2633..43b478e99ff3454b0bbf12e1aea9cd1d4ceb0f9c 100644 (file)
--- a/src/mon/Elector.cc
+++ b/src/mon/Elector.cc
@@ -170,7 +170,18 @@ void Elector::victory()
        ++p) {
     quorum.insert(p->first);
     features &= p->second;
-  }    
+  }
+
+  // decide what command set we're supporting
+  bool use_classic_commands = false;
+  for (list<bufferlist>::iterator i = acker_commands.begin();
+      i != acker_commands.end();
+      ++i) {
+    if (i->length() == 0) {
+      use_classic_commands = true;
+      break;
+    }
+  }
   
   cancel_timer();
   
@@ -178,11 +189,21 @@ void Elector::victory()
   bump_epoch(epoch+1);     // is over!
 
   // calculate my supported commands for peons to advertise
-  if (!my_supported_commands.length()) {
-    const MonCommand *cmds;
-    int cmdsize;
+  bufferlist *cmds_bl = NULL;
+  const MonCommand *cmds;
+  int cmdsize;
+  if (!use_classic_commands) {
     get_locally_supported_monitor_commands(&cmds, &cmdsize);
-    MonCommand::encode_array(cmds, cmdsize, my_supported_commands);
+    if(!my_supported_commands.length()) {
+      MonCommand::encode_array(cmds, cmdsize, my_supported_commands);
+    }
+    cmds_bl = &my_supported_commands;
+  } else {
+    get_classic_monitor_commands(&cmds, &cmdsize);
+    if (!classic_commands.length()){
+      MonCommand::encode_array(cmds, cmdsize, classic_commands);
+    }
+    cmds_bl = &classic_commands;
   }
   
   // tell everyone!
@@ -193,12 +214,12 @@ 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;
+    m->commands = *cmds_bl;
     mon->messenger->send_message(m, mon->monmap->get_inst(*p));
   }
     
   // tell monitor
-  mon->win_election(epoch, quorum, features);
+  mon->win_election(epoch, quorum, features, cmds, cmdsize);
 }
 
 

diff --git a/src/mon/Elector.h b/src/mon/Elector.h
index 8efa4d367e347958dea892ef0f983bdff892a421..2b3ce5481e8f3dfc388caa267bdb79d31939f15d 100644 (file)
--- a/src/mon/Elector.h
+++ b/src/mon/Elector.h
@@ -116,6 +116,7 @@ class Elector {
   map<int, uint64_t> acked_me;
   list<bufferlist> acker_commands;
   bufferlist my_supported_commands;
+  bufferlist classic_commands;
   /**
    * @}
    */

diff --git a/src/mon/Monitor.cc b/src/mon/Monitor.cc
index 30c18f4333c56afb2d5aad70a0d1f97b62b158b1..fce9ece87c101d3ceb6651221d8304445bfe59b7 100644 (file)
--- a/src/mon/Monitor.cc
+++ b/src/mon/Monitor.cc
@@ -1489,7 +1489,11 @@ void Monitor::win_standalone_election()
   assert(rank == 0);
   set<int> q;
   q.insert(rank);
-  win_election(1, q, CEPH_FEATURES_ALL);
+
+  const MonCommand *my_cmds;
+  int cmdsize;
+  get_locally_supported_monitor_commands(&my_cmds, &cmdsize);
+  win_election(1, q, CEPH_FEATURES_ALL, my_cmds, cmdsize);
 }
 
 const utime_t& Monitor::get_leader_since() const
@@ -1503,7 +1507,8 @@ epoch_t Monitor::get_epoch()
   return elector.get_epoch();
 }
 
-void Monitor::win_election(epoch_t epoch, set<int>& active, uint64_t features) 
+void Monitor::win_election(epoch_t epoch, set<int>& active, uint64_t features,
+                           const MonCommand *cmdset, int cmdsize)
 {
   dout(10) << __func__ << " epoch " << epoch << " quorum " << active
           << " features " << features << dendl;
@@ -1518,10 +1523,7 @@ 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);
+  set_leader_supported_commands(cmdset, cmdsize);
 
   paxos->leader_init();
   for (vector<PaxosService*>::iterator p = paxos_service.begin(); p != paxos_service.end(); ++p)

diff --git a/src/mon/Monitor.h b/src/mon/Monitor.h
index 347b1fbb4b7e95830fe56ee9ffbada7aa8688756..7cccb9e9ca5ad8f0fdb54735ee1b36d95a06151e 100644 (file)
--- a/src/mon/Monitor.h
+++ b/src/mon/Monitor.h
@@ -527,8 +527,10 @@ public:
   void join_election();
   void start_election();
   void win_standalone_election();
+  // end election (called by Elector)
   void win_election(epoch_t epoch, set<int>& q,
-                   uint64_t features);         // end election (called by Elector)
+                   uint64_t features,
+                   const MonCommand *cmdset, int cmdsize);
   void lose_election(epoch_t epoch, set<int>& q, int l,
                     uint64_t features); // end election (called by Elector)
   void finish_election();