mon: keep pgmap consistent

We were cutting corners and updating the live map before it
committed to paxos, since pg stats aren't system critical.  This
can lead to problems due to the way "latest" is saved out, though,
and it can be confusing to see things jump backward in time.

diff --git a/src/mon/PGMonitor.cc b/src/mon/PGMonitor.cc
index c8d704887d7207379f9b419f580e499e45a90a36..1fd102c3b2f6ce558c4da656ff22b69133de9d70 100644 (file)
--- a/src/mon/PGMonitor.cc
+++ b/src/mon/PGMonitor.cc
@@ -322,15 +322,22 @@ bool PGMonitor::prepare_pg_stats(MPGStats *stats)
   // osd stat
   pending_inc.osd_stat_updates[from] = stats->osd_stat;
   
-  // apply to live map too (screw consistency)
-  if (pg_map.osd_stat.count(from)) {
+  if (pg_map.osd_stat.count(from))
     dout(10) << " got osd" << from << " " << stats->osd_stat << " (was " << pg_map.osd_stat[from] << ")" << dendl;
-    pg_map.stat_osd_sub(pg_map.osd_stat[from]);
-  } else {
+  else
     dout(10) << " got osd " << from << " " << stats->osd_stat << " (first report)" << dendl;
-  }
+
+  // apply to live map too (screw consistency)
+  /*
+    actually, no, don't.  that screws up our "latest" stash.  and can
+    lead to weird output where things appear to jump backwards in
+    time... that's just confusing.
+
+  if (pg_map.osd_stat.count(from))
+    pg_map.stat_osd_sub(pg_map.osd_stat[from]);
   pg_map.osd_stat[from] = stats->osd_stat;
   pg_map.stat_osd_add(stats->osd_stat);
+  */
 
   // pg stats
   MPGStatsAck *ack = new MPGStatsAck;
@@ -367,10 +374,12 @@ bool PGMonitor::prepare_pg_stats(MPGStats *stats)
             << dendl;
     pending_inc.pg_stat_updates[pgid] = p->second;
 
+    /*
     // we don't care much about consistency, here; apply to live map.
     pg_map.stat_pg_sub(pgid, pg_map.pg_stat[pgid]);
     pg_map.pg_stat[pgid] = p->second;
     pg_map.stat_pg_add(pgid, pg_map.pg_stat[pgid]);
+    */
   }
   
   paxos->wait_for_commit(new C_Stats(this, ack, stats->get_orig_source_inst()));