From: Sage Weil <sage@inktank.com>
Date: Fri, 18 Jan 2013 05:38:49 +0000 (-0800)
Subject: mon: enforce unique name in mdsmap
X-Git-Tag: v0.58~67^2~2
X-Git-Url: http://git-server-git.apps.pok.os.sepia.ceph.com/?a=commitdiff_plain;h=2e112333397750a1b683c41f58c3fae05321fc49;p=ceph.git

mon: enforce unique name in mdsmap

Add 'mds enforce unique name' option, defaulting to true.

If set, when an MDS boots, it will kick any previous mds with the same
name from the mdsmap.  This is possibly less confusing for users.  If
an mds daemon restarts, it will immediately replace its previous
instantiation.

Two misconfigured daemons running with the same name will fight over
the same role.

Fixes: #3857
Signed-off-by: Sage Weil <sage@inktank.com>
---

diff --git a/src/common/config_opts.h b/src/common/config_opts.h
index a5df112576f9..c611041f5917 100644
--- a/src/common/config_opts.h
+++ b/src/common/config_opts.h
@@ -213,6 +213,7 @@ OPTION(mds_dir_max_commit_size, OPT_INT, 90) // MB
 OPTION(mds_decay_halflife, OPT_FLOAT, 5)
 OPTION(mds_beacon_interval, OPT_FLOAT, 4)
 OPTION(mds_beacon_grace, OPT_FLOAT, 15)
+OPTION(mds_enforce_unique_name, OPT_BOOL, true)
 OPTION(mds_blacklist_interval, OPT_FLOAT, 24.0*60.0)  // how long to blacklist failed nodes
 OPTION(mds_session_timeout, OPT_FLOAT, 60)    // cap bits and leases time out if client idle
 OPTION(mds_session_autoclose, OPT_FLOAT, 300) // autoclose idle session
diff --git a/src/mds/MDSMap.h b/src/mds/MDSMap.h
index 3a83ed88b08e..1314156f2d32 100644
--- a/src/mds/MDSMap.h
+++ b/src/mds/MDSMap.h
@@ -256,6 +256,16 @@ public:
     assert(up.count(m) && mds_info.count(up[m]));
     return mds_info[up[m]];
   }
+  uint64_t find_mds_gid_by_name(const string& s) {
+    for (map<uint64_t,mds_info_t>::const_iterator p = mds_info.begin();
+	 p != mds_info.end();
+	 ++p) {
+      if (p->second.name == s) {
+	return p->first;
+      }
+    }
+    return 0;
+  }
 
   // counts
   unsigned get_num_in_mds() {
diff --git a/src/mon/MDSMonitor.cc b/src/mon/MDSMonitor.cc
index 74bf8b1cb8c0..7585e42c5ea7 100644
--- a/src/mon/MDSMonitor.cc
+++ b/src/mon/MDSMonitor.cc
@@ -354,6 +354,13 @@ bool MDSMonitor::prepare_beacon(MMDSBeacon *m)
 
   // boot?
   if (state == MDSMap::STATE_BOOT) {
+    // zap previous instance of this name?
+    if (g_conf->mds_enforce_unique_name) {
+      while (uint64_t existing = pending_mdsmap.find_mds_gid_by_name(m->get_name())) {
+	fail_mds_gid(existing);
+      }
+    }
+
     // add
     MDSMap::mds_info_t& info = pending_mdsmap.mds_info[gid];
     info.global_id = gid;
@@ -376,7 +383,6 @@ bool MDSMonitor::prepare_beacon(MMDSBeacon *m)
       }
     }
 
-
     // initialize the beacon timer
     last_beacon[gid].stamp = ceph_clock_now(g_ceph_context);
     last_beacon[gid].seq = seq;
@@ -676,6 +682,8 @@ void MDSMonitor::fail_mds_gid(uint64_t gid)
 {
   assert(pending_mdsmap.mds_info.count(gid));
   MDSMap::mds_info_t& info = pending_mdsmap.mds_info[gid];
+  dout(10) << "fail_mds_gid " << gid << " mds." << info.name << " rank " << info.rank << dendl;
+
   utime_t until = ceph_clock_now(g_ceph_context);
   until += g_conf->mds_blacklist_interval;