From: Sage Weil <sage@newdream.net>
Date: Wed, 26 May 2010 17:59:21 +0000 (-0700)
Subject: paxos: use helper to store committed state; fix master mon catch up using stash
X-Git-Tag: v0.22~488
X-Git-Url: http://git-server-git.apps.pok.os.sepia.ceph.com/?a=commitdiff_plain;h=a1c99811bae2199a4ef3eef8681ac70ccfa128f5;p=ceph.git

paxos: use helper to store committed state; fix master mon catch up using stash

The catch up logic in handle_last didn't handle the stashed state, so we
crashed and burned if it was the master that was behind and caught up.
Use a helper that does the work for handle_commit AND handle_last.
---

diff --git a/src/mon/Paxos.cc b/src/mon/Paxos.cc
index 91e96ca99a95..c3be917b4188 100644
--- a/src/mon/Paxos.cc
+++ b/src/mon/Paxos.cc
@@ -184,6 +184,42 @@ void Paxos::share_state(MMonPaxos *m, version_t peer_first_committed, version_t
   }
 }
 
+void Paxos::store_state(MMonPaxos *m)
+{
+  bool big_sync = m->values.size() > 5;
+
+  // stash?
+  if (m->latest_version && m->latest_version > last_committed) {
+    dout(10) << "store_state got stash version " << m->latest_version << ", zapping old states" << dendl;
+    stash_latest(m->latest_version, m->latest_value);
+
+    while (first_committed <= last_committed) {
+      dout(10) << "store_state trim " << first_committed << dendl;
+      mon->store->erase_sn(machine_name, first_committed);
+      first_committed++;
+    }
+    last_committed = m->latest_version;
+    first_committed = last_committed;
+    mon->store->put_int(first_committed, machine_name, "first_committed");
+  }
+
+  for (map<version_t,bufferlist>::iterator p = m->values.begin();
+       p != m->values.end();
+       ++p) {
+    if (p->first <= last_committed)
+      continue;
+    if (p->first > last_committed + 1)
+      break;
+    last_committed = p->first;
+    dout(10) << "store_state got " << last_committed << " (" << p->second.length() << " bytes)" << dendl;
+    mon->store->put_bl_sn(p->second, machine_name, last_committed, !big_sync);
+  }
+
+  mon->store->put_int(last_committed, machine_name, "last_committed");
+  if (big_sync)
+    mon->store->sync();
+}
+
 
 // leader
 void Paxos::handle_last(MMonPaxos *last)
@@ -207,28 +243,7 @@ void Paxos::handle_last(MMonPaxos *last)
   }
 
   // did we receive a committed value?
-  if (last->last_committed > last_committed) {
-    /* hmm.
-    if (last->latest_version) {
-      last_committed = last->latest_value;
-      dout(10) << "stashing latest full value " << last_committed << dendl;
-      stash_latest(last_committed, last->latest_value);
-    }
-    */
-    bool big_sync = last->last_committed - last_committed > 5;
-    for (version_t v = last_committed+1;
-	 v <= last->last_committed;
-	 v++) {
-      mon->store->put_bl_sn(last->values[v], machine_name, v, !big_sync);
-      dout(10) << "committing " << v << " " 
-	       << last->values[v].length() << " bytes" << dendl;
-    }
-    if (big_sync)
-      mon->store->sync();
-    last_committed = last->last_committed;
-    mon->store->put_int(last_committed, machine_name, "last_committed");
-    dout(10) << "last_committed now " << last_committed << dendl;
-  }
+  store_state(last);
       
   // do they accept your pn?
   if (last->pn > accepted_pn) {
@@ -482,6 +497,8 @@ void Paxos::commit()
 }
 
 
+
+
 void Paxos::handle_commit(MMonPaxos *commit)
 {
   dout(10) << "handle_commit on " << commit->last_committed << dendl;
@@ -493,37 +510,7 @@ void Paxos::handle_commit(MMonPaxos *commit)
     return;
   }
 
-  // commit locally.
-  bool big_sync = commit->values.size() > 2;
-
-  // stash?
-  if (commit->latest_version) {
-    dout(10) << "got stash version " << commit->latest_version << ", zapping old states" << dendl;
-    stash_latest(commit->latest_version, commit->latest_value);
-
-    while (first_committed <= last_committed) {
-      dout(10) << "trim " << first_committed << dendl;
-      mon->store->erase_sn(machine_name, first_committed);
-      first_committed++;
-    }
-    last_committed = commit->latest_version;
-    first_committed = last_committed;
-    mon->store->put_int(first_committed, machine_name, "first_committed");
-  }
-
-  for (map<version_t,bufferlist>::iterator p = commit->values.begin();
-       p != commit->values.end();
-       ++p) {
-    assert(p->first <= last_committed+1);
-    if (p->first == last_committed+1) {
-      last_committed = p->first;
-      dout(10) << " storing " << last_committed << " (" << p->second.length() << " bytes)" << dendl;
-      mon->store->put_bl_sn(p->second, machine_name, last_committed, !big_sync);
-    }
-  }
-  if (big_sync)
-    mon->store->sync();
-  mon->store->put_int(last_committed, machine_name, "last_committed");
+  store_state(commit);
   
   commit->put();
 
diff --git a/src/mon/Paxos.h b/src/mon/Paxos.h
index 9c999ac1cefc..c6eff222fb6c 100644
--- a/src/mon/Paxos.h
+++ b/src/mon/Paxos.h
@@ -249,6 +249,8 @@ public:
   void peon_init();
 
   void share_state(MMonPaxos *m, version_t first_committed, version_t last_committed);
+  void store_state(MMonPaxos *m);
+
 
   // -- service interface --
   void wait_for_active(Context *c) {