storage: fix save or reset of 'backup_tid' config value

Because masters don't have persistent storage, the task to remember whether
the cluster is in backup mode or not is delegated to storages, via the presence
of a 'backup_tid' config value.

This fixes a bug that set 'backup_tid' after a simple replication.
If the cluster was restarted, it would have tried to switch to BACKINGUP state.

neo/storage/app.py

@@ -18,7 +18,8 @@ import sys
 from collections import deque
 
 from neo.lib import logging
-from neo.lib.protocol import uuid_str, CellStates, NodeTypes, Packets
+from neo.lib.protocol import uuid_str, \
+    CellStates, ClusterStates, NodeTypes, Packets
 from neo.lib.node import NodeManager
 from neo.lib.event import EventManager
 from neo.lib.connection import ListeningConnection
@@ -312,6 +313,10 @@ class Application(object):
             for node in self.nm.getStorageList(only_identified=True):
                 node.getConnection().close()
 
+    def changeClusterState(self, state):
+        if state == ClusterStates.STOPPING_BACKUP:
+            self.dm.setBackupTID(None)
+
     def wait(self):
         # change handler
         logging.info("waiting in hidden state")

neo/storage/handlers/__init__.py

@@ -33,8 +33,7 @@ class BaseMasterHandler(EventHandler):
         raise PrimaryFailure('re-election occurs')
 
     def notifyClusterInformation(self, conn, state):
-        logging.warning('ignoring notify cluster information in %s',
-                self.__class__.__name__)
+        self.app.changeClusterState(state)
 
     def notifyLastOID(self, conn, oid):
         self.app.dm.setLastOID(oid)

neo/storage/replicator.py

@@ -113,8 +113,9 @@ class Replicator(object):
         for offset, p in self.partition_dict.iteritems():
             if offset not in outdated_set:
                 tid = min(tid, p.next_trans, p.next_obj)
-        if tid not in (ZERO_TID, INVALID_TID):
+        if ZERO_TID != tid != INVALID_TID:
             return add64(tid, -1)
+        return ZERO_TID
 
     def populate(self):
         app = self.app
@@ -292,7 +293,9 @@ class Replicator(object):
         del self.current_partition, self.replicate_tid, self.next_backup_tid
         p = self.partition_dict[offset]
         p.next_obj = add64(tid, 1)
-        self.app.dm.setBackupTID(self.getBackupTID())
+        dm = self.app.dm
+        if dm.getBackupTID() is not None:
+            dm.setBackupTID(self.getBackupTID())
         if not p.max_ttid:
             p = Packets.NotifyReplicationDone(offset, tid)
             self.app.master_conn.notify(p)