[Zodb-checkins] CVS: ZODB3/ZEO - StorageServer.py:1.74.2.10.8.1 ServerStub.py:1.9.32.1 ClientStorage.py:1.73.2.27.2.1

[Jeremy Hylton]

Update of /cvs-repository/ZODB3/ZEO
In directory cvs.zope.org:/tmp/cvs-serv25983/ZEO

Modified Files:
      Tag: ZODB3-vote-backoff-branch
	StorageServer.py ServerStub.py ClientStorage.py 
Log Message:
Experimental version of non-blocking vote for ZEO.

Returns a special "VOTE_BACKOFF" response indicating that the client
should try again.  Still need to handle cases where server does not
support vote_nb().


=== ZODB3/ZEO/StorageServer.py 1.74.2.10 => 1.74.2.10.8.1 ===
--- ZODB3/ZEO/StorageServer.py:1.74.2.10	Tue Apr 29 17:39:56 2003
+++ ZODB3/ZEO/StorageServer.py	Wed Aug 20 13:41:13 2003
@@ -496,6 +496,13 @@
         self.check_tid(id, exc=StorageTransactionError)
         return self.strategy.tpc_vote()
 
+    def vote_nb(self, id):
+        self.check_tid(id, exc=StorageTransactionError)
+        if isinstance(self.strategy, DelayedCommitStrategy):
+            return self.strategy.tpc_vote_nb()
+        else:
+            return self.strategy.tpc_vote()
+
     def abortVersion(self, src, id):
         self.check_tid(id, exc=StorageTransactionError)
         return self.strategy.abortVersion(src)
@@ -732,6 +739,12 @@
         self.args = ()
         return self.block()
 
+    def tpc_vote_nb(self):
+        if self.storage._transaction:
+            return "VOTE_BACKOFF"
+        else:
+            return self.tpc_vote()
+
     def commitVersion(self, src, dest):
         self.name = "commitVersion"
         self.args = src, dest
@@ -751,6 +764,7 @@
         # called by the storage when the storage is available
         assert isinstance(new_strategy, ImmediateCommitStrategy)
         new_strategy.tpc_begin(self.txn, self.tid, self.status)
+        print "restarting blocked txn", self.log.stores
         loads, loader = self.log.get_loader()
         for i in range(loads):
             oid, serial, data, version = loader.load()


=== ZODB3/ZEO/ServerStub.py 1.9 => 1.9.32.1 ===
--- ZODB3/ZEO/ServerStub.py:1.9	Tue Oct  1 14:49:12 2002
+++ ZODB3/ZEO/ServerStub.py	Wed Aug 20 13:41:13 2003
@@ -81,6 +81,9 @@
     def vote(self, trans_id):
         return self.rpc.call('vote', trans_id)
 
+    def vote_nb(self, trans_id):
+        return self.rpc.call('vote_nb', trans_id)
+
     def tpc_finish(self, id):
         return self.rpc.call('tpc_finish', id)
 


=== ZODB3/ZEO/ClientStorage.py 1.73.2.27 => 1.73.2.27.2.1 ===
--- ZODB3/ZEO/ClientStorage.py:1.73.2.27	Mon Aug  4 18:13:58 2003
+++ ZODB3/ZEO/ClientStorage.py	Wed Aug 20 13:41:13 2003
@@ -727,7 +727,19 @@
         """Storage API: vote on a transaction."""
         if transaction is not self._transaction:
             return
-        self._server.vote(self._serial)
+        backoff = 0.24
+        attempts = 0
+        while 1:
+            if self._server.vote_nb(self._serial) == "VOTE_BACKOFF":
+                time.sleep(backoff)
+                attempts += 1
+                backoff *= 2
+                backoff = min(backoff, 60)
+                if attempts > 70:
+                    raise StorageSystemError("Timed out waiting to vote")
+                continue
+            else:
+                break
         return self._check_serials()
 
     def tpc_begin(self, transaction, tid=None, status=' '):