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Posted to commits@cassandra.apache.org by sl...@apache.org on 2013/09/13 12:07:31 UTC
git commit: Fix paxos not always replaying when it should
Updated Branches:
refs/heads/cassandra-2.0 fa70e064c -> 50c9d77e1
Fix paxos not always replaying when it should
patch by slebresne; reviewed by jbellis for CASSANDRA-6012
Project: http://git-wip-us.apache.org/repos/asf/cassandra/repo
Commit: http://git-wip-us.apache.org/repos/asf/cassandra/commit/50c9d77e
Tree: http://git-wip-us.apache.org/repos/asf/cassandra/tree/50c9d77e
Diff: http://git-wip-us.apache.org/repos/asf/cassandra/diff/50c9d77e
Branch: refs/heads/cassandra-2.0
Commit: 50c9d77e1b2be206a765e7f86cd4b8ecf3d232df
Parents: fa70e06
Author: Sylvain Lebresne <sy...@datastax.com>
Authored: Fri Sep 13 12:06:46 2013 +0200
Committer: Sylvain Lebresne <sy...@datastax.com>
Committed: Fri Sep 13 12:06:46 2013 +0200
----------------------------------------------------------------------
CHANGES.txt | 1 +
.../apache/cassandra/service/StorageProxy.java | 4 ++--
.../service/paxos/PrepareCallback.java | 20 ++++++++++++++++----
3 files changed, 19 insertions(+), 6 deletions(-)
----------------------------------------------------------------------
http://git-wip-us.apache.org/repos/asf/cassandra/blob/50c9d77e/CHANGES.txt
----------------------------------------------------------------------
diff --git a/CHANGES.txt b/CHANGES.txt
index 814029d..ebdfddb 100644
--- a/CHANGES.txt
+++ b/CHANGES.txt
@@ -15,6 +15,7 @@
* Require superuser status for adding triggers (CASSANDRA-5963)
* Make standalone scrubber handle old and new style leveled manifest
(CASSANDRA-6005)
+ * Fix paxos not always replaying when it should (CASSANDRA-6012)
Merged from 1.2:
1.2.10
* Fix possible divide-by-zero in HHOM (CASSANDRA-5990)
http://git-wip-us.apache.org/repos/asf/cassandra/blob/50c9d77e/src/java/org/apache/cassandra/service/StorageProxy.java
----------------------------------------------------------------------
diff --git a/src/java/org/apache/cassandra/service/StorageProxy.java b/src/java/org/apache/cassandra/service/StorageProxy.java
index 1184bb5..83cb265 100644
--- a/src/java/org/apache/cassandra/service/StorageProxy.java
+++ b/src/java/org/apache/cassandra/service/StorageProxy.java
@@ -357,7 +357,7 @@ public class StorageProxy implements StorageProxyMBean
{
long ballotMillis = summary == null
? System.currentTimeMillis()
- : Math.max(System.currentTimeMillis(), 1 + UUIDGen.unixTimestamp(summary.inProgressCommit.ballot));
+ : Math.max(System.currentTimeMillis(), 1 + UUIDGen.unixTimestamp(summary.mostRecentInProgressCommit.ballot));
UUID ballot = UUIDGen.getTimeUUID(ballotMillis);
// prepare
@@ -372,7 +372,7 @@ public class StorageProxy implements StorageProxyMBean
continue;
}
- Commit inProgress = summary.inProgressCommit;
+ Commit inProgress = summary.mostRecentInProgressCommitWithUpdate;
Commit mostRecent = summary.mostRecentCommit;
// If we have an in-progress ballot greater than the MRC we know, then it's an in-progress round that
http://git-wip-us.apache.org/repos/asf/cassandra/blob/50c9d77e/src/java/org/apache/cassandra/service/paxos/PrepareCallback.java
----------------------------------------------------------------------
diff --git a/src/java/org/apache/cassandra/service/paxos/PrepareCallback.java b/src/java/org/apache/cassandra/service/paxos/PrepareCallback.java
index 23d7952..9293254 100644
--- a/src/java/org/apache/cassandra/service/paxos/PrepareCallback.java
+++ b/src/java/org/apache/cassandra/service/paxos/PrepareCallback.java
@@ -40,7 +40,8 @@ public class PrepareCallback extends AbstractPaxosCallback<PrepareResponse>
public boolean promised = true;
public Commit mostRecentCommit;
- public Commit inProgressCommit;
+ public Commit mostRecentInProgressCommit;
+ public Commit mostRecentInProgressCommitWithUpdate;
private Map<InetAddress, Commit> commitsByReplica = new HashMap<InetAddress, Commit>();
@@ -49,7 +50,8 @@ public class PrepareCallback extends AbstractPaxosCallback<PrepareResponse>
super(targets);
// need to inject the right key in the empty commit so comparing with empty commits in the reply works as expected
mostRecentCommit = Commit.emptyCommit(key, metadata);
- inProgressCommit = Commit.emptyCommit(key, metadata);
+ mostRecentInProgressCommit = Commit.emptyCommit(key, metadata);
+ mostRecentInProgressCommitWithUpdate = Commit.emptyCommit(key, metadata);
}
public synchronized void response(MessageIn<PrepareResponse> message)
@@ -57,6 +59,12 @@ public class PrepareCallback extends AbstractPaxosCallback<PrepareResponse>
PrepareResponse response = message.payload;
logger.debug("Prepare response {} from {}", response, message.from);
+ // In case of clock skew, another node could be proposing with ballot that are quite a bit
+ // older than our own. In that case, we record the more recent commit we've received to make
+ // sure we re-prepare on an older ballot.
+ if (response.inProgressCommit.isAfter(mostRecentInProgressCommit))
+ mostRecentInProgressCommit = response.inProgressCommit;
+
if (!response.promised)
{
promised = false;
@@ -68,8 +76,12 @@ public class PrepareCallback extends AbstractPaxosCallback<PrepareResponse>
if (response.mostRecentCommit.isAfter(mostRecentCommit))
mostRecentCommit = response.mostRecentCommit;
- if (response.inProgressCommit.isAfter(inProgressCommit))
- inProgressCommit = response.inProgressCommit;
+ // If some response has an update, then we should replay the update with the highest ballot. So find
+ // the the highest commit that actually have an update
+ if (response.inProgressCommit.isAfter(mostRecentInProgressCommitWithUpdate) && !response.inProgressCommit.update.isEmpty())
+ mostRecentInProgressCommitWithUpdate = response.inProgressCommit;
+
+
latch.countDown();
}