Author: jgray
Date: Sun Oct 24 22:31:46 2010
New Revision: 1026909
URL: http://svn.apache.org/viewvc?rev=1026909&view=rev
Log:
HBASE-3136 Stale reads from ZK can break the atomic CAS operations we have in
ZKAssign
Modified:
hbase/trunk/CHANGES.txt
hbase/trunk/src/main/java/org/apache/hadoop/hbase/zookeeper/ZKAssign.java
hbase/trunk/src/main/java/org/apache/hadoop/hbase/zookeeper/ZooKeeperWatcher.java
Modified: hbase/trunk/CHANGES.txt
URL:
http://svn.apache.org/viewvc/hbase/trunk/CHANGES.txt?rev=1026909&r1=1026908&r2=1026909&view=diff
==============================================================================
--- hbase/trunk/CHANGES.txt (original)
+++ hbase/trunk/CHANGES.txt Sun Oct 24 22:31:46 2010
@@ -610,6 +610,8 @@ Release 0.21.0 - Unreleased
attributes
HBASE-3143 Adding the tests' hbase-site.xml to the jar breaks some clients
HBASE-3139 Server shutdown processor stuck because meta not online
+ HBASE-3136 Stale reads from ZK can break the atomic CAS operations we
+ have in ZKAssign
IMPROVEMENTS
Modified:
hbase/trunk/src/main/java/org/apache/hadoop/hbase/zookeeper/ZKAssign.java
URL:
http://svn.apache.org/viewvc/hbase/trunk/src/main/java/org/apache/hadoop/hbase/zookeeper/ZKAssign.java?rev=1026909&r1=1026908&r2=1026909&view=diff
==============================================================================
--- hbase/trunk/src/main/java/org/apache/hadoop/hbase/zookeeper/ZKAssign.java
(original)
+++ hbase/trunk/src/main/java/org/apache/hadoop/hbase/zookeeper/ZKAssign.java
Sun Oct 24 22:31:46 2010
@@ -239,6 +239,7 @@ public class ZKAssign {
EventType.M_ZK_REGION_OFFLINE, region.getRegionName(), serverName);
synchronized(zkw.getNodes()) {
String node = getNodeName(zkw, region.getEncodedName());
+ zkw.sync(node);
zkw.getNodes().add(node);
int version = ZKUtil.checkExists(zkw, node);
if(version == -1) {
@@ -380,6 +381,7 @@ public class ZKAssign {
LOG.debug(zkw.prefix("Deleting existing unassigned " +
"node for " + regionName + " that is in expected state " +
expectedState));
String node = getNodeName(zkw, regionName);
+ zkw.sync(node);
Stat stat = new Stat();
byte [] bytes = ZKUtil.getDataNoWatch(zkw, node, stat);
if(bytes == null) {
@@ -645,6 +647,7 @@ public class ZKAssign {
}
String node = getNodeName(zkw, encoded);
+ zkw.sync(node);
// Read existing data of the node
Stat stat = new Stat();
Modified:
hbase/trunk/src/main/java/org/apache/hadoop/hbase/zookeeper/ZooKeeperWatcher.java
URL:
http://svn.apache.org/viewvc/hbase/trunk/src/main/java/org/apache/hadoop/hbase/zookeeper/ZooKeeperWatcher.java?rev=1026909&r1=1026908&r2=1026909&view=diff
==============================================================================
---
hbase/trunk/src/main/java/org/apache/hadoop/hbase/zookeeper/ZooKeeperWatcher.java
(original)
+++
hbase/trunk/src/main/java/org/apache/hadoop/hbase/zookeeper/ZooKeeperWatcher.java
Sun Oct 24 22:31:46 2010
@@ -318,6 +318,22 @@ public class ZooKeeperWatcher implements
}
/**
+ * Forces a synchronization of this ZooKeeper client connection.
+ * <p>
+ * Executing this method before running other methods will ensure that the
+ * subsequent operations are up-to-date and consistent as of the time that
+ * the sync is complete.
+ * <p>
+ * This is used for compareAndSwap type operations where we need to read the
+ * data of an existing node and delete or transition that node, utilizing the
+ * previously read version and data. We want to ensure that the version read
+ * is up-to-date from when we begin the operation.
+ */
+ public void sync(String path) {
+ this.zooKeeper.sync(path, null, null);
+ }
+
+ /**
* Get the set of already watched unassigned nodes.
* @return
*/
