[ZOOKEEPER-1683] ZooKeeper client NPE when updating server list on disconnected client

• Type: Bug
• Status: Resolved
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 3.5.0
• Fix Version/s: 3.5.0
• Component/s: java client
• Assignee: Alexander Shraer
• Reporter: Shevek
• Created: 04/Apr/13 22:20
• Updated: 18/Jul/14 11:35
• Resolved: 17/Jul/14 20:58

Description

2013-04-04 22:16:15,872 ERROR [pool-4-thread-1] com.netflix.curator.ConnectionState.getZooKeeper (ConnectionState.java:84) - Background exception caught
java.lang.NullPointerException
at org.apache.zookeeper.client.StaticHostProvider.updateServerList(StaticHostProvider.java:161) ~[zookeeper-3.5.0.jar:3.5.0--1]
at org.apache.zookeeper.ZooKeeper.updateServerList(ZooKeeper.java:183) ~[zookeeper-3.5.0.jar:3.5.0--1]
at com.netflix.curator.HandleHolder$1$1.setConnectionString(HandleHolder.java:121) ~[curator-client-1.3.5-SNAPSHOT.jar:?]

The duff code is this:

ClientCnxnSocket clientCnxnSocket = cnxn.sendThread.getClientCnxnSocket();
InetSocketAddress currentHost = (InetSocketAddress) clientCnxnSocket.getRemoteSocketAddress();
boolean reconfigMode = hostProvider.updateServerList(serverAddresses, currentHost);

Now, currentHost might be null, if we're not yet connected. But StaticHostProvider.updateServerList indirects on it unconditionally.

This would be caught by findbugs.

Issue Links

• is related to: CURATOR-15 LeaderSelector may (undetectably) fail to elect
• relates to: ZOOKEEPER-1684 Failure to update socket addresses on immedate connection
• relates to: ZOOKEEPER-1355 Add zk.updateServerList(newServerList)
• relates to: CURATOR-7 Session ids not preserved if EnsembleProvider has changed the ensemble