Hi,
I have a replicated zookeeper services consisting of 3 zookeeper (3.0.1)
servers all running on the same host for testing purposes. I've created
exactly one znode in this ensemble. At this point, I stop, then restart
a single zookeeper server; moving onto the next one a few seconds later.
A few restarts later (about 4 is usually sufficient), I get the
following exception on one of the servers, at which point it exits:
java.lang.NullPointerException
at
org.apache.zookeeper.server.persistence.FileTxnLog$FileTxnIterator.next(FileTxnLog.java:447)
at
org.apache.zookeeper.server.persistence.FileTxnLog$FileTxnIterator.init(FileTxnLog.java:358)
at
org.apache.zookeeper.server.persistence.FileTxnLog$FileTxnIterator.<init>(FileTxnLog.java:333)
at
org.apache.zookeeper.server.persistence.FileTxnLog.read(FileTxnLog.java:250)
at
org.apache.zookeeper.server.persistence.FileTxnSnapLog.restore(FileTxnSnapLog.java:102)
at
org.apache.zookeeper.server.ZooKeeperServer.loadData(ZooKeeperServer.java:183)
at org.apache.zookeeper.server.quorum.Leader.lead(Leader.java:245)
at
org.apache.zookeeper.server.quorum.QuorumPeer.run(QuorumPeer.java:421)
2008-12-08 14:14:24,880 - INFO
[QuorumPeer:/0:0:0:0:0:0:0:0:2183:[EMAIL PROTECTED] - Shutdown called
java.lang.Exception: shutdown Leader! reason: Forcing shutdown
at
org.apache.zookeeper.server.quorum.Leader.shutdown(Leader.java:336)
at
org.apache.zookeeper.server.quorum.QuorumPeer.run(QuorumPeer.java:427)
Exception in thread "QuorumPeer:/0:0:0:0:0:0:0:0:2183"
java.lang.NullPointerException
at
org.apache.zookeeper.server.quorum.Leader.shutdown(Leader.java:339)
at
org.apache.zookeeper.server.quorum.QuorumPeer.run(QuorumPeer.java:427)
The inputStream field is null, apparently because next is being called
at line 358 even after next returns false. Having very little knowledge
about the implementation, I don't know if the existence of hdr.getZxid()
>= zxid is supposed to be an invariant across all invocations of the
server; however the following change to FileTxnLog.java seems to make
the problem go away.
diff FileTxnLog.java /tmp/FileTxnLog.java
358c358,359
< next();
---
> if (!next())
> return;
447c448,450
< inputStream.close();
---
> if (inputStream != null) {
> inputStream.close();
> }
Is this a bug?
Thanks.
