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https://issues.apache.org/jira/browse/ZOOKEEPER-2667?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel
]
Rakesh R resolved ZOOKEEPER-2667.
---------------------------------
Resolution: Invalid
Thanks [~haridsv] for your testing efforts and quick analysis. As per the
discussion this is not a problem and I'm closing the issue. Please refer
[discussion thread in
ZOOKEEPER-2139|https://issues.apache.org/jira/browse/ZOOKEEPER-2139?focusedCommentId=15827233&page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel#comment-15827233]
to understand the background.
> NPE in the patch for ZOOKEEPER-2139 when multiple connections are made
> ----------------------------------------------------------------------
>
> Key: ZOOKEEPER-2667
> URL: https://issues.apache.org/jira/browse/ZOOKEEPER-2667
> Project: ZooKeeper
> Issue Type: Bug
> Components: java client
> Affects Versions: 3.5.2, 3.6.0
> Reporter: Hari Krishna Dara
>
> ZOOKEEPER-2139 added support for connecting to multiple ZK services, but this
> also introduced a bug that causes a cryptic NPE. The client sees the below
> sort of error messages:
> {noformat}
> Exception while trying to create SASL client: java.lang.NullPointerException
> SASL authentication with Zookeeper Quorum member failed:
> javax.security.sasl.SaslException: saslClient failed to initialize properly:
> it's null.
> Error while calling watcher
> java.lang.NullPointerException
> at
> org.apache.hadoop.hbase.zookeeper.ZooKeeperWatcher.connectionEvent(ZooKeeperWatcher.java:581)
> at
> org.apache.hadoop.hbase.zookeeper.ZooKeeperWatcher.process(ZooKeeperWatcher.java:532)
> at
> org.apache.hadoop.hbase.zookeeper.PendingWatcher.process(PendingWatcher.java:40)
> at
> org.apache.zookeeper.ClientCnxn$EventThread.processEvent(ClientCnxn.java:579)
> at
> org.apache.zookeeper.ClientCnxn$EventThread.run(ClientCnxn.java:554)
> {noformat}
> The line at {{ZooKeeperWatcher.connectionEvent(ZooKeeperWatcher.java:581)}}
> points to the middle line below, where {{event.getState()}} is {{null}}:
> {noformat}
> private void connectionEvent(WatchedEvent event) {
> switch(event.getState()) {
> case SyncConnected:
> {noformat}
> However, the event's state is {{null}} because of a couple of other bugs,
> particularly an NPE that gets a mention in the log without a stacktrace. This
> first NPE causes an incorrect initialization of the event and results in the
> second NPE with the stacktrace.
> The reason for the first NPE comes from this code in {{ZookeeperSaslClient}}:
> {noformat}
> if (!initializedLogin) {
> ...
> }
> Subject subject = login.getSubject();
> {noformat}
> Before the patch for ZOOKEEPER-2139, both the {{login}} and
> {{initializedLogin}} were {{static}} fields of {{ZookeeperSaslClient}}. To
> support multiple ZK clients, the {{login}} field was changed from {{static}}
> to instance field, however the {{initializedLogin}} field was left as
> {{static}} field. Because of this, the subsequent attempts to connect to ZK
> think that the login doesn't need to be done and go ahead and blindly use the
> {{login}} variable which causes the NPE.
> At the core, the fix is simply to change {{initializedLogin}} to instance
> variable, but we have made a few additional changes to improve the logging
> and handle state. I will attach a patch soon.
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