[HBASE-4890] fix possible NPE in HConnectionManager

• Type: Bug
• Status: Closed
• Priority: Blocker
• Resolution: Fixed
• Affects Version/s: 0.92.0
• Fix Version/s: 0.92.1, 0.94.0
• Hadoop Flags: Reviewed
• Assignee: Michael Stack
• Reporter: Jonathan Hsieh
• Created: 29/Nov/11 17:04
• Updated: 12/Oct/12 05:34
• Resolved: 08/Mar/12 05:02

Description

I was running YCSB against a 0.92 branch and encountered this error message:

11/11/29 08:47:16 WARN client.HConnectionManager$HConnectionImplementation: Failed all from region=usertable,user3917479014967760871,1322555655231.f78d161e5724495a9723bcd972f97f41., hostname=c0316.hal.cloudera.com, port=57020
java.util.concurrent.ExecutionException: java.lang.RuntimeException: java.lang.NullPointerException
        at java.util.concurrent.FutureTask$Sync.innerGet(FutureTask.java:222)
        at java.util.concurrent.FutureTask.get(FutureTask.java:83)
        at org.apache.hadoop.hbase.client.HConnectionManager$HConnectionImplementation.processBatchCallback(HConnectionManager.java:1501)
        at org.apache.hadoop.hbase.client.HConnectionManager$HConnectionImplementation.processBatch(HConnectionManager.java:1353)
        at org.apache.hadoop.hbase.client.HTable.flushCommits(HTable.java:898)
        at org.apache.hadoop.hbase.client.HTable.doPut(HTable.java:775)
        at org.apache.hadoop.hbase.client.HTable.put(HTable.java:750)
        at com.yahoo.ycsb.db.HBaseClient.update(Unknown Source)
        at com.yahoo.ycsb.DBWrapper.update(Unknown Source)
        at com.yahoo.ycsb.workloads.CoreWorkload.doTransactionUpdate(Unknown Source)
        at com.yahoo.ycsb.workloads.CoreWorkload.doTransaction(Unknown Source)
        at com.yahoo.ycsb.ClientThread.run(Unknown Source)
Caused by: java.lang.RuntimeException: java.lang.NullPointerException
        at org.apache.hadoop.hbase.client.HConnectionManager$HConnectionImplementation.getRegionServerWithoutRetries(HConnectionManager.java:1315)
        at org.apache.hadoop.hbase.client.HConnectionManager$HConnectionImplementation$3.call(HConnectionManager.java:1327)
        at org.apache.hadoop.hbase.client.HConnectionManager$HConnectionImplementation$3.call(HConnectionManager.java:1325)
        at java.util.concurrent.FutureTask$Sync.innerRun(FutureTask.java:303)
        at java.util.concurrent.FutureTask.run(FutureTask.java:138)
        at java.util.concurrent.ThreadPoolExecutor$Worker.runTask(ThreadPoolExecutor.java:886)
        at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:908)
        at java.lang.Thread.run(Thread.java:619)
Caused by: java.lang.NullPointerException
        at org.apache.hadoop.hbase.ipc.WritableRpcEngine$Invoker.invoke(WritableRpcEngine.java:158)
        at $Proxy4.multi(Unknown Source)
        at org.apache.hadoop.hbase.client.HConnectionManager$HConnectionImplementation$3$1.call(HConnectionManager.java:1330)
        at org.apache.hadoop.hbase.client.HConnectionManager$HConnectionImplementation$3$1.call(HConnectionManager.java:1328)
        at org.apache.hadoop.hbase.client.HConnectionManager$HConnectionImplementation.getRegionServerWithoutRetries(HConnectionManager.java:1309)
        ... 7 more

It looks like the NPE is caused by server being null in the MultiRespone call() method.

     public MultiResponse call() throws IOException {
         return getRegionServerWithoutRetries(
             new ServerCallable<MultiResponse>(connection, tableName, null) {
               public MultiResponse call() throws IOException {
                 return server.multi(multi);
               }
               @Override
               public void connect(boolean reload) throws IOException {
                 server =
                   connection.getHRegionConnection(loc.getHostname(), loc.getPort());
               }
             }
         );

Issue Links

• relates to: HBASE-5336 Spurious exceptions in HConnectionImplementation