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https://issues.apache.org/jira/browse/FLINK-4311?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=15509694#comment-15509694
 ] 

ASF GitHub Bot commented on FLINK-4311:
---------------------------------------

Github user nielsbasjes commented on a diff in the pull request:

    https://github.com/apache/flink/pull/2330#discussion_r79816123
  
    --- Diff: 
flink-batch-connectors/flink-hbase/src/main/java/org/apache/flink/addons/hbase/TableInputFormat.java
 ---
    @@ -67,18 +66,23 @@
        protected abstract T mapResultToTuple(Result r);
     
        /**
    -    * creates a {@link Scan} object and a {@link HTable} connection
    +    * Creates a {@link Scan} object and opens the {@link HTable} 
connection.
    +    * These are opened here because they are needed in the 
createInputSplits
    +    * which is called before the openInputFormat method.
    +    * So the connection is opened in {@link #configure(Configuration)} and 
closed in {@link #closeInputFormat()}.
         *
    -    * @param parameters
    +    * @param parameters The configuration that is to be used
         * @see Configuration
         */
        @Override
        public void configure(Configuration parameters) {
    -           this.table = createTable();
    -           this.scan = getScanner();
    +           table = createTable();
    +           scan = getScanner();
    --- End diff --
    
    Done. Yet because 'configure()' doesn't have a way to fail nicely I added 
those checks to the other methods.


> TableInputFormat fails when reused on next split
> ------------------------------------------------
>
>                 Key: FLINK-4311
>                 URL: https://issues.apache.org/jira/browse/FLINK-4311
>             Project: Flink
>          Issue Type: Bug
>    Affects Versions: 1.0.3
>            Reporter: Niels Basjes
>            Assignee: Niels Basjes
>            Priority: Critical
>
> We have written a batch job that uses data from HBase by means of using the 
> TableInputFormat.
> We have found that this class sometimes fails with this exception:
> {quote}
> java.lang.RuntimeException: java.util.concurrent.RejectedExecutionException: 
> Task 
> org.apache.hadoop.hbase.client.ResultBoundedCompletionService$QueueingFuture@4f4efe4b
>  rejected from java.util.concurrent.ThreadPoolExecutor@7872d5c1[Terminated, 
> pool size = 0, active threads = 0, queued tasks = 0, completed tasks = 1165]
>       at 
> org.apache.hadoop.hbase.client.RpcRetryingCaller.callWithoutRetries(RpcRetryingCaller.java:208)
>       at 
> org.apache.hadoop.hbase.client.ClientScanner.call(ClientScanner.java:320)
>       at 
> org.apache.hadoop.hbase.client.ClientScanner.nextScanner(ClientScanner.java:295)
>       at 
> org.apache.hadoop.hbase.client.ClientScanner.initializeScannerInConstruction(ClientScanner.java:160)
>       at 
> org.apache.hadoop.hbase.client.ClientScanner.<init>(ClientScanner.java:155)
>       at org.apache.hadoop.hbase.client.HTable.getScanner(HTable.java:821)
>       at 
> org.apache.flink.addons.hbase.TableInputFormat.open(TableInputFormat.java:152)
>       at 
> org.apache.flink.addons.hbase.TableInputFormat.open(TableInputFormat.java:47)
>       at 
> org.apache.flink.runtime.operators.DataSourceTask.invoke(DataSourceTask.java:147)
>       at org.apache.flink.runtime.taskmanager.Task.run(Task.java:559)
>       at java.lang.Thread.run(Thread.java:745)
> Caused by: java.util.concurrent.RejectedExecutionException: Task 
> org.apache.hadoop.hbase.client.ResultBoundedCompletionService$QueueingFuture@4f4efe4b
>  rejected from java.util.concurrent.ThreadPoolExecutor@7872d5c1[Terminated, 
> pool size = 0, active threads = 0, queued tasks = 0, completed tasks = 1165]
>       at 
> java.util.concurrent.ThreadPoolExecutor$AbortPolicy.rejectedExecution(ThreadPoolExecutor.java:2047)
>       at 
> java.util.concurrent.ThreadPoolExecutor.reject(ThreadPoolExecutor.java:823)
>       at 
> java.util.concurrent.ThreadPoolExecutor.execute(ThreadPoolExecutor.java:1369)
>       at 
> org.apache.hadoop.hbase.client.ResultBoundedCompletionService.submit(ResultBoundedCompletionService.java:142)
>       at 
> org.apache.hadoop.hbase.client.ScannerCallableWithReplicas.addCallsForCurrentReplica(ScannerCallableWithReplicas.java:269)
>       at 
> org.apache.hadoop.hbase.client.ScannerCallableWithReplicas.call(ScannerCallableWithReplicas.java:165)
>       at 
> org.apache.hadoop.hbase.client.ScannerCallableWithReplicas.call(ScannerCallableWithReplicas.java:59)
>       at 
> org.apache.hadoop.hbase.client.RpcRetryingCaller.callWithoutRetries(RpcRetryingCaller.java:200)
>       ... 10 more
> {quote}
> As you can see the ThreadPoolExecutor was terminated at this point.
> We tracked it down to the fact that 
> # the configure method opens the table
> # the open method obtains the result scanner
> # the closes method closes the table.
> If a second split arrives on the same instance then the open method will fail 
> because the table has already been closed.
> We also found that this error varies with the versions of HBase that are 
> used. I have also seen this exception:
> {quote}
> Caused by: java.io.IOException: hconnection-0x19d37183 closed
>       at 
> org.apache.hadoop.hbase.client.ConnectionManager$HConnectionImplementation.locateRegion(ConnectionManager.java:1146)
>       at 
> org.apache.hadoop.hbase.client.RpcRetryingCallerWithReadReplicas.getRegionLocations(RpcRetryingCallerWithReadReplicas.java:300)
>       ... 37 more
> {quote}
> I found that in the [documentation of the InputFormat 
> interface|https://ci.apache.org/projects/flink/flink-docs-master/api/java/org/apache/flink/api/common/io/InputFormat.html]
>  is clearly states
> {quote}IMPORTANT NOTE: Input formats must be written such that an instance 
> can be opened again after it was closed. That is due to the fact that the 
> input format is used for potentially multiple splits. After a split is done, 
> the format's close function is invoked and, if another split is available, 
> the open function is invoked afterwards for the next split.{quote}
> It appears that this specific InputFormat has not been checked against this 
> constraint.



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