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https://issues.apache.org/jira/browse/HBASE-17170?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=15690329#comment-15690329
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Ted Yu commented on HBASE-17170:
--------------------------------
Thanks for reporting this, Ankit.
Want to attach a patch ?
> HBase is also retrying DoNotRetryIOException because of class loader
> differences.
> ---------------------------------------------------------------------------------
>
> Key: HBASE-17170
> URL: https://issues.apache.org/jira/browse/HBASE-17170
> Project: HBase
> Issue Type: Bug
> Reporter: Ankit Singhal
> Assignee: Ankit Singhal
>
> The class loader used by API exposed by hadoop and the context class loader
> used by RunJar(bin/hadoop jar phoenix-client.jar …. ) are different resulting
> in classes loaded from jar not visible to other current class loader used by
> API.
> {code}
> 16/04/26 21:18:00 INFO client.RpcRetryingCaller: Call exception, tries=32,
> retries=35, started=491541 ms ago, cancelled=false, msg=
> 16/04/26 21:18:21 INFO client.RpcRetryingCaller: Call exception, tries=33,
> retries=35, started=511747 ms ago, cancelled=false, msg=
> 16/04/26 21:18:41 INFO client.RpcRetryingCaller: Call exception, tries=34,
> retries=35, started=531820 ms ago, cancelled=false, msg=
> Exception in thread "main" org.apache.phoenix.exception.PhoenixIOException:
> Failed after attempts=35, exceptions:
> Tue Apr 26 21:09:49 UTC 2016,
> RpcRetryingCaller{globalStartTime=1461704989282, pause=100, retries=35},
> org.apache.hadoop.hbase.ipc.RemoteWithExtrasException(org.apache.hadoop.hbase.NamespaceExistException):
> org.apache.hadoop.hbase.NamespaceExistException: SYSTEM
> at
> org.apache.hadoop.hbase.master.TableNamespaceManager.create(TableNamespaceManager.java:156)
> at
> org.apache.hadoop.hbase.master.TableNamespaceManager.create(TableNamespaceManager.java:131)
> at org.apache.hadoop.hbase.master.HMaster.createNamespace(HMaster.java:2553)
> at
> org.apache.hadoop.hbase.master.MasterRpcServices.createNamespace(MasterRpcServices.java:447)
> at
> org.apache.hadoop.hbase.protobuf.generated.MasterProtos$MasterService$2.callBlockingMethod(MasterProtos.java:58043)
> at org.apache.hadoop.hbase.ipc.RpcServer.call(RpcServer.java:2115)
> at org.apache.hadoop.hbase.ipc.CallRunner.run(CallRunner.java:102)
> {code}
> The actual problem is stated in the comment below
> https://issues.apache.org/jira/browse/PHOENIX-3495?focusedCommentId=15677081&page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel#comment-15677081
> If we are not loading hbase classes from Hadoop classpath(from where hadoop
> jars are getting loaded), then the RemoteException will not get unwrapped
> because of ClassNotFoundException and the client will keep on retrying even
> if the cause of exception is DoNotRetryIOException.
> RunJar#main() context class loader.
> {code}
> ClassLoader loader = createClassLoader(file, workDir);
> Thread.currentThread().setContextClassLoader(loader);
> Class<?> mainClass = Class.forName(mainClassName, true, loader);
> Method main = mainClass.getMethod("main", new Class[] {
> Array.newInstance(String.class, 0).getClass()
> });
> HBase classes can be loaded from jar(phoenix-client.jar):-
> hadoop --config /etc/hbase/conf/ jar
> ~/git/apache/phoenix/phoenix-client/target/phoenix-4.9.0-HBase-1.2-client.jar
> org.apache.phoenix.mapreduce.CsvBulkLoadTool --table GIGANTIC_TABLE --input
> /tmp/b.csv --zookeeper localhost:2181
> {code}
> API(using current class loader).
> {code}
> public class RpcRetryingCaller<T> {
> public IOException unwrapRemoteException() {
> try {
> Class<?> realClass = Class.forName(getClassName());
> return instantiateException(realClass.asSubclass(IOException.class));
> } catch(Exception e) {
> // cannot instantiate the original exception, just return this
> }
> return this;
> }
> {code}
> *Possible solution:-*
> We can create our own HBaseRemoteWithExtrasException(extension of
> RemoteWithExtrasException) so that default class loader will be the one from
> where the hbase classes are loaded and extend unwrapRemoteException() to
> throw exception if the unwrapping doesn’t take place because of CNF
> exception?
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