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https://issues.apache.org/jira/browse/HIVE-5172?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel
]
agate updated HIVE-5172:
------------------------
Status: Patch Available (was: Open)
Please review this patch. Its a minor change as noted in description above.
Checks transMap for cached TUGIContainingTransport, creates a new object and
adds it cache, and returns it (doesnt look in the cache after put, where the
possibility is that it wont be there if the entry has been garbage collected).
> TUGIContainingTransport returning null transport, causing intermittent
> SocketTimeoutException on hive client and NullPointerException in
> TUGIBasedProcessor on the server
> -------------------------------------------------------------------------------------------------------------------------------------------------------------------------
>
> Key: HIVE-5172
> URL: https://issues.apache.org/jira/browse/HIVE-5172
> Project: Hive
> Issue Type: Bug
> Components: Metastore
> Affects Versions: 0.11.0, 0.10.0, 0.9.0
> Reporter: agate
> Attachments: HIVE-5172.1.patch.txt
>
>
> We are running into frequent problem using HCatalog 0.4.1 (Hive Metastore
> Server 0.9) where we get connection reset or connection timeout errors on the
> client and NullPointerException in TUGIBasedProcessor on the server.
> {code}
> hive client logs:
> =================
> org.apache.thrift.transport.TTransportException:
> java.net.SocketTimeoutException: Read timed out
> at
> org.apache.thrift.transport.TIOStreamTransport.read(TIOStreamTransport.java:129)
> at org.apache.thrift.transport.TTransport.readAll(TTransport.java:84)
> at
> org.apache.thrift.protocol.TBinaryProtocol.readAll(TBinaryProtocol.java:378)
> at
> org.apache.thrift.protocol.TBinaryProtocol.readI32(TBinaryProtocol.java:297)
> at
> org.apache.thrift.protocol.TBinaryProtocol.readMessageBegin(TBinaryProtocol.java:204)
> at org.apache.thrift.TServiceClient.receiveBase(TServiceClient.java:69)
> at
> org.apache.hadoop.hive.metastore.api.ThriftHiveMetastore$Client.recv_set_ugi(ThriftHiveMetastore.java:2136)
> at
> org.apache.hadoop.hive.metastore.api.ThriftHiveMetastore$Client.set_ugi(ThriftHiveMetastore.java:2122)
> at
> org.apache.hadoop.hive.metastore.HiveMetaStoreClient.openStore(HiveMetaStoreClient.java:286)
> at
> org.apache.hadoop.hive.metastore.HiveMetaStoreClient.open(HiveMetaStoreClient.java:197)
> at
> org.apache.hadoop.hive.metastore.HiveMetaStoreClient.<init>(HiveMetaStoreClient.java:157)
> at
> org.apache.hadoop.hive.ql.metadata.Hive.createMetaStoreClient(Hive.java:2092)
> at org.apache.hadoop.hive.ql.metadata.Hive.getMSC(Hive.java:2102)
> at org.apache.hadoop.hive.ql.metadata.Hive.getTable(Hive.java:888)
> at org.apache.hadoop.hive.ql.metadata.Hive.getTable(Hive.java:830)
> at
> org.apache.hadoop.hive.ql.parse.SemanticAnalyzer.getMetaData(SemanticAnalyzer.java:954)
> at
> org.apache.hadoop.hive.ql.parse.SemanticAnalyzer.analyzeInternal(SemanticAnalyzer.java:7524)
> at
> org.apache.hadoop.hive.ql.parse.BaseSemanticAnalyzer.analyze(BaseSemanticAnalyzer.java:243)
> at org.apache.hadoop.hive.ql.Driver.compile(Driver.java:431)
> at org.apache.hadoop.hive.ql.Driver.compile(Driver.java:336)
> at org.apache.hadoop.hive.ql.Driver.run(Driver.java:909)
> at org.apache.hadoop.hive.cli.CliDriver.processLocalCmd(CliDriver.java:258)
> at org.apache.hadoop.hive.cli.CliDriver.processCmd(CliDriver.java:215)
> at org.apache.hadoop.hive.cli.CliDriver.processLine(CliDriver.java:406)
> at org.apache.hadoop.hive.cli.CliDriver.processLine(CliDriver.java:341)
> at org.apache.hadoop.hive.cli.CliDriver.run(CliDriver.java:642)
> at org.apache.hadoop.hive.cli.CliDriver.main(CliDriver.java:557)
> at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
> at
> sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
> at
> sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
> at java.lang.reflect.Method.invoke(Method.java:597)
> at org.apache.hadoop.util.RunJar.main(RunJar.java:156)
> Caused by: java.net.SocketTimeoutException: Read timed out
> at java.net.SocketInputStream.socketRead0(Native Method)
> at java.net.SocketInputStream.read(SocketInputStream.java:129)
> at
> org.apache.thrift.transport.TIOStreamTransport.read(TIOStreamTransport.java:127)
> ... 31 more
> {code}
> {code}
> hive metastore server logs:
> ===============================
> 2013-07-26 06:34:52,853 ERROR server.TThreadPoolServer
> (TThreadPoolServer.java:run(182)) - Error occurred during processing of
> message.
> java.lang.NullPointerException
> at
> org.apache.hadoop.hive.metastore.TUGIBasedProcessor.setIpAddress(TUGIBasedProcessor.java:183)
> at
> org.apache.hadoop.hive.metastore.TUGIBasedProcessor.process(TUGIBasedProcessor.java:79)
> at
> org.apache.thrift.server.TThreadPoolServer$WorkerProcess.run(TThreadPoolServer.java:176)
> at
> java.util.concurrent.ThreadPoolExecutor$Worker.runTask(ThreadPoolExecutor.java:886)
> at
> java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:908)
> at java.lang.Thread.run(Thread.java:662)
> {code}
> Adding some extra debug log messages in TUGIBasedProcessor, noticed that the
> TUGIContainingTransport is null which results in NullPointerException on the
> server.
> Further drilling into TUGIContainingTransport noticed that getTransport()
> returns a null which causes the above
> error.
> Further corelating with GC logs observed that that error always hits when the
> CMS GC has just kicked in
> (but does not happen after every GC)
> Put some debugging code in TUGIContainingTransport.getTransport() and I
> tracked it down to
> {code}
> @Override
> public TUGIContainingTransport getTransport(TTransport trans) {
> // UGI information is not available at connection setup time, it will
> be set later
> // via set_ugi() rpc.
> transMap.putIfAbsent(trans, new TUGIContainingTransport(trans));
> //return transMap.get(trans); //<-change
> TUGIContainingTransport retTrans = transMap.get(trans);
> if ( retTrans == null ) {
> LOGGER.error ("cannot find transport that was in map !!")
> return retTrans;
> } else {
> LOGGER.debug ("found transport in map")
> return retTrans;
> }
> }
> {code}
> When we run this in our test environment, see that we run into the problem
> just after GC runs,
> and "cannot find transport that was in the map!!" message gets logged.
> Could the GC be collecting entries from transMap, just before the we get it
> Tried a minor change which seems to work
> {code}
> public TUGIContainingTransport getTransport(TTransport trans) {
> TUGIContainingTransport tugiTrans = transMap.get(trans);
> if ( tugiTrans == null ) {
> // UGI information is not available at connection setup time, it will
> be set later
> // via set_ugi() rpc.
> tugiTrans = new TUGIContainingTransport(trans); //get a new
> TUGIContainingTransport
> transMap.putIfAbsent(trans, tugiTrans);
> }
> return tugiTrans;
> }
> {code}
> My questions for hive and thrift experts
> 1.) Do we need to use a ConcurrentMap
> {code}
> ConcurrentMap<TTransport, TUGIContainingTransport> transMap = new
> MapMaker().weakKeys().weakValues().makeMap();
> {code}
> It does use == to compare keys (which might be the problem), also in this
> case we cant rely on the trans to be always there in the transMap, even after
> a put, so in that case change above probably makes sense
> 2.) Is it better idea to use WeakHashMap with WeakReference value instead ?
> (was looking at org.apache.thrift.transport.TSaslServerTransport, especially
> change made by THRIFT-1468 as an example)
> e.g.
> {code}
> private static Map<TTransport, WeakReference<TUGIContainingTransport>>
> transMap = Collections.synchronizedMap(new WeakHashMap<TTransport,
> WeakReference<TUGIContainingTransport>>());
> {code}
> getTransport() would be something like
> {code}
> public TUGIContainingTransport getTransport(TTransport trans) {
> WeakReference<TUGIContainingTransport> ret = transMap.get(trans);
> if (ret == null || ret.get() == null) {
> ret = new WeakReference<TUGIContainingTransport>(new
> TUGIContainingTransport(trans));
> transMap.put(trans, ret); // No need for putIfAbsent().
> // Concurrent calls to getTransport() will pass in different
> TTransports.
> }
> return ret.get();
> }
> {code}
> 3.) Is it absolutely essential that successive calls to get getTransport()
> need to retrieve the same TUGIContainingTransport object or its ok to create
> a new one, if its not available in the map ?
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