Hi there
I am getting an UnknownRowLockException when adding locks to the increment()
function below. The full stack trace is at the end of this message.
There are a few other places I am acquiring locks, but I only ever acquire a
single lock for one piece of code and the rest go through fine. It's only when
I enable the locks in this function that I get the exception. It's fairly
simple, and I can't find anything obviously wrong with it so my best guess is
there's some quirk with hbase locks that I'm unaware of. Any ideas?
One thing to note is that I am calling increment() a couple times consecutively
for the same row.
Marco
public static void increment(String tableName, String key, String family,
String qualifier, int value, boolean useShort,
Configuration config)
throws IOException{
HTable table = new HTable(config,
config.get("app", "geomon-test") + "." + tableName);
Get get = new Get(key.getBytes());
get.addColumn(family.getBytes(),
qualifier.getBytes());
int before = 0;
RowLock lock = table.lockRow(key.getBytes());
try {
Result result = table.get(get);
if (!result.isEmpty()) {
if (useShort) {
before = (int) Bytes.toShort(result.getValue(family.getBytes(),
qualifier.getBytes()));
} else {
before = Bytes.toInt(result.getValue(family.getBytes(),
qualifier.getBytes()));
}
}
if (useShort) {
value = Math.min(before + value, Short.MAX_VALUE);
} else {
value = (int) Math.min((long) before + value, Integer.MAX_VALUE);
}
Put put = new Put(key.getBytes());
put.add(family.getBytes(),
qualifier.getBytes(),
Bytes.toBytes(useShort ? (short) value : value));
table.put(put);
} catch (Exception e) {
System.err.println(e.getMessage());
} finally {
table.unlockRow(lock);
}
}
12/07/24 14:20:58 INFO mapred.JobClient: Task Id :
attempt_201207241320_0002_r_000000_2, Status :
FAILEDorg.apache.hadoop.hbase.UnknownRowLockException:
org.apache.hadoop.hbase.UnknownRowLockException: -3110061788478328763
at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
at
sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:57)
at
sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45)
at java.lang.reflect.Constructor.newInstance(Constructor.java:532)
at
org.apache.hadoop.ipc.RemoteException.instantiateException(RemoteException.java:95)
at
org.apache.hadoop.ipc.RemoteException.unwrapRemoteException(RemoteException.java:79)
at
org.apache.hadoop.hbase.client.ServerCallable.translateException(ServerCallable.java:228)
at
org.apache.hadoop.hbase.client.ServerCallable.withRetries(ServerCallable.java:166)
at org.apache.hadoop.hbase.client.HTable.unlockRow(HTable.java:1031)
at Util.increment(Util.java:170)
at Aggregate$EventReducer.processUserEvent(Aggregate.java:161)
at Aggregate$EventReducer.processUser(Aggregate.java:119)
at Aggregate$EventReducer.reduce(Aggregate.java:189)
at Aggregate$EventReducer.reduce(Aggregate.java:78)
at org.apache.hadoop.mapreduce.Reducer.run(Reducer.java:176)
at
org.apache.hadoop.mapred.ReduceTask.runNewReducer(ReduceTask.java:649)
at org.apache.hadoop.mapred.ReduceTask.run(ReduceTask.java:417)
at org.apache.hadoop.mapred.Child$4.run(Child.java:255)
at java.security.AccessController.doPrivileged(Native Method)
at javax.security.auth.Subject.doAs(Subject.java:416)
at
org.apache.hadoop.security.UserGroupInformation.doAs(UserGroupInformation.java:1121)
at org.apache.hadoop.mapred.Child.main(Child.java:249)
Caused by: org.apache.hadoop.ipc.RemoteException:
org.apache.hadoop.hbase.UnknownRowLockException: -3110061788478328763
at
org.apache.hadoop.hbase.regionserver.HRegionServer.unlockRow(HRegionServer.java:2633)
at sun.reflect.GeneratedMethodAccessor28.invoke(Unknown Source)
at
sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:616)
at
org.apache.hadoop.hbase.ipc.WritableRpcEngine$Server.call(WritableRpcEngine.java:364)
at
org.apache.hadoop.hbase.ipc.HBaseServer$Handler.run(HBaseServer.java:1376)
at org.apache.hadoop.hbase.ipc.HBaseClient.call(HBaseClient.java:918)
at
org.apache.hadoop.hbase.ipc.WritableRpcEngine$Invoker.invoke(WritableRpcEngine.java:150)
at $Proxy3.unlockRow(Unknown Source)
at org.apache.hadoop.hbase.client.HTable$15.call(HTable.java:1033)
at org.apache.hadoop.hbase.client.HTable$15.call(HTable.java:1031)
at
org.apache.hadoop.hbase.client.ServerCallable.withRetries(ServerCallable.java:163)
... 14 more
--
Marco Gallotta | Mountain View, California
Software Engineer, Infrastructure | Loki Studios
fb.me/marco.gallotta | twitter.com/marcog
[email protected] | +1 (650) 417-3313
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