Hi there,

I'm having problems accessing HBase from within a MapReduce programme on
my cluster. To locate the problem I've written a very simple test
programme. It runs fine on the master node, however on the other nodes I
get the same error that was causing problems in the MapReduce programme:

java.io.IOException:
org.apache.hadoop.hbase.client.HConnectionManager$HConnectionImplementation@2937d090
closed
     at
org.apache.hadoop.hbase.client.HConnectionManager$HConnectionImplementation.locateRegion(HConnectionManager.java:794)
     at
org.apache.hadoop.hbase.client.HConnectionManager$HConnectionImplementation.locateRegion(HConnectionManager.java:782)
     at org.apache.hadoop.hbase.client.HTable.finishSetup(HTable.java:251)
     at org.apache.hadoop.hbase.client.HTable.<init>(HTable.java:215)
     at org.apache.hadoop.hbase.client.HTable.<init>(HTable.java:173)
     at TestHBase.main(TestHBase.java:29)

This occurs after these lines in the programme:

         Configuration conf = HBaseConfiguration.create();
         conf.set("hbase.master", args[0]);
         HTable table = new HTable(conf, "Table1");
Note: I'm note accessing HBase through the InputFormat. I simply would
like to read out a few values in the setup-method of my mappers. hbase
shell seems to be working on all nodes just fine and I can ping and
telnet the master node on port 60000 from the other nodes.

What could be the problem? Am i missing something? I've installed HBase
with cloudera manager CDH4.

Kind regards,
Antony

check hbase conf exists in mr job environment .
On Jan 6, 2013 7:36 PM, <[EMAIL PROTECTED]> wrote:

> Hi there,
>
> I'm having problems accessing HBase from within a MapReduce programme on
> my cluster. To locate the problem I've written a very simple test
> programme. It runs fine on the master node, however on the other nodes I
> get the same error that was causing problems in the MapReduce programme:
>
> java.io.IOException: org.apache.hadoop.hbase.**client.HConnectionManager$*
> *HConnectionImplementation@**2937d090 closed
>     at org.apache.hadoop.hbase.**client.HConnectionManager$**
> HConnectionImplementation.**locateRegion(**HConnectionManager.java:794)
>     at org.apache.hadoop.hbase.**client.HConnectionManager$**
> HConnectionImplementation.**locateRegion(**HConnectionManager.java:782)
>     at org.apache.hadoop.hbase.**client.HTable.finishSetup(**
> HTable.java:251)
>     at org.apache.hadoop.hbase.**client.HTable.<init>(HTable.**java:215)
>     at org.apache.hadoop.hbase.**client.HTable.<init>(HTable.**java:173)
>     at TestHBase.main(TestHBase.java:**29)
>
> This occurs after these lines in the programme:
>
>         Configuration conf = HBaseConfiguration.create();
>         conf.set("hbase.master", args[0]);
>         HTable table = new HTable(conf, "Table1");
>
>
> Note: I'm note accessing HBase through the InputFormat. I simply would
> like to read out a few values in the setup-method of my mappers. hbase
> shell seems to be working on all nodes just fine and I can ping and telnet
> the master node on port 60000 from the other nodes.
>
> What could be the problem? Am i missing something? I've installed HBase
> with cloudera manager CDH4.
>
> Kind regards,
> Antony
>

Can anyone tell me when this exception is thrown?

Regards,
Antony

Am 06.01.2013 12:35, schrieb [EMAIL PROTECTED]:
> Hi there,
>
> I'm having problems accessing HBase from within a MapReduce programme
> on my cluster. To locate the problem I've written a very simple test
> programme. It runs fine on the master node, however on the other nodes
> I get the same error that was causing problems in the MapReduce
> programme:
>
> java.io.IOException:
> org.apache.hadoop.hbase.client.HConnectionManager$HConnectionImplementation@2937d090
> closed
>     at
> org.apache.hadoop.hbase.client.HConnectionManager$HConnectionImplementation.locateRegion(HConnectionManager.java:794)
>     at
> org.apache.hadoop.hbase.client.HConnectionManager$HConnectionImplementation.locateRegion(HConnectionManager.java:782)
>     at org.apache.hadoop.hbase.client.HTable.finishSetup(HTable.java:251)
>     at org.apache.hadoop.hbase.client.HTable.<init>(HTable.java:215)
>     at org.apache.hadoop.hbase.client.HTable.<init>(HTable.java:173)
>     at TestHBase.main(TestHBase.java:29)
>
> This occurs after these lines in the programme:
>
>         Configuration conf = HBaseConfiguration.create();
>         conf.set("hbase.master", args[0]);
>         HTable table = new HTable(conf, "Table1");
>
>
> Note: I'm note accessing HBase through the InputFormat. I simply would
> like to read out a few values in the setup-method of my mappers. hbase
> shell seems to be working on all nodes just fine and I can ping and
> telnet the master node on port 60000 from the other nodes.
>
> What could be the problem? Am i missing something? I've installed
> HBase with cloudera manager CDH4.
>
> Kind regards,
> Antony

Hi,

I had same exception when my master node died.
Then I found this code:

private HRegionLocation locateRegion(byte[] tableName, byte[] row, boolean useCache) throws IOException {
if (closed) throw new IOException(toString() + " closed");
.......

and
public void abort(String msg, Throwable t)
{
if ((t instanceof KeeperException.SessionExpiredException)) {
try {
LOG.info("This client just lost it's session with ZooKeeper, trying to reconnect.");

resetZooKeeperTrackers();
LOG.info("Reconnected successfully. This disconnect could have been caused by a network partition or a long-running GC pause, either way it's recommended that
you verify your environment.");

return;
} catch (ZooKeeperConnectionException e) {
LOG.error("Could not reconnect to ZooKeeper after session expiration, aborting");

t = e;
}
}
if (t != null) LOG.fatal(msg, t); else
LOG.fatal(msg);
aborted = true;
closed = true;
}

So, it happens when client looses connection to ZooKeeper and cant reconnect,
Or, simply, somebody calls HConnection.close()

08.01.2013 12:41, Antony Neu пишет:
> Can anyone tell me when this exception is thrown?
>
> Regards,
> Antony
>
> Am 06.01.2013 12:35, schrieb [EMAIL PROTECTED]:
>> Hi there,
>>
>> I'm having problems accessing HBase from within a MapReduce programme on my cluster. To locate the problem I've written a very simple test programme. It runs
>> fine on the master node, however on the other nodes I get the same error that was causing problems in the MapReduce programme:
>>
>> java.io.IOException: org.apache.hadoop.hbase.client.HConnectionManager$HConnectionImplementation@2937d090 closed
>> at org.apache.hadoop.hbase.client.HConnectionManager$HConnectionImplementation.locateRegion(HConnectionManager.java:794)
>> at org.apache.hadoop.hbase.client.HConnectionManager$HConnectionImplementation.locateRegion(HConnectionManager.java:782)
>> at org.apache.hadoop.hbase.client.HTable.finishSetup(HTable.java:251)
>> at org.apache.hadoop.hbase.client.HTable.<init>(HTable.java:215)
>> at org.apache.hadoop.hbase.client.HTable.<init>(HTable.java:173)
>> at TestHBase.main(TestHBase.java:29)
>>
>> This occurs after these lines in the programme:
>>
>> Configuration conf = HBaseConfiguration.create();
>> conf.set("hbase.master", args[0]);
>> HTable table = new HTable(conf, "Table1");
>>
>>
>> Note: I'm note accessing HBase through the InputFormat. I simply would like to read out a few values in the setup-method of my mappers. hbase shell seems to
>> be working on all nodes just fine and I can ping and telnet the master node on port 60000 from the other nodes.
>>
>> What could be the problem? Am i missing something? I've installed HBase with cloudera manager CDH4.
>>
>> Kind regards,
>> Antony
>
>