HTablePool$**PooledHTable is a wrapper around HTable.
Here is how HTable obtains a connection:
public HTable(Configuration conf, final byte[] tableName, final
ExecutorService pool)
throws IOException {
this.connection = HConnectionManager.getConnection(conf);
Meaning the connection is a shared one based on certain key/value pairs
from conf.
bq. So every call to batch will create a new thread?
I don't think so.
On Thu, May 30, 2013 at 11:28 AM, Kireet <[email protected]> wrote:
>
>
> Thanks, will give it a shot. So I should download 0.94.7 (latest stable)
> and run the patch tool on top with the backport? This is a little new to me.
>
> Also, I was looking at the stack below. From my reading of the code, the
> HTable.batch() call will always cause the prefetch call to occur, which
> will cause a new HTable object to get created. The constructor used in
> creating a new thread pool. So every call to batch will create a new
> thread? Or the HTable's thread pool never gets used as the pool is only
> used for writes? I think I am missing something but just want to confirm.
>
> Thanks
> Kireet
>
> On 5/30/13 12:48 PM, Himanshu Vashishtha wrote:
>
>> bq. Anoop attached backported patch in HBASE-8655. It should go into
>>
>> 0.94.9, the next release - current is 0.94.8
>>
>> In case you want it sooner, you can apply 8655 patch and test/verify it.
>>
>> Thanks,
>> Himanshu
>>
>>
>>
>> On Thu, May 30, 2013 at 7:26 AM, Ted Yu <yuzhihong-**
>> Re5JQEeQqe8AvxtiuMwx3w@public.**gmane.org<[email protected]>>
>> wrote:
>>
>> Anoop attached backported patch in HBASE-8655
>>>
>>> It should go into 0.94.9, the next release - current is 0.94.8
>>>
>>> Cheers
>>>
>>> On Thu, May 30, 2013 at 7:01 AM, Kireet <kireet-Teh5dPVPL8nQT0dZR+**
>>> [email protected] <kireet-teh5dpvpl8nqt0dzr%[email protected]>>
>>> wrote:
>>>
>>>
>>>>
>>>> How long do backports typically take? We have to go live in a month
>>>> ready
>>>> or not. Thanks for the quick replies Anoop and Ted.
>>>>
>>>> --Kireet
>>>>
>>>>
>>>> On 5/30/13 9:20 AM, Ted Yu wrote:
>>>>
>>>> 0.95 client is not compatible with 0.94 cluster. So you cannot use 0.95
>>>>> client.
>>>>>
>>>>> Cheers
>>>>>
>>>>> On May 30, 2013, at 6:12 AM, Kireet <kireet-Teh5dPVPL8nQT0dZR+**
>>>>> AlfA-XMD5yJDbdMReXY1tMh2IBg@**public.gmane.org<[email protected]><
>>>>> kireet-Teh5dPVPL8nQT0dZR%**2BAlfA-XMD5yJDbdMReXY1tMh2IBg@**
>>>>> public.gmane.org<kireet-teh5dpvpl8nqt0dzr%[email protected]>
>>>>>
>>>>>
>>>>> wrote:
>>>>>
>>>>>
>>>>>
>>>>>> Would there be a problem if our cluster is 0.94 and we use a 0.95
>>>>>>
>>>>> client?
>>>
>>>>
>>>>>> I am not familiar with the HBase code base, but I did a dump of the
>>>>>> thread that is actually running (below). It seems like it is related
>>>>>>
>>>>> to the
>>>
>>>> issue you mentioned as the running thread is doing the prefetch logic.
>>>>>> Would pre-splitting tables help here? We are doing some performance
>>>>>>
>>>>> tests
>>>
>>>> and essentially starting from an empty instance.
>>>>>>
>>>>>> java.lang.Thread.State: WAITING (on object monitor)
>>>>>> at java.lang.Object.wait(Native Method)
>>>>>> at java.lang.Object.wait(Object.****java:503)
>>>>>> at org.apache.zookeeper.****ClientCnxn.submitRequest(**
>>>>>> ClientCnxn.java:1309)
>>>>>> - locked <0x00000000e10cf830> (a org.apache.zookeeper.**
>>>>>> ClientCnxn$Packet)
>>>>>> at org.apache.zookeeper.****ZooKeeper.exists(ZooKeeper.****java:1036)
>>>>>> at org.apache.hadoop.hbase.****zookeeper.****
>>>>>> RecoverableZooKeeper.exists(**
>>>>>> RecoverableZooKeeper.java:172)
>>>>>> at org.apache.hadoop.hbase.****zookeeper.ZKUtil.checkExists(****
>>>>>> ZKUtil.java:450)
>>>>>> at org.apache.hadoop.hbase.****zookeeper.****ZooKeeperNodeTracker.**
>>>>>> checkIfBaseNodeAvailable(****ZooKeeperNodeTracker.java:208)
>>>>>> at org.apache.hadoop.hbase.****zookeeper.RootRegionTracker.**
>>>>>> waitRootRegionLocation(****RootRegionTracker.java:77)
>>>>>> at org.apache.hadoop.hbase.****client.HConnectionManager$**
>>>>>> HConnectionImplementation.****locateRegion(****
>>>>>> HConnectionManager.java:874)
>>>>>> at org.apache.hadoop.hbase.****client.HConnectionManager$**
>>>>>> HConnectionImplementation.****locateRegionInMeta(**
>>>>>> HConnectionManager.java:987)
>>>>>> at org.apache.hadoop.hbase.****client.HConnectionManager$**
>>>>>> HConnectionImplementation.****locateRegion(****
>>>>>> HConnectionManager.java:885)
>>>>>> at org.apache.hadoop.hbase.****client.HConnectionManager$**
>>>>>> HConnectionImplementation.****locateRegion(****
>>>>>> HConnectionManager.java:846)
>>>>>> at org.apache.hadoop.hbase.****client.HTable.finishSetup(**
>>>>>> HTable.java:234)
>>>>>> at org.apache.hadoop.hbase.****client.HTable.<init>(HTable.****
>>>>>> java:174)
>>>>>> at org.apache.hadoop.hbase.****client.MetaScanner.metaScan(**
>>>>>> MetaScanner.java:160)
>>>>>> at org.apache.hadoop.hbase.****client.MetaScanner.access$000(****
>>>>>> MetaScanner.java:54)
>>>>>> at org.apache.hadoop.hbase.****client.MetaScanner$1.connect(****
>>>>>> MetaScanner.java:133)
>>>>>> at org.apache.hadoop.hbase.****client.MetaScanner$1.connect(****
>>>>>> MetaScanner.java:130)
>>>>>> at org.apache.hadoop.hbase.****client.HConnectionManager.**
>>>>>> execute(HConnectionManager.****java:383)
>>>>>> at org.apache.hadoop.hbase.****client.MetaScanner.metaScan(**
>>>>>> MetaScanner.java:130)
>>>>>> at org.apache.hadoop.hbase.****client.MetaScanner.metaScan(**
>>>>>> MetaScanner.java:105)
>>>>>> at org.apache.hadoop.hbase.****client.HConnectionManager$**
>>>>>> HConnectionImplementation.****prefetchRegionCache(**
>>>>>> HConnectionManager.java:947)
>>>>>> at org.apache.hadoop.hbase.****client.HConnectionManager$**
>>>>>> HConnectionImplementation.****locateRegionInMeta(**
>>>>>>
>>>>>> HConnectionManager.java:1002)
>>>>>> - locked <0x00000000e882f778> (a java.lang.Object)
>>>>>> at org.apache.hadoop.hbase.****client.HConnectionManager$**
>>>>>> HConnectionImplementation.****locateRegion(****
>>>>>> HConnectionManager.java:889)
>>>>>> at org.apache.hadoop.hbase.****client.HConnectionManager$**
>>>>>> HConnectionImplementation.****locateRegion(****
>>>>>> HConnectionManager.java:846)
>>>>>> at org.apache.hadoop.hbase.****client.HConnectionManager$**
>>>>>> HConnectionImplementation.****processBatchCallback(**
>>>>>> HConnectionManager.java:1533)
>>>>>> at org.apache.hadoop.hbase.****client.HConnectionManager$**
>>>>>>
>>>>>> HConnectionImplementation.****processBatch(****
>>> HConnectionManager.java:1418)
>>>
>>>> at org.apache.hadoop.hbase.****client.HTable.batch(HTable.****java:702)
>>>>>> at org.apache.hadoop.hbase.****client.HTable.get(HTable.java:****671)
>>>>>> at org.apache.hadoop.hbase.****client.HTablePool$**
>>>>>> PooledHTable.get(HTablePool.****java:367)
>>>>>>
>>>>>>
>>>>>> Thanks
>>>>>> Kireet
>>>>>>
>>>>>> On 5/30/13 12:16 AM, Anoop John wrote:
>>>>>>
>>>>>> Can you have a look at issue HBASE-8476? Seems related? A fix is
>>>>>>> available in HBASE-8346's patch..
>>>>>>>
>>>>>>> -Anoop-
>>>>>>>
>>>>>>> On Thu, May 30, 2013 at 9:21 AM, Kireet <kireet-Teh5dPVPL8nQT0dZR+**
>>>>>>> AlfA-XMD5yJDbdMReXY1tMh2IBg@**public.gmane.org<[email protected]>
>>>>>>> <
>>>>>>>
>>>>>> kireet-Teh5dPVPL8nQT0dZR%**2BAlfA-XMD5yJDbdMReXY1tMh2IBg@**
>>> public.gmane.org<kireet-teh5dpvpl8nqt0dzr%[email protected]>
>>> >>
>>>
>>> wrote:
>>>>>>>
>>>>>>> We are running hbase 0.94.6 in a concurrent environment and we are
>>>>>>>
>>>>>>>> seeing
>>>>>>>> the majority of our code stuck in this method at the synchronized
>>>>>>>>
>>>>>>> block
>>>
>>>> (line 997). Is there some configuration we can change to avoid it? It
>>>>>>>> seems
>>>>>>>> like we could disable prefetching, but that sounds like it could
>>>>>>>>
>>>>>>> cause
>>>
>>>> other problems?
>>>>>>>>
>>>>>>>> - org.apache.hadoop.hbase.******client.HConnectionManager$**
>>>>>>>> HConnectionImplementation.******locateRegionInMeta(byte[], byte[],
>>>>>>>>
>>>>>>>> byte[],
>>>>>>>> boolean, java.lang.Object, boolean) @bci=149, line=997 (Compiled
>>>>>>>>
>>>>>>> frame)
>>>
>>>> - org.apache.hadoop.hbase.******client.HConnectionManager$**
>>>>>>>> HConnectionImplementation.******locateRegion(byte[], byte[],
>>>>>>>> boolean,
>>>>>>>>
>>>>>>>> boolean) @bci=212, line=889 (Compiled frame)
>>>>>>>> - org.apache.hadoop.hbase.******client.HConnectionManager$**
>>>>>>>> HConnectionImplementation.******locateRegion(byte[], byte[])
>>>>>>>> @bci=5,
>>>>>>>> line=846
>>>>>>>> (Compiled frame)
>>>>>>>> - org.apache.hadoop.hbase.******client.HConnectionManager$**
>>>>>>>>
>>>>>>>> HConnectionImplementation.******processBatchCallback(java.******
>>> util.List,
>>>
>>>> byte[], java.util.concurrent.******ExecutorService, java.lang.Object[],
>>>>>>>> org.apache.hadoop.hbase.******client.coprocessor.Batch$******
>>>>>>>> Callback)
>>>>>>>> @bci=194,
>>>>>>>> line=1533 (Compiled frame)
>>>>>>>> - org.apache.hadoop.hbase.******client.HConnectionManager$**
>>>>>>>> HConnectionImplementation.******processBatch(java.util.List,
>>>>>>>> byte[],
>>>>>>>> java.util.concurrent.******ExecutorService, java.lang.Object[])
>>>>>>>>
>>>>>>> @bci=30,
>>>
>>>> line=1418 (Compiled frame)
>>>>>>>> - org.apache.hadoop.hbase.******client.HTable.batch(java.util.**
>>>>>>>> **
>>>>>>>>
>>>>>>>> **List)
>>>>>>>> @bci=24, line=702 (Compiled frame)
>>>>>>>> - org.apache.hadoop.hbase.******client.HTable.get(java.util.****
>>>>>>>> **List)
>>>>>>>> @bci=2,
>>>>>>>> line=671 (Compiled frame)
>>>>>>>> - org.apache.hadoop.hbase.******client.HTablePool$**
>>>>>>>> PooledHTable.get(java.util.******List) @bci=5, line=367 (Compiled
>>>>>>>>
>>>>>>> frame)
>>>
>>>>
>>>>>>>>
>>>>>>>
>>>>>>
>>>>>
>>>>
>>>
>>
>
