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Posted to user@hive.apache.org by labtrax <hi...@gmx.de> on 2011/05/19 11:49:43 UTC

multiple hive access

Hello,

I am running a cloudera hadoop/hbase cluster. I trying to integrate hive with that.
I need multiple (read) accesses to hive per Java/jdbc-client. Is this possible in any way? 
Following this http://wiki.apache.org/hadoop/Hive/HiveServer it might not be possible...
But what does it means exactly "The HiveServer is currently single threaded, which could present serious use limitations"...
If the hive server does it sequentially with correct results its ok for me.
See also this:
https://issues.apache.org/jira/browse/HIVE-80 (entry 27/Jan/11 15:38)

My initial plan was to get the concurrent accesses through multiple java clients in embded mode. This seems not to work with a cluster unfortunately. Seems "embedded mode" means it only works in hadoop embedded mode (without hdfs/cluster) on a single maschine.
I always get
 INFO metastore.HiveMetaStore: 0: Opening raw store with implemenation class:null
Exception in thread "main" java.lang.NullPointerException
        at java.lang.Class.forName0(Native Method)
        at java.lang.Class.forName(Class.java:247)
        at org.apache.hadoop.hive.metastore.HiveMetaStore$HMSHandler.getClass(HiveMetaStore.java:472)
        at org.apache.hadoop.hive.metastore.HiveMetaStore$HMSHandler.getMS(HiveMetaStore.java:354)
        at org.apache.hadoop.hive.metastore.HiveMetaStore$HMSHandler.executeWithRetry(HiveMetaStore.java:306)
        at org.apache.hadoop.hive.metastore.HiveMetaStore$HMSHandler.createDefaultDB(HiveMetaStore.java:451)
        at org.apache.hadoop.hive.metastore.HiveMetaStore$HMSHandler.init(HiveMetaStore.java:232)
        at org.apache.hadoop.hive.metastore.HiveMetaStore$HMSHandler.<init>(HiveMetaStore.java:191)
        at org.apache.hadoop.hive.service.HiveServer$HiveServerHandler.<init>(HiveServer.java:80)
        at org.apache.hadoop.hive.jdbc.HiveConnection.<init>(HiveConnection.java:84)
        at org.apache.hadoop.hive.jdbc.HiveDriver.connect(HiveDriver.java:110)
        at java.sql.DriverManager.getConnection(DriverManager.java:582)

Any clues?  

Thanks
labtrax
-- 
Empfehlen Sie GMX DSL Ihren Freunden und Bekannten und wir
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Re: multiple hive access

Posted by bharath vissapragada <bh...@gmail.com>.
Hey,

Embedded mode is used just for testing purposes and the only once process
can connect to it at a time. Configure it as a local/remote metastore. Refer
http://wiki.apache.org/hadoop/Hive/AdminManual/MetastoreAdmin for details .

Hope this helps.

Thanks and Regards.

On Thu, May 19, 2011 at 3:19 PM, labtrax <hi...@gmx.de> wrote:

> Hello,
>
> I am running a cloudera hadoop/hbase cluster. I trying to integrate hive
> with that.
> I need multiple (read) accesses to hive per Java/jdbc-client. Is this
> possible in any way?
> Following this http://wiki.apache.org/hadoop/Hive/HiveServer it might not
> be possible...
> But what does it means exactly "The HiveServer is currently single
> threaded, which could present serious use limitations"...
> If the hive server does it sequentially with correct results its ok for me.
> See also this:
> https://issues.apache.org/jira/browse/HIVE-80 (entry 27/Jan/11 15:38)
>
> My initial plan was to get the concurrent accesses through multiple java
> clients in embded mode. This seems not to work with a cluster unfortunately.
> Seems "embedded mode" means it only works in hadoop embedded mode (without
> hdfs/cluster) on a single maschine.
> I always get
>  INFO metastore.HiveMetaStore: 0: Opening raw store with implemenation
> class:null
> Exception in thread "main" java.lang.NullPointerException
>        at java.lang.Class.forName0(Native Method)
>        at java.lang.Class.forName(Class.java:247)
>        at
> org.apache.hadoop.hive.metastore.HiveMetaStore$HMSHandler.getClass(HiveMetaStore.java:472)
>        at
> org.apache.hadoop.hive.metastore.HiveMetaStore$HMSHandler.getMS(HiveMetaStore.java:354)
>        at
> org.apache.hadoop.hive.metastore.HiveMetaStore$HMSHandler.executeWithRetry(HiveMetaStore.java:306)
>        at
> org.apache.hadoop.hive.metastore.HiveMetaStore$HMSHandler.createDefaultDB(HiveMetaStore.java:451)
>        at
> org.apache.hadoop.hive.metastore.HiveMetaStore$HMSHandler.init(HiveMetaStore.java:232)
>        at
> org.apache.hadoop.hive.metastore.HiveMetaStore$HMSHandler.<init>(HiveMetaStore.java:191)
>        at
> org.apache.hadoop.hive.service.HiveServer$HiveServerHandler.<init>(HiveServer.java:80)
>        at
> org.apache.hadoop.hive.jdbc.HiveConnection.<init>(HiveConnection.java:84)
>        at
> org.apache.hadoop.hive.jdbc.HiveDriver.connect(HiveDriver.java:110)
>        at java.sql.DriverManager.getConnection(DriverManager.java:582)
>
> Any clues?
>
> Thanks
> labtrax
> --
> Empfehlen Sie GMX DSL Ihren Freunden und Bekannten und wir
> belohnen Sie mit bis zu 50,- Euro! https://freundschaftswerbung.gmx.de
>
> --
> Regards,
> Bharath .V
> w: <https://freundschaftswerbung.gmx.de>
> http://researchweb.iiit.ac.in/~bharath.v
>
>