hive-user mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From Alan Gates <ga...@hortonworks.com>
Subject Re: bug in hive
Date Sat, 20 Sep 2014 14:41:35 GMT
Up until Hive 0.13 locks in Hive were really advisory only, since as you 
note any user can remove any other user's lock.  In Hive 0.13 a new type 
of locking was introduced, see 
https://cwiki.apache.org/confluence/display/Hive/Hive+Transactions#HiveTransactions-LockManager
 
This new locking is automatic and ignores both LOCK and UNLOCK 
commands.  Note that it is off by default, you have to configure Hive to 
use the new DbTxnManager to get turn on this locking.  In 0.13 it still 
has the bug you describe as far as acquiring the wrong lock for dynamic 
partitioning, but I believe I've fixed that in 0.14.

Alan.

> Shushant Arora <mailto:shushantarora09@gmail.com>
> September 20, 2014 at 5:39
>
> Hive version 0.9 and later has a bug
>
> While inserting in a hive table Hive takes an exclusive lock. But if 
> table is partitioned , and insert is in dynamic partition , it will 
> take shared lock on table but if all partitions are static then hive 
> takes exclusive lock on partitions in which data is being inserted
>
> and shared lock on table.
>
> https://issues.apache.org/jira/browse/HIVE-3509
>
>
> 1.What if I want to take exclusive lock on table while inserting in 
> dynamic partition ?
>
>
> I tried to take explicit lock using :
>
> LOCK TABLE tablename EXCLUSIVE;
>
>
> But it made table to be disabled.
>
> I cannot even read from table anymore even is same session until I do
>
> unlock table tablename in another session;
>
>
> 2. moreover whats lock level in hive , I mean any user can remove any 
> other users lock. that too seems buggy.
>
>
> Thanks
>
> Shushant
>
>
>

-- 
Sent with Postbox <http://www.getpostbox.com>

-- 
CONFIDENTIALITY NOTICE
NOTICE: This message is intended for the use of the individual or entity to 
which it is addressed and may contain information that is confidential, 
privileged and exempt from disclosure under applicable law. If the reader 
of this message is not the intended recipient, you are hereby notified that 
any printing, copying, dissemination, distribution, disclosure or 
forwarding of this communication is strictly prohibited. If you have 
received this communication in error, please contact the sender immediately 
and delete it from your system. Thank You.

Mime
View raw message