Status: Patch Available
2.3.0, 2.3.3, 3.1.1
I am using Hive 2.3.3.
According to docs (https://cwiki.apache.org/confluence/display/Hive/Locking), they are ephemeral. But in the Zookeeper and Hive source Code, they seemed to be non-ephemeral.
I ran the following query in Hive.
lock table discovery.defaultns
When I see the lock in zookeeper, it doesn't look like ephemeral node.
[zk: localhost:2181(CONNECTED) 55] get /hive_zookeeper_namespace/discovery/defaultns/LOCK-EXCLUSIVE-0000000000
hive_20181112191555_d6640955-2806-4fa7-9e52-30d04c377a04:1542030355565:EXPLICIT:lock table discovery.defaultns exclusive:10.33.222.139
cZxid = 0x2400296808
ctime = Mon Nov 12 19:15:55 IST 2018
mZxid = 0x2400296808
mtime = Mon Nov 12 19:15:55 IST 2018
pZxid = 0x2400296808
cversion = 0
dataVersion = 0
aclVersion = 0
ephemeralOwner = 0x0
dataLength = 134
numChildren = 0
Also in the code - https://github.com/apache/hive/blob/master/ql/src/java/org/apache/hadoop/hive/ql/lockmgr/HiveTxnManagerImpl.java, the lock is KeepAlive/PERSISTENT and not EPHIMERAL. Current code is
HiveLock lck = lockMgr.lock(new HiveLockObject(tbl, lockData), mode, true);
Either the docs are misleading or code is incorrect.
If docs are correct, then it should be
HiveLock lck = lockMgr.lock(new HiveLockObject(tbl, lockData), mode, false);
The patch is the same.
Please correct me if I am wrong. This is my first ever Jira/Patch in Hive