GitHub user milindt opened a pull request:
https://github.com/apache/drill/pull/1094
DRILL-6090: While connecting to drill-bits using JDBC Driver through â¦
â¦Zookeeper, a lot of "Curator-Framework-0" threads are created if
connection to drill-bit is not successful(no drill-bits are up/reachable)
I am using Drill JDBC driver 1.12.0 to connect to MapR-DB. I am finding the
available drill-bits using Zookeepers. When drill-bits are not up or not
reachable, the connection is failed with exception: "Failure in connecting to
Drill: oadd.org.apache.drill.exec.rpc.RpcException: Failure setting up ZK for
client", which is expected, but number of threads created by
ZKClusterCoordinator just keeps on increasing.
Steps to reproduce the issue
Setup a connection with a drill-bit using Apache Drill JDBC driver 1.12.0
through Zookeeper hosts(port 5181)
Now stop the drill-bit services or block the drill-bit IPs using iptable
rules
Truncate catalina logs
Try to connect to the drill-bit/hit a code path that requires connection to
drill-bits.
Take thread dump using kill -QUIT <java process id>
grep -c "Curator-Framework-0" catalina.out
Observe that the curator framework thread just keep on accumulating
RCA:
ZKClusterCoordinator creates curator threads in the constructor
ZKClusterCoordinator is instantiated by DrillClient.connect
DrillClient.connect is called in DrillConnectionImpl constructor
Fix:
Call DrillConnectionImpl .cleanup() from all the catch blocks in the
DrillConnectionImpl constructor.
[JIRA link](https://issues.apache.org/jira/browse/DRILL-6090)
If this fix is accepted, will there be a release from this branch(1.12.0)?
A release with minor version may be.
You can merge this pull request into a Git repository by running:
$ git pull https://github.com/milindt/drill 1.12.0
Alternatively you can review and apply these changes as the patch at:
https://github.com/apache/drill/pull/1094.patch
To close this pull request, make a commit to your master/trunk branch
with (at least) the following in the commit message:
This closes #1094
----
----
---
