Milind Takawale created DRILL-6090: -------------------------------------- Summary: While connecting to drill-bits using JDBC Driver through Zookeeper, a lot of "Curator-Framework-0" threads are created if connection to drill-bit is not successful(no drill-bits are up/reachable) Key: DRILL-6090 URL: https://issues.apache.org/jira/browse/DRILL-6090 Project: Apache Drill Issue Type: Bug Components: Client - JDBC Affects Versions: 1.12.0 Environment: Centos 65, Java 7, Drill JDBC 1.12.0 Reporter: Milind Takawale Fix For: 1.12.0
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. -- This message was sent by Atlassian JIRA (v7.6.3#76005)