[HBASE-16389] Thread leak in CoprocessorHost#getTable(TableName) API

• Type: Bug
• Status: Resolved
• Priority: Major
• Resolution: Fixed
• Fix Version/s: 2.0.0
• Hadoop Flags: Reviewed
• Assignee: Ankit Singhal
• Reporter: Ankit Singhal
• Created: 10/Aug/16 15:11
• Updated: 11/Aug/16 06:11
• Resolved: 11/Aug/16 03:02

Description

There is a thread leak in below method, we are creating a default pool while calling

@Override
    public HTableInterface getTable(TableName tableName) throws IOException {
      return this.getTable(tableName, HTable.getDefaultExecutor(getConfiguration()));
    }

which will never be shutdown because in HTable, we are setting this.cleanupPoolOnClose to false

 @InterfaceAudience.Private
  public HTable(TableName tableName, final ClusterConnection connection,
      final TableConfiguration tableConfig,
      final RpcRetryingCallerFactory rpcCallerFactory,
      final RpcControllerFactory rpcControllerFactory,
      final ExecutorService pool) throws IOException {
    if (connection == null || connection.isClosed()) {
      throw new IllegalArgumentException("Connection is null or closed.");
    }
    this.tableName = tableName;
    this.cleanupConnectionOnClose = false;
    this.connection = connection;
    this.configuration = connection.getConfiguration();
    this.tableConfiguration = tableConfig;
    this.pool = pool;
    if (pool == null) {
      this.pool = getDefaultExecutor(this.configuration);
      this.cleanupPoolOnClose = true;
    } else {
      this.cleanupPoolOnClose = false;
    }

resulted in pool to stay forever ,which eventually can lead other processes or the same process to starve for a threads.