Hive query may be disturbed by other concurrent queries

[xielong]

Hive storages DB information in ThreadLocal, and quartz uses the SimpleThreadPool. If HQL accesses the different Hive DB, which may lead to the exception "table db.xx not found".

Relevant code:

Hive Version: Hive 0.9
Clas Name:org.apache.hadoop.hive.ql.metadata.Hive

private static ThreadLocal hiveDB = new ThreadLocal() {
@OverRide
protected synchronized Object initialValue() {
return null;
}

@Override
public synchronized void remove() {
  if (this.get() != null) {
    ((Hive) this.get()).close();
  }
  super.remove();
}

};