private boolean isTez(HiveConf conf){
    return HiveConf.getVar(conf, HiveConf.ConfVars.HIVE_EXECUTION_ENGINE).equalsIgnoreCase(
        ExecutionMode.TEZ.name());
  }
Set to true to cause all transactions to be rolled back, until set back to false.
itests/hive-unit/src/test/java/org/apache/hadoop/hive/ql/txn/compactor/TestMmCompactorOnTez.java