@Override
      public void run() {
        if (EXECUTOR != null) {
          EXECUTOR.shutdownNow();
        }
      }
Through this class the caller (typically HS2) can request eviction of buffers from LLAP cache by specifying a DB,
table or partition name/(value). Request sending is implemented here.
ql/src/java/org/apache/hadoop/hive/llap/ProactiveEviction.java