public static LlapOutputFormatService get() throws IOException {
    Preconditions.checkState(started.get(),
        "LlapOutputFormatService must be started before invoking get");
    return INSTANCE;
  }
Responsible for sending back result set data to the connections
made by external clients via the LLAP input format.
ql/src/java/org/apache/hadoop/hive/llap/LlapOutputFormatService.java