[SPARK-15004][SQL] Remove zookeeper service discovery code in thrift-server

## What changes were proposed in this pull request?
We recently inlined Hive's thrift server code in SPARK-15004. This patch removes the code related to zookeeper service discovery, Tez, and Hive on Spark, since they are irrelevant.

## How was this patch tested?
N/A - removing dead code

Author: Reynold Xin <rxin@databricks.com>

Closes #12780 from rxin/SPARK-15004.

1 files changed, 1 insertions, 22 deletions

diff --git a/sql/hive-thriftserver/src/main/java/org/apache/hive/service/cli/session/SessionManager.java b/sql/hive-thriftserver/src/main/java/org/apache/hive/service/cli/session/SessionManager.java
index 36a30b1e28..e31570bdfb 100644
--- a/sql/hive-thriftserver/src/main/java/org/apache/hive/service/cli/session/SessionManager.java
+++ b/sql/hive-thriftserver/src/main/java/org/apache/hive/service/cli/session/SessionManager.java
@@ -288,28 +288,7 @@ public class SessionManager extends CompositeService {
     if (session == null) {
       throw new HiveSQLException("Session does not exist!");
     }
-    try {
-      session.close();
-    } finally {
-      // Shutdown HiveServer2 if it has been deregistered from ZooKeeper and has no active sessions
-      if (!(hiveServer2 == null) && (hiveConf.getBoolVar(ConfVars.HIVE_SERVER2_SUPPORT_DYNAMIC_SERVICE_DISCOVERY))
-          && (!hiveServer2.isRegisteredWithZooKeeper())) {
-        // Asynchronously shutdown this instance of HiveServer2,
-        // if there are no active client sessions
-        if (getOpenSessionCount() == 0) {
-          LOG.info("This instance of HiveServer2 has been removed from the list of server "
-              + "instances available for dynamic service discovery. "
-              + "The last client session has ended - will shutdown now.");
-          Thread shutdownThread = new Thread() {
-            @Override
-            public void run() {
-              hiveServer2.stop();
-            }
-          };
-          shutdownThread.start();
-        }
-      }
-    }
+    session.close();
   }
 
   public HiveSession getSession(SessionHandle sessionHandle) throws HiveSQLException {