SOLR-6570: Run SolrZkClient session watch asynchronously.

git-svn-id: https://svn.apache.org/repos/asf/lucene/dev/trunk@1640566 13f79535-47bb-0310-9956-ffa450edef68

solr/CHANGES.txt

@@ -397,6 +397,9 @@ Other Changes
 
 * SOLR-6740: Admin UI - improve Files View (steffkes)
 
+* SOLR-6570: Run SolrZkClient session watch asynchronously. 
+ (Ramkumar Aiyengar via Mark Miller)
+
 ==================  4.10.3 ==================
 
 Bug Fixes

solr/solrj/src/java/org/apache/solr/common/cloud/ConnectionManager.java

@@ -154,24 +154,9 @@ public class ConnectionManager implements Watcher {
                   throw new RuntimeException(t);
                 }
 
-                // The new event thread will call connected
-                // we just start the reconnect thread and 
-                // do nothing else
-                
                 if (onReconnect != null) {
-                  Thread thread = new Thread() {
+                  onReconnect.command();
-                    @Override
-                    public void run() {
-                      try {
-                        onReconnect.command();
-                      } catch (Exception e) {
-                        log.warn("Exception running onReconnect command", e);
-                      }
-                    }
-                  };
-                  thread.start();
                 }
-                
               }
             });
       } catch (Exception e) {

solr/solrj/src/java/org/apache/solr/common/cloud/SolrZkClient.java

@@ -144,7 +144,7 @@ public class SolrZkClient implements Closeable {
         + zkServerAddress, this, zkServerAddress, strat, onReconnect, beforeReconnect);
 
     try {
-      strat.connect(zkServerAddress, zkClientTimeout, connManager,
+      strat.connect(zkServerAddress, zkClientTimeout, wrapWatcher(connManager),
           new ZkUpdate() {
             @Override
             public void update(SolrZooKeeper zooKeeper) {