diff --git a/redisson/src/main/java/org/redisson/connection/ReplicatedConnectionManager.java b/redisson/src/main/java/org/redisson/connection/ReplicatedConnectionManager.java
index 792c01484..329ff31fa 100644
--- a/redisson/src/main/java/org/redisson/connection/ReplicatedConnectionManager.java
+++ b/redisson/src/main/java/org/redisson/connection/ReplicatedConnectionManager.java
@@ -84,6 +84,7 @@ public class ReplicatedConnectionManager extends MasterSlaveConnectionManager {
             Role role = Role.valueOf(connection.sync(RedisCommands.INFO_REPLICATION).get(ROLE_KEY));
             if (Role.master.equals(role)) {
                 if (currentMaster.get() != null) {
+                    stopThreads();
                     throw new RedisException("Multiple masters detected");
                 }
                 currentMaster.set(addr);
@@ -96,6 +97,7 @@ public class ReplicatedConnectionManager extends MasterSlaveConnectionManager {
         }
 
         if (currentMaster.get() == null) {
+            stopThreads();
             throw new RedisConnectionException("Can't connect to servers!");
         }
 
diff --git a/redisson/src/main/java/org/redisson/connection/SentinelConnectionManager.java b/redisson/src/main/java/org/redisson/connection/SentinelConnectionManager.java
index bd13f9462..4e9c3588c 100755
--- a/redisson/src/main/java/org/redisson/connection/SentinelConnectionManager.java
+++ b/redisson/src/main/java/org/redisson/connection/SentinelConnectionManager.java
@@ -71,6 +71,10 @@ public class SentinelConnectionManager extends MasterSlaveConnectionManager {
         this.config = create(cfg);
         initTimer(this.config);
 
+        if (cfg.getMasterName() == null) {
+            throw new IllegalArgumentException("masterName parameter is not defined!");
+        }
+        
         for (URI addr : cfg.getSentinelAddresses()) {
             RedisClient client = createClient(NodeType.SENTINEL, addr, this.config.getConnectTimeout(), this.config.getRetryInterval() * this.config.getRetryAttempts());
             try {
@@ -119,6 +123,7 @@ public class SentinelConnectionManager extends MasterSlaveConnectionManager {
         }
 
         if (currentMaster.get() == null) {
+            stopThreads();
             throw new RedisConnectionException("Can't connect to servers!");
         }
         init(this.config);