diff --git a/dolphinscheduler-server/src/main/java/org/apache/dolphinscheduler/server/zk/ZKMasterClient.java b/dolphinscheduler-server/src/main/java/org/apache/dolphinscheduler/server/zk/ZKMasterClient.java
index 69aecee444..1b807a7278 100644
--- a/dolphinscheduler-server/src/main/java/org/apache/dolphinscheduler/server/zk/ZKMasterClient.java
+++ b/dolphinscheduler-server/src/main/java/org/apache/dolphinscheduler/server/zk/ZKMasterClient.java
@@ -335,6 +335,9 @@ public class ZKMasterClient extends AbstractZKClient {
 
 		//updateProcessInstance host is null and insert into command
 		for(ProcessInstance processInstance : needFailoverProcessInstanceList){
+			if(Constants.NULL.equals(processInstance.getHost()) ){
+			    continue;
+			}
 			processService.processNeedFailoverProcessInstances(processInstance);
 		}
 
diff --git a/dolphinscheduler-service/src/main/java/org/apache/dolphinscheduler/service/process/ProcessService.java b/dolphinscheduler-service/src/main/java/org/apache/dolphinscheduler/service/process/ProcessService.java
index 36e2b60d18..0bab35a821 100644
--- a/dolphinscheduler-service/src/main/java/org/apache/dolphinscheduler/service/process/ProcessService.java
+++ b/dolphinscheduler-service/src/main/java/org/apache/dolphinscheduler/service/process/ProcessService.java
@@ -121,10 +121,6 @@ public class ProcessService {
             logger.info("there is not enough thread for this command: {}", command);
             return setWaitingThreadProcess(command, processInstance);
         }
-        if (processInstance.getCommandType().equals(CommandType.RECOVER_TOLERANCE_FAULT_PROCESS)){
-            delCommandByid(command.getId());
-            return null;
-        }
         processInstance.setCommandType(command.getCommandType());
         processInstance.addHistoryCmd(command.getCommandType());
         saveProcessInstance(processInstance);
@@ -1484,7 +1480,7 @@ public class ProcessService {
     @Transactional(rollbackFor = Exception.class)
     public void processNeedFailoverProcessInstances(ProcessInstance processInstance){
         //1 update processInstance host is null
-        processInstance.setHost("null");
+        processInstance.setHost(Constants.NULL);
         processInstanceMapper.updateById(processInstance);
 
         //2 insert into recover command
diff --git a/dolphinscheduler-service/src/main/java/org/apache/dolphinscheduler/service/zk/AbstractZKClient.java b/dolphinscheduler-service/src/main/java/org/apache/dolphinscheduler/service/zk/AbstractZKClient.java
index acbbe76188..2960969d86 100644
--- a/dolphinscheduler-service/src/main/java/org/apache/dolphinscheduler/service/zk/AbstractZKClient.java
+++ b/dolphinscheduler-service/src/main/java/org/apache/dolphinscheduler/service/zk/AbstractZKClient.java
@@ -125,12 +125,16 @@ public abstract class AbstractZKClient extends ZookeeperCachedOperator {
 		List<Server> masterServers = new ArrayList<>();
 		for (Map.Entry<String, String> entry : masterMap.entrySet()) {
 			Server masterServer = ResInfo.parseHeartbeatForZKInfo(entry.getValue());
+			if(masterServer == null){
+				continue;
+			}
 			String key = entry.getKey();
 			masterServer.setZkDirectory(parentPath + "/"+ key);
 			//set host and port
 			String[] hostAndPort=key.split(COLON);
 			String[] hosts=hostAndPort[0].split(DIVISION_STRING);
-			masterServer.setHost(hosts[hosts.length-1]);// fetch the last one
+			// fetch the last one
+			masterServer.setHost(hosts[hosts.length-1]);
 			masterServer.setPort(Integer.parseInt(hostAndPort[1]));
 			masterServers.add(masterServer);
 		}