diff --git a/core/src/main/java/com/taobao/arthas/core/shell/session/impl/SessionManagerImpl.java b/core/src/main/java/com/taobao/arthas/core/shell/session/impl/SessionManagerImpl.java
index c3800ce5b..8c65b2bf8 100644
--- a/core/src/main/java/com/taobao/arthas/core/shell/session/impl/SessionManagerImpl.java
+++ b/core/src/main/java/com/taobao/arthas/core/shell/session/impl/SessionManagerImpl.java
@@ -90,8 +90,10 @@ public class SessionManagerImpl implements SessionManager {
         ArrayList<Session> sessions = new ArrayList<Session>(this.sessions.values());
         for (Session session : sessions) {
             SharingResultDistributor resultDistributor = session.getResultDistributor();
-            resultDistributor.appendResult(new MessageModel("arthas server is going to shutdown."));
-            resultDistributor.close();
+            if (resultDistributor != null) {
+                resultDistributor.appendResult(new MessageModel("arthas server is going to shutdown."));
+                resultDistributor.close();
+            }
             logger.info("Removing session before shutdown: {}, last access time: {}", session.getSessionId(), session.getLastAccessTime());
             this.removeSession(session.getSessionId());
         }
@@ -142,7 +144,10 @@ public class SessionManagerImpl implements SessionManager {
             }
             long timeOutInMinutes = sessionTimeoutMillis / 1000 / 60;
             String reason = "session is inactive for " + timeOutInMinutes + " min(s).";
-            session.getResultDistributor().appendResult(new MessageModel(reason));
+            SharingResultDistributor resultDistributor = session.getResultDistributor();
+            if (resultDistributor != null) {
+                resultDistributor.appendResult(new MessageModel(reason));
+            }
             this.removeSession(session.getSessionId());
             logger.info("Removing inactive session: {}, last access time: {}", session.getSessionId(), session.getLastAccessTime());
         }
@@ -153,7 +158,7 @@ public class SessionManagerImpl implements SessionManager {
      */
     public void evictConsumers(Session session) {
         SharingResultDistributor distributor = session.getResultDistributor();
-        if (distributor instanceof SharingResultDistributor) {
+        if (distributor != null && distributor instanceof SharingResultDistributor) {
             SharingResultDistributor sharingResultDistributor = (SharingResultDistributor) distributor;
             List<ResultConsumer> consumers = sharingResultDistributor.getConsumers();
             //remove inactive consumer from session directly
diff --git a/core/src/main/java/com/taobao/arthas/core/shell/term/impl/http/api/HttpApiHandler.java b/core/src/main/java/com/taobao/arthas/core/shell/term/impl/http/api/HttpApiHandler.java
index a5d1ee3a0..158e67791 100644
--- a/core/src/main/java/com/taobao/arthas/core/shell/term/impl/http/api/HttpApiHandler.java
+++ b/core/src/main/java/com/taobao/arthas/core/shell/term/impl/http/api/HttpApiHandler.java
@@ -321,7 +321,10 @@ public class HttpApiHandler {
         ResultConsumer resultConsumer = new ResultConsumerImpl();
         //disable input and interrupt
         resultConsumer.appendResult(new InputStatusModel(InputStatus.DISABLED));
-        session.getResultDistributor().addConsumer(resultConsumer);
+        SharingResultDistributor resultDistributor = session.getResultDistributor();
+        if (resultDistributor != null) {
+            resultDistributor.addConsumer(resultConsumer);
+        }
 
         ApiResponse response = new ApiResponse();
         response.setSessionId(session.getSessionId())
@@ -486,7 +489,10 @@ public class HttpApiHandler {
             //add command before exec job
             CommandRequestModel commandRequestModel = new CommandRequestModel(commandLine, response.getState());
             commandRequestModel.setJobId(job.id());
-            session.getResultDistributor().appendResult(commandRequestModel);
+            SharingResultDistributor resultDistributor = session.getResultDistributor();
+            if (resultDistributor != null) {
+                resultDistributor.appendResult(commandRequestModel);
+            }
             session.setForegroundJob(job);
             updateSessionInputStatus(session, InputStatus.ALLOW_INTERRUPT);
 
@@ -534,7 +540,11 @@ public class HttpApiHandler {
         if (StringUtils.isBlank(consumerId)) {
             throw new ApiException("'consumerId' is required");
         }
-        ResultConsumer consumer = session.getResultDistributor().getConsumer(consumerId);
+        ResultConsumer consumer = null;
+        SharingResultDistributor resultDistributor = session.getResultDistributor();
+        if (resultDistributor != null) {
+            consumer = resultDistributor.getConsumer(consumerId);
+        }
         if (consumer == null) {
             throw new ApiException("consumer not found: " + consumerId);
         }