diff --git a/hugegraph-core/src/main/java/com/baidu/hugegraph/backend/store/raft/RaftNode.java b/hugegraph-core/src/main/java/com/baidu/hugegraph/backend/store/raft/RaftNode.java
index 9a7b3ee978..a9edc8297a 100644
--- a/hugegraph-core/src/main/java/com/baidu/hugegraph/backend/store/raft/RaftNode.java
+++ b/hugegraph-core/src/main/java/com/baidu/hugegraph/backend/store/raft/RaftNode.java
@@ -285,6 +285,13 @@ public void onError(PeerId peer, Status status) {
             }
         }
 
+        @Override
+        public void onBusy(PeerId peer, Status status) {
+            // NOTE: Jraft itself doesn't have this callback, it's added by us
+            int count = RaftNode.this.busyCounter.incrementAndGet();
+            LOG.info("Increase busy counter: [{}]", count);
+        }
+
         private boolean isWriteBufferOverflow(Status status) {
             String expectMsg = "maybe write overflow";
             return RaftError.EINTERNAL == status.getRaftError() &&
diff --git a/hugegraph-core/src/main/java/com/baidu/hugegraph/backend/store/raft/RaftSharedContext.java b/hugegraph-core/src/main/java/com/baidu/hugegraph/backend/store/raft/RaftSharedContext.java
index e4c7f44385..56ee6c0548 100644
--- a/hugegraph-core/src/main/java/com/baidu/hugegraph/backend/store/raft/RaftSharedContext.java
+++ b/hugegraph-core/src/main/java/com/baidu/hugegraph/backend/store/raft/RaftSharedContext.java
@@ -25,9 +25,9 @@
 import java.util.List;
 import java.util.concurrent.BlockingQueue;
 import java.util.concurrent.ExecutorService;
-import java.util.concurrent.LinkedBlockingQueue;
 import java.util.concurrent.RejectedExecutionException;
 import java.util.concurrent.RejectedExecutionHandler;
+import java.util.concurrent.SynchronousQueue;
 import java.util.concurrent.ThreadPoolExecutor;
 
 import org.apache.commons.io.FileUtils;
@@ -362,7 +362,7 @@ private ExecutorService createBackendExecutor(int threads) {
     private static ExecutorService newPool(int coreThreads, int maxThreads,
                                            String name,
                                            RejectedExecutionHandler handler) {
-        BlockingQueue<Runnable> workQueue = new LinkedBlockingQueue<>();
+        BlockingQueue<Runnable> workQueue = new SynchronousQueue<>();
         return ThreadPoolUtil.newBuilder()
                              .poolName(name)
                              .enableMetric(false)
diff --git a/hugegraph-core/src/main/java/com/baidu/hugegraph/backend/store/raft/StoreStateMachine.java b/hugegraph-core/src/main/java/com/baidu/hugegraph/backend/store/raft/StoreStateMachine.java
index 2b8981015c..2689b713f4 100644
--- a/hugegraph-core/src/main/java/com/baidu/hugegraph/backend/store/raft/StoreStateMachine.java
+++ b/hugegraph-core/src/main/java/com/baidu/hugegraph/backend/store/raft/StoreStateMachine.java
@@ -21,6 +21,7 @@
 
 import java.util.ArrayList;
 import java.util.List;
+import java.util.concurrent.Future;
 
 import org.slf4j.Logger;
 
@@ -103,8 +104,11 @@ public void onApply(Iterator iter) {
         LOG.debug("Node role: {}", this.node().selfIsLeader() ?
                                    "leader" : "follower");
         StoreClosure closure = null;
+        List<Future<?>> futures = new ArrayList<>();
+        int count = 0;
         try {
             while (iter.hasNext()) {
+                count++;
                 closure = (StoreClosure) iter.done();
                 if (closure != null) {
                     // Leader just take it out from the closure
@@ -124,7 +128,7 @@ public void onApply(Iterator iter) {
                     byte[] bytes = iter.getData().array();
                     // Follower seems no way to wait future
                     // Let the backend thread do it directly
-                    this.context.backendExecutor().submit(() -> {
+                    futures.add(this.context.backendExecutor().submit(() -> {
                         BytesBuffer buffer = LZ4Util.decompress(bytes,
                                              RaftSharedContext.BLOCK_SIZE);
                         buffer.forReadWritten();
@@ -137,10 +141,15 @@ public void onApply(Iterator iter) {
                                       action, e);
                             throw new BackendException("Backend error", e);
                         }
-                    });
+                    }));
                 }
                 iter.next();
             }
+            System.out.println("futures size: " + count);
+            // Follower wait tasks finished
+            for (Future<?> future : futures) {
+                future.get();
+            }
         } catch (Throwable e) {
             LOG.error("StateMachine occured critical error", e);
             Status status = new Status(RaftError.ESTATEMACHINE,
@@ -150,6 +159,7 @@ public void onApply(Iterator iter) {
                 closure.failure(status, e);
             }
             // Will cause current node inactive
+            // TODO: rollback to correct index
             iter.setErrorAndRollback(1L, status);
         }
     }
@@ -253,6 +263,7 @@ public void onConfigurationCommitted(Configuration conf) {
 
     @Override
     public void onError(final RaftException e) {
+        // If busy, spin and wait a moment
         LOG.error("Raft error: {}", e.getMessage(), e);
     }
 }
diff --git a/hugegraph-dist/src/assembly/static/bin/raft-tools.sh b/hugegraph-dist/src/assembly/static/bin/raft-tools.sh
index aa5faa2e59..f386571e80 100755
--- a/hugegraph-dist/src/assembly/static/bin/raft-tools.sh
+++ b/hugegraph-dist/src/assembly/static/bin/raft-tools.sh
@@ -86,46 +86,38 @@ function remove_peer() {
     curl -X POST ${url}
 }
 
-while [[ $# -gt 0 ]]; do
-    case $1 in
-        # help
-        --help|-h)
-        print_usage
-        shift
-        ;;
-        # list-peers
-        --list-peers|-l)
-        list_peers $2
-        shift 2
-        ;;
-        # get-leader
-        --get-leader|-g)
-        get_leader $2
-        shift 2
-        ;;
-        # set-leader
-        --set-leader|-s)
-        set_leader $2 $3
-        shift 3
-        ;;
-        # transfer-leader
-        --transfer-leader|-t)
-        transfer_leader $2 $3
-        shift 3
-        ;;
-        # add-peer
-        --add-peer|-a)
-        add_peer $2 $3
-        shift 3
-        ;;
-        # remove-peer
-        --remove-peer|-r)
-        remove_peer $2 $3
-        shift 3
-        ;;
-        *)
-        print_usage
-        exit 0
-        ;;
-    esac
-done
+case $1 in
+    # help
+    --help|-h)
+    print_usage
+    ;;
+    # list-peers
+    --list-peers|-l)
+    list_peers $2
+    ;;
+    # get-leader
+    --get-leader|-g)
+    get_leader $2
+    ;;
+    # set-leader
+    --set-leader|-s)
+    set_leader $2 $3
+    ;;
+    # transfer-leader
+    --transfer-leader|-t)
+    transfer_leader $2 $3
+    ;;
+    # add-peer
+    --add-peer|-a)
+    add_peer $2 $3
+    ;;
+    # remove-peer
+    --remove-peer|-r)
+    remove_peer $2 $3
+    ;;
+    *)
+    print_usage
+    exit 0
+    ;;
+esac
+echo ""