diff --git a/client-spark/spark-3/src/main/scala/org/apache/spark/shuffle/celeborn/CelebornShuffleReader.scala b/client-spark/spark-3/src/main/scala/org/apache/spark/shuffle/celeborn/CelebornShuffleReader.scala
index 2113fec05f..c7a5b57b8f 100644
--- a/client-spark/spark-3/src/main/scala/org/apache/spark/shuffle/celeborn/CelebornShuffleReader.scala
+++ b/client-spark/spark-3/src/main/scala/org/apache/spark/shuffle/celeborn/CelebornShuffleReader.scala
@@ -261,6 +261,7 @@ class CelebornShuffleReader[K, C](
       if (handle.numMappers > 0) {
         val startFetchWait = System.nanoTime()
         var inputStream: CelebornInputStream = streams.get(partitionId)
+        // todo bug fix:  split后，fetch时inputStream一直为空
         while (inputStream == null) {
           if (exceptionRef.get() != null) {
             exceptionRef.get() match {
diff --git a/client/src/main/scala/org/apache/celeborn/client/LifecycleManager.scala b/client/src/main/scala/org/apache/celeborn/client/LifecycleManager.scala
index bbfcc2e0ed..6642d9df0a 100644
--- a/client/src/main/scala/org/apache/celeborn/client/LifecycleManager.scala
+++ b/client/src/main/scala/org/apache/celeborn/client/LifecycleManager.scala
@@ -650,9 +650,10 @@ class LifecycleManager(val appUniqueId: String, val conf: CelebornConf) extends
     }
 
     // First, request to get allocated slots from Primary
-    val numGroupTask = math.ceil(numMappers.toDouble / groupMapTaskGroupSize).toInt
+    var numGroupTask = 1
     var groupNumPartitions = numPartitions
     if (partitionType.getValue.equals(PartitionType.REDUCE.getValue) && groupMapTaskEnabled) {
+      numGroupTask = math.ceil(numMappers.toDouble / groupMapTaskGroupSize).toInt
       groupNumPartitions = numPartitions * numGroupTask
     }