diff --git a/hudi-client/hudi-client-common/src/main/java/org/apache/hudi/io/IOUtils.java b/hudi-client/hudi-client-common/src/main/java/org/apache/hudi/io/IOUtils.java
index 6215df54b2609..6ba6721d9b5c6 100644
--- a/hudi-client/hudi-client-common/src/main/java/org/apache/hudi/io/IOUtils.java
+++ b/hudi-client/hudi-client-common/src/main/java/org/apache/hudi/io/IOUtils.java
@@ -32,20 +32,24 @@
 
 public class IOUtils {
   /**
-   * Dynamic calculation of max memory to use for for spillable map. user.available.memory = executor.memory *
-   * (1 - memory.fraction) spillable.available.memory = user.available.memory * hoodie.memory.fraction. Anytime
-   * the engine memory fractions/total memory is changed, the memory used for spillable map changes
-   * accordingly
+   * Dynamic calculation of max memory to use for spillable map. There is always more than one task
+   * running on a executor and the each task maintains a spillable map.
+   * user.available.memory = executor.memory * (1 - memory.fraction)
+   * spillable.available.memory = user.available.memory * hoodie.memory.fraction / executor.cores.
+   * Anytime the engine memory fractions/total memory is changed, the memory used for spillable map
+   * changes accordingly.
    */
   public static long getMaxMemoryAllowedForMerge(TaskContextSupplier context, String maxMemoryFraction) {
     Option<String> totalMemoryOpt = context.getProperty(EngineProperty.TOTAL_MEMORY_AVAILABLE);
     Option<String> memoryFractionOpt = context.getProperty(EngineProperty.MEMORY_FRACTION_IN_USE);
+    Option<String> totalCoresOpt = context.getProperty(EngineProperty.TOTAL_CORES_PER_EXECUTOR);
 
-    if (totalMemoryOpt.isPresent() && memoryFractionOpt.isPresent()) {
+    if (totalMemoryOpt.isPresent() && memoryFractionOpt.isPresent() && totalCoresOpt.isPresent()) {
       long executorMemoryInBytes = Long.parseLong(totalMemoryOpt.get());
       double memoryFraction = Double.parseDouble(memoryFractionOpt.get());
       double maxMemoryFractionForMerge = Double.parseDouble(maxMemoryFraction);
-      double userAvailableMemory = executorMemoryInBytes * (1 - memoryFraction);
+      long executorCores = Long.parseLong(totalCoresOpt.get());
+      double userAvailableMemory = executorMemoryInBytes * (1 - memoryFraction) / executorCores;
       long maxMemoryForMerge = (long) Math.floor(userAvailableMemory * maxMemoryFractionForMerge);
       return Math.max(DEFAULT_MIN_MEMORY_FOR_SPILLABLE_MAP_IN_BYTES, maxMemoryForMerge);
     } else {
diff --git a/hudi-client/hudi-spark-client/src/main/java/org/apache/hudi/client/SparkTaskContextSupplier.java b/hudi-client/hudi-spark-client/src/main/java/org/apache/hudi/client/SparkTaskContextSupplier.java
index 6397386b5348a..d118f0ead8d8e 100644
--- a/hudi-client/hudi-spark-client/src/main/java/org/apache/hudi/client/SparkTaskContextSupplier.java
+++ b/hudi-client/hudi-spark-client/src/main/java/org/apache/hudi/client/SparkTaskContextSupplier.java
@@ -78,6 +78,14 @@ public Option<String> getProperty(EngineProperty prop) {
             .get(SPARK_EXECUTOR_MEMORY_FRACTION_PROP, DEFAULT_SPARK_EXECUTOR_MEMORY_FRACTION));
       }
       return Option.empty();
+    } else if (prop == EngineProperty.TOTAL_CORES_PER_EXECUTOR) {
+      final String DEFAULT_SPARK_EXECUTOR_CORES = "1";
+      final String SPARK_EXECUTOR_EXECUTOR_CORES_PROP = "spark.executor.cores";
+      if (SparkEnv.get() != null) {
+        return Option.ofNullable(SparkEnv.get().conf()
+            .get(SPARK_EXECUTOR_EXECUTOR_CORES_PROP, DEFAULT_SPARK_EXECUTOR_CORES));
+      }
+      return Option.empty();
     }
     throw new HoodieException("Unknown engine property :" + prop);
   }
diff --git a/hudi-common/src/main/java/org/apache/hudi/common/engine/EngineProperty.java b/hudi-common/src/main/java/org/apache/hudi/common/engine/EngineProperty.java
index df2f3bf6fca76..5e9a516ec4f81 100644
--- a/hudi-common/src/main/java/org/apache/hudi/common/engine/EngineProperty.java
+++ b/hudi-common/src/main/java/org/apache/hudi/common/engine/EngineProperty.java
@@ -26,8 +26,9 @@ public enum EngineProperty {
   EMBEDDED_SERVER_HOST,
   // Pool/queue to use to run compaction.
   COMPACTION_POOL_NAME,
+  TOTAL_CORES_PER_EXECUTOR,
   // Amount of total memory available to each engine executor
   TOTAL_MEMORY_AVAILABLE,
   // Fraction of that memory, that is already in use by the engine
-  MEMORY_FRACTION_IN_USE,
+  MEMORY_FRACTION_IN_USE
 }