diff --git a/server/src/main/java/com/exacaster/lighter/spark/SubmitParams.java b/server/src/main/java/com/exacaster/lighter/spark/SubmitParams.java
index f4bad376..edddca64 100644
--- a/server/src/main/java/com/exacaster/lighter/spark/SubmitParams.java
+++ b/server/src/main/java/com/exacaster/lighter/spark/SubmitParams.java
@@ -89,7 +89,7 @@ public Integer getNumExecutors() {
     }
 
     public Integer getExecutorCores() {
-        return ofNullable(executorCores).orElse(2);
+        return ofNullable(executorCores).orElse(1);
     }
 
     public String getExecutorMemory() {
@@ -97,7 +97,7 @@ public String getExecutorMemory() {
     }
 
     public Integer getDriverCores() {
-        return ofNullable(driverCores).orElse(2);
+        return ofNullable(driverCores).orElse(1);
     }
 
     public String getDriverMemory() {
diff --git a/server/src/test/groovy/com/exacaster/lighter/spark/SparkAppTest.groovy b/server/src/test/groovy/com/exacaster/lighter/spark/SparkAppTest.groovy
index 8b72d025..c83af0ec 100644
--- a/server/src/test/groovy/com/exacaster/lighter/spark/SparkAppTest.groovy
+++ b/server/src/test/groovy/com/exacaster/lighter/spark/SparkAppTest.groovy
@@ -27,7 +27,7 @@ class SparkAppTest extends Specification {
         result == [
                 "spark.executor.memory":"1000M",
                 "spark.driver.memory":"1000M",
-                "spark.executor.cores":"2",
+                "spark.executor.cores":"1",
                 "spark.driver.cores":"1",
                 "spark.executor.instances":"0",
                 "spark.kubernetes.driverEnv.TEST1":"test1"