1 files changed, 17 insertions, 8 deletions
diff --git a/core/src/test/scala/org/apache/spark/network/netty/NettyBlockTransferServiceSuite.scala b/core/src/test/scala/org/apache/spark/network/netty/NettyBlockTransferServiceSuite.scala
index f3c156e4f7..e7df7cb419 100644
--- a/core/src/test/scala/org/apache/spark/network/netty/NettyBlockTransferServiceSuite.scala
+++ b/core/src/test/scala/org/apache/spark/network/netty/NettyBlockTransferServiceSuite.scala
@@ -17,6 +17,8 @@
 
 package org.apache.spark.network.netty
 
+import scala.util.Random
+
 import org.mockito.Mockito.mock
 import org.scalatest._
 
@@ -59,19 +61,26 @@ class NettyBlockTransferServiceSuite
   }
 
   test("can bind to a specific port") {
-    val port = 17634
+    val port = 17634 + Random.nextInt(10000)
+    logInfo("random port for test: " + port)
     service0 = createService(port)
-    service0.port should be >= port
-    service0.port should be <= (port + 10) // avoid testing equality in case of simultaneous tests
+    verifyServicePort(expectedPort = port, actualPort = service0.port)
   }
 
   test("can bind to a specific port twice and the second increments") {
-    val port = 17634
+    val port = 17634 + Random.nextInt(10000)
+    logInfo("random port for test: " + port)
     service0 = createService(port)
-    service1 = createService(port)
-    service0.port should be >= port
-    service0.port should be <= (port + 10)
-    service1.port should be (service0.port + 1)
+    verifyServicePort(expectedPort = port, actualPort = service0.port)
+    service1 = createService(service0.port)
+    // `service0.port` is occupied, so `service1.port` should not be `service0.port`
+    verifyServicePort(expectedPort = service0.port + 1, actualPort = service1.port)
+  }
+
+  private def verifyServicePort(expectedPort: Int, actualPort: Int): Unit = {
+    actualPort should be >= expectedPort
+    // avoid testing equality in case of simultaneous tests
+    actualPort should be <= (expectedPort + 10)
   }
 
   private def createService(port: Int): NettyBlockTransferService = {