[beam] branch master updated: [BEAM-7170] Fix exception when retrieving ExpansionServer port after closing

[mxm]

This is an automated email from the ASF dual-hosted git repository.

mxm pushed a commit to branch master
in repository https://gitbox.apache.org/repos/asf/beam.git


The following commit(s) were added to refs/heads/master by this push:
     new a8f4e22  [BEAM-7170] Fix exception when retrieving ExpansionServer 
port after closing
     new 7e1de51  Merge pull request #8424: [BEAM-7170] Fix exception when 
retrieving ExpansionServer port after closing
a8f4e22 is described below

commit a8f4e221cd240138df20edb1b58f69e9c37aced1
Author: Maximilian Michels <m...@apache.org>
AuthorDate: Mon Apr 29 12:36:37 2019 +0200

    [BEAM-7170] Fix exception when retrieving ExpansionServer port after closing
    
    The ExpansionServer can throw the following exception after shutdown 
because the
    port getter retrieves the port dynamically from the underlying service:
    
    ```
    java.lang.IllegalStateException: Already terminated
        at 
org.apache.beam.vendor.grpc.v1p13p1.com.google.common.base.Preconditions.checkState(Preconditions.java:444)
        at 
org.apache.beam.vendor.grpc.v1p13p1.io.grpc.internal.ServerImpl.getPort(ServerImpl.java:174)
        at 
org.apache.beam.runners.core.construction.expansion.ExpansionServer.getPort(ExpansionServer.java:66)
    ```
---
 .../construction/expansion/ExpansionServer.java    |  9 ++--
 .../expansion/ExpansionServerTest.java             | 48 ++++++++++++++++++++++
 2 files changed, 51 insertions(+), 6 deletions(-)

diff --git 
a/runners/core-construction-java/src/main/java/org/apache/beam/runners/core/construction/expansion/ExpansionServer.java
 
b/runners/core-construction-java/src/main/java/org/apache/beam/runners/core/construction/expansion/ExpansionServer.java
index d152e76..b8ec70c 100644
--- 
a/runners/core-construction-java/src/main/java/org/apache/beam/runners/core/construction/expansion/ExpansionServer.java
+++ 
b/runners/core-construction-java/src/main/java/org/apache/beam/runners/core/construction/expansion/ExpansionServer.java
@@ -38,6 +38,7 @@ public class ExpansionServer implements AutoCloseable {
   }
 
   private final String host;
+  private final int port;
   private final Server server;
   private final ExpansionService service;
 
@@ -49,11 +50,7 @@ public class ExpansionServer implements AutoCloseable {
             .addService(service)
             .build()
             .start();
-  }
-
-  /** Get the ExpansionService exposed by this {@link ExpansionServer}. */
-  public ExpansionService getService() {
-    return service;
+    this.port = server.getPort();
   }
 
   /** Get the host that this {@link ExpansionServer} is bound to. */
@@ -63,7 +60,7 @@ public class ExpansionServer implements AutoCloseable {
 
   /** Get the port that this {@link ExpansionServer} is bound to. */
   public int getPort() {
-    return server.getPort();
+    return port;
   }
 
   @Override
diff --git 
a/runners/core-construction-java/src/test/java/org/apache/beam/runners/core/construction/expansion/ExpansionServerTest.java
 
b/runners/core-construction-java/src/test/java/org/apache/beam/runners/core/construction/expansion/ExpansionServerTest.java
new file mode 100644
index 0000000..29370d9
--- /dev/null
+++ 
b/runners/core-construction-java/src/test/java/org/apache/beam/runners/core/construction/expansion/ExpansionServerTest.java
@@ -0,0 +1,48 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.apache.beam.runners.core.construction.expansion;
+
+import static org.hamcrest.MatcherAssert.assertThat;
+import static org.hamcrest.Matchers.greaterThan;
+import static org.hamcrest.core.Is.is;
+
+import org.junit.Test;
+
+/** Tests for {@link ExpansionServer}. */
+public class ExpansionServerTest {
+
+  @Test
+  public void testStartupOnFreePort() throws Exception {
+    try (ExpansionServer expansionServer =
+        ExpansionServer.create(new ExpansionService(), "localhost", 0)) {
+      assertThat(expansionServer.getHost(), is("localhost"));
+      assertThat(expansionServer.getPort(), greaterThan(0));
+    }
+  }
+
+  @Test
+  public void testHostPortAvailableAfterClose() throws Exception {
+    ExpansionServer expansionServer;
+    try (ExpansionServer expServer =
+        ExpansionServer.create(new ExpansionService(), "localhost", 0)) {
+      expansionServer = expServer;
+    }
+    assertThat(expansionServer.getHost(), is("localhost"));
+    assertThat(expansionServer.getPort(), greaterThan(0));
+  }
+}