GEODE-8071: Prevent Test Flakiness (apache#5676)

Different versions of the embedded Jetty server can launch non-daemon threads, so the fix implies preventing any flakiness by just checking for the thread we're interested in.
kekerzzZ · Oct 27, 2020 · 38ed638 · 38ed638
1 parent d9c859b
commit 38ed638
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Showing 2 changed files with 14 additions and 17 deletions.
diff --git a/...va/org/apache/geode/management/internal/cli/commands/RebalanceCommandDistributedTest.java b/...va/org/apache/geode/management/internal/cli/commands/RebalanceCommandDistributedTest.java
@@ -183,25 +183,18 @@ public void testRebalanceResultOutputMemberCount() {
 
   /**
    * See GEODE-8071.
-   * The test asserts that the amount of non-daemon threads on the locator VM remains constant
-   * before and after executing the re-balance command.
+   * The test simply asserts that the re-balance command doesn't launch a non daemon thread
+   * during its execution.
    */
   @Test
   public void rebalanceCommandShouldNotLaunchNonDaemonThreads() {
-    long nonDaemonThreadsBeforeCommand = locator.invoke(() -> Thread.getAllStackTraces()
-        .keySet()
-        .stream()
-        .filter(thread -> !thread.isDaemon())
-        .count());
-
     gfsh.executeAndAssertThat("rebalance").statusIsSuccess();
-
-    long daemonThreadsAfterCommand = locator.invoke(() -> Thread.getAllStackTraces()
-        .keySet()
-        .stream()
-        .filter(thread -> !thread.isDaemon())
-        .count());
-
-    assertThat(daemonThreadsAfterCommand).isEqualTo(nonDaemonThreadsBeforeCommand);
+    locator.invoke(() -> {
+      assertThat(Thread.getAllStackTraces().keySet().stream()
+          .anyMatch(thread -> !thread.isDaemon()
+              && thread.getName().contains(RebalanceCommand.THREAD_NAME)))
+                  .as("Rebalance Command should not launch non daemon threads")
+                  .isFalse();
+    });
   }
 }
diff --git a/...fsh/src/main/java/org/apache/geode/management/internal/cli/commands/RebalanceCommand.java b/...fsh/src/main/java/org/apache/geode/management/internal/cli/commands/RebalanceCommand.java
@@ -30,6 +30,7 @@
 import org.springframework.shell.core.annotation.CliCommand;
 import org.springframework.shell.core.annotation.CliOption;
 
+import org.apache.geode.annotations.VisibleForTesting;
 import org.apache.geode.internal.cache.InternalCache;
 import org.apache.geode.logging.internal.executors.LoggingExecutors;
 import org.apache.geode.management.cli.CliMetaData;
@@ -46,6 +47,9 @@
 import org.apache.geode.security.ResourcePermission;
 
 public class RebalanceCommand extends GfshCommand {
+  @VisibleForTesting
+  public static String THREAD_NAME = "RebalanceCommand";
+
   @CliCommand(value = CliStrings.REBALANCE, help = CliStrings.REBALANCE__HELP)
   @CliMetaData(relatedTopic = {CliStrings.TOPIC_GEODE_DATA, CliStrings.TOPIC_GEODE_REGION})
   @ResourceOperation(resource = ResourcePermission.Resource.DATA,
@@ -62,7 +66,7 @@ public ResultModel rebalance(
           help = CliStrings.REBALANCE__SIMULATE__HELP) boolean simulate) {
 
     ExecutorService commandExecutors =
-        LoggingExecutors.newSingleThreadExecutor("RebalanceCommand", true);
+        LoggingExecutors.newSingleThreadExecutor(THREAD_NAME, true);
     List<Future<ResultModel>> commandResult = new ArrayList<>();
     ResultModel result;
     try {