Fix flakiness of RemoteRestoreSnapshotIT.testClusterManagerFailoverDuringSnapshotCreation (#17589)

Signed-off-by: Igonin <[email protected]>
Co-authored-by: Igonin <[email protected]>
Co-authored-by: Benny Goerzig <[email protected]>
Co-authored-by: Karsten Schnitter <[email protected]>
Co-authored-by: Kai Sternad <[email protected]>

Author: 5 people

Diff for: server/src/internalClusterTest/java/org/opensearch/remotestore/RemoteRestoreSnapshotIT.java

@@ -68,7 +68,9 @@
 import java.util.concurrent.CountDownLatch;
 import java.util.concurrent.ExecutionException;
 import java.util.concurrent.TimeUnit;
+import java.util.concurrent.atomic.AtomicBoolean;
 import java.util.concurrent.atomic.AtomicLong;
+import java.util.concurrent.atomic.AtomicReference;
 import java.util.stream.Collectors;
 import java.util.stream.Stream;
 
@@ -1448,9 +1450,8 @@ public void testClusterManagerFailoverDuringSnapshotCreation() throws Exception
 
         ensureStableCluster(4, internalCluster().getClusterManagerName());
 
-        final SnapshotInfo[] snapshotInfo = new SnapshotInfo[1];
-        final Boolean[] snapshotFailed = new Boolean[1];
-        snapshotFailed[0] = false;
+        final AtomicReference<SnapshotInfo> snapshotInfoRef = new AtomicReference<>();
+        final AtomicBoolean snapshotFailed = new AtomicBoolean(false);
         Thread snapshotThread = new Thread(() -> {
             try {
                 // Start snapshot creation
@@ -1459,10 +1460,10 @@ public void testClusterManagerFailoverDuringSnapshotCreation() throws Exception
                     .prepareCreateSnapshot(snapshotRepoName, snapshotName1)
                     .setWaitForCompletion(true)
                     .get();
-                snapshotInfo[0] = createSnapshotResponse.getSnapshotInfo();
+                snapshotInfoRef.set(createSnapshotResponse.getSnapshotInfo());
 
             } catch (Exception e) {
-                snapshotFailed[0] = true;
+                snapshotFailed.set(true);
             }
         });
         snapshotThread.start();
@@ -1482,10 +1483,11 @@ public void testClusterManagerFailoverDuringSnapshotCreation() throws Exception
         repository.getRepositoryData(repositoryDataPlainActionFuture);
 
         RepositoryData repositoryData = repositoryDataPlainActionFuture.get();
-        if (snapshotFailed[0]) {
-            assertFalse(repositoryData.getSnapshotIds().contains(snapshotInfo[0].snapshotId()));
+        SnapshotInfo snapshotInfo = snapshotInfoRef.get();
+        if (snapshotFailed.get()) {
+            assertTrue(repositoryData.getSnapshotIds().isEmpty());
         } else {
-            assertTrue(repositoryData.getSnapshotIds().contains(snapshotInfo[0].snapshotId()));
+            assertTrue(repositoryData.getSnapshotIds().contains(snapshotInfo.snapshotId()));
         }
     }