Fixes testSnapshotShutdownProgressTracker (#135416)

Reorders the test to avoid a race condition due to one snapshot
thread becoming blocked

Relates: 134620

muted-tests.yml

@@ -452,9 +452,6 @@ tests:
 - class: org.elasticsearch.simdvec.ESVectorUtilTests
   method: testSoarDistance
   issue: https://github.com/elastic/elasticsearch/issues/135139
-- class: org.elasticsearch.snapshots.SnapshotShutdownIT
-  method: testSnapshotShutdownProgressTracker
-  issue: https://github.com/elastic/elasticsearch/issues/134620
 - class: org.elasticsearch.upgrades.TextRollingUpgradeIT
   method: testIndexing {upgradedNodes=1}
   issue: https://github.com/elastic/elasticsearch/issues/135236

server/src/internalClusterTest/java/org/elasticsearch/snapshots/SnapshotShutdownIT.java

@@ -488,6 +488,7 @@ public class SnapshotShutdownIT extends AbstractSnapshotIntegTestCase {
         final var otherNode = internalCluster().startDataOnlyNode();
         final var otherIndex = randomIdentifier();
         createIndexWithContent(otherIndex, indexSettings(numShards, 0).put(REQUIRE_NODE_NAME_SETTING, otherNode).build());
+        indexAllShardsToAnEqualOrGreaterMinimumSize(otherIndex, ByteSizeValue.of(2, ByteSizeUnit.KB).getBytes());
         blockDataNode(repoName, otherNode);
 
         final var nodeForRemoval = internalCluster().startDataOnlyNode(
@@ -498,6 +499,7 @@ public class SnapshotShutdownIT extends AbstractSnapshotIntegTestCase {
         final var indexName = randomIdentifier();
         createIndexWithContent(indexName, indexSettings(numShards, 0).put(REQUIRE_NODE_NAME_SETTING, nodeForRemoval).build());
         indexAllShardsToAnEqualOrGreaterMinimumSize(indexName, ByteSizeValue.of(2, ByteSizeUnit.KB).getBytes());
+        logger.info("---> nodeForRemovalId: " + nodeForRemovalId + ", numShards: " + numShards);
 
         // Start the snapshot with blocking in place on the data node not to allow shard snapshots to finish yet.
         final var clusterService = internalCluster().getCurrentMasterNodeInstance(ClusterService.class);
@@ -507,7 +509,21 @@ public class SnapshotShutdownIT extends AbstractSnapshotIntegTestCase {
 
         waitForBlock(otherNode, repoName);
 
-        logger.info("---> nodeForRemovalId: " + nodeForRemovalId + ", numShards: " + numShards);
+        // Block on the master when a shard snapshot request comes in, until we can verify that the Tracker saw the outgoing request.
+        final CountDownLatch snapshotStatusUpdateLatch = new CountDownLatch(1);
+        final var masterTransportService = MockTransportService.getInstance(internalCluster().getMasterName());
+        masterTransportService.addRequestHandlingBehavior(
+            SnapshotsService.UPDATE_SNAPSHOT_STATUS_ACTION_NAME,
+            (handler, request, channel, task) -> masterTransportService.getThreadPool().generic().execute(() -> {
+                safeAwait(snapshotStatusUpdateLatch);
+                try {
+                    handler.messageReceived(request, channel, task);
+                } catch (Exception e) {
+                    fail(e);
+                }
+            })
+        );
+
         mockLog.addExpectation(
             new MockLog.SeenEventExpectation(
                 "SnapshotShutdownProgressTracker start log message",
@@ -555,21 +571,6 @@ public class SnapshotShutdownIT extends AbstractSnapshotIntegTestCase {
         mockLog.awaitAllExpectationsMatched();
         resetMockLog();
 
-        // Block on the master when a shard snapshot request comes in, until we can verify that the Tracker saw the outgoing request.
-        final CountDownLatch snapshotStatusUpdateLatch = new CountDownLatch(1);
-        final var masterTransportService = MockTransportService.getInstance(internalCluster().getMasterName());
-        masterTransportService.addRequestHandlingBehavior(
-            SnapshotsService.UPDATE_SNAPSHOT_STATUS_ACTION_NAME,
-            (handler, request, channel, task) -> masterTransportService.getThreadPool().generic().execute(() -> {
-                safeAwait(snapshotStatusUpdateLatch);
-                try {
-                    handler.messageReceived(request, channel, task);
-                } catch (Exception e) {
-                    fail(e);
-                }
-            })
-        );
-
         mockLog.addExpectation(
             new MockLog.SeenEventExpectation(
                 "SnapshotShutdownProgressTracker shard snapshot has paused log message",