Suppress lease background sync failures if stopping

server/src/main/java/org/elasticsearch/index/seqno/RetentionLeaseBackgroundSyncAction.java

@@ -44,6 +44,7 @@
 import org.elasticsearch.index.shard.ShardId;
 import org.elasticsearch.indices.IndicesService;
 import org.elasticsearch.threadpool.ThreadPool;
+import org.elasticsearch.transport.TransportException;
 import org.elasticsearch.transport.TransportService;
 
 import java.io.IOException;
@@ -113,9 +114,19 @@ public void backgroundSync(
                     ActionListener.wrap(
                             r -> {},
                             e -> {
-                                if (ExceptionsHelper.unwrap(e, AlreadyClosedException.class, IndexShardClosedException.class) == null) {
-                                    getLogger().warn(new ParameterizedMessage("{} retention lease background sync failed", shardId), e);
+                                final TransportException maybeTransport =
+                                        (TransportException) ExceptionsHelper.unwrap(e, TransportException.class);
+                                if (maybeTransport != null
+                                        && (maybeTransport.getMessage().equals("TransportService is closed stopped can't send request")
+                                        || maybeTransport.getMessage().equals("transport stopped, action: " + ACTION_NAME + "[p]"))) {
+                                    // we are likely shutting down
+                                    return;
                                 }
+                                if (ExceptionsHelper.unwrap(e, AlreadyClosedException.class, IndexShardClosedException.class) != null) {
+                                    // the shard is closed
+                                    return;
+                                }
+                                getLogger().warn(new ParameterizedMessage("{} retention lease background sync failed", shardId), e);
                             }));
         }
     }

server/src/main/java/org/elasticsearch/transport/TransportService.java

@@ -626,8 +626,13 @@ private <T extends TransportResponse> void sendRequestInternal(final Transport.C
         }
         try {
             if (lifecycle.stoppedOrClosed()) {
-                // if we are not started the exception handling will remove the RequestHolder again and calls the handler to notify
-                // the caller. It will only notify if the toStop code hasn't done the work yet.
+                /*
+                 * If we are not started the exception handling will remove the request holder again and calls the handler to notify the
+                 * caller. It will only notify if toStop hasn't done the work yet.
+                 *
+                 * Do not edit this exception message, it is currently relied upon in production code!
+                 */
+                // TODO: make a dedicated exception for a stopped transport service?
                 throw new TransportException("TransportService is closed stopped can't send request");
             }
             if (timeoutHandler != null) {

server/src/test/java/org/elasticsearch/index/seqno/RetentionLeaseBackgroundSyncActionTests.java

@@ -42,6 +42,7 @@
 import org.elasticsearch.test.transport.CapturingTransport;
 import org.elasticsearch.threadpool.TestThreadPool;
 import org.elasticsearch.threadpool.ThreadPool;
+import org.elasticsearch.transport.TransportException;
 import org.elasticsearch.transport.TransportService;
 import org.mockito.ArgumentCaptor;
 
@@ -204,9 +205,13 @@ protected void doExecute(Task task, Request request, ActionListener<ReplicationR
                     final Exception e = randomFrom(
                             new AlreadyClosedException("closed"),
                             new IndexShardClosedException(indexShard.shardId()),
+                            new TransportException(randomFrom(
+                                    "failed",
+                                    "TransportService is closed stopped can't send request",
+                                    "transport stopped, action: indices:admin/seq_no/retention_lease_background_sync[p]")),
                             new RuntimeException("failed"));
                     listener.onFailure(e);
-                    if (e instanceof AlreadyClosedException == false && e instanceof IndexShardClosedException == false) {
+                    if (e.getMessage().equals("failed")) {
                         final ArgumentCaptor<ParameterizedMessage> captor = ArgumentCaptor.forClass(ParameterizedMessage.class);
                         verify(retentionLeaseSyncActionLogger).warn(captor.capture(), same(e));
                         final ParameterizedMessage message = captor.getValue();