Suppress lease background sync failures if stopping (elastic#40902)

If the transport service is stopped, likely because we are shutting
down, and a retention lease background sync fires the logs will display
a warn message and stacktrace. Yet, this situaton is harmless and can
happen as a normal course of business when shutting down. This commit
suppresses the log messages in this case.

server/src/main/java/org/elasticsearch/ExceptionsHelper.java

@@ -29,6 +29,7 @@
 import org.elasticsearch.common.util.concurrent.EsRejectedExecutionException;
 import org.elasticsearch.index.Index;
 import org.elasticsearch.rest.RestStatus;
+import org.elasticsearch.transport.TransportException;
 
 import java.io.IOException;
 import java.io.PrintWriter;
@@ -193,6 +194,14 @@ public static Throwable unwrap(Throwable t, Class<?>... clazzes) {
         return null;
     }
 
+    public static boolean isTransportStoppedForAction(final Throwable t, final String action) {
+        final TransportException maybeTransport =
+                (TransportException) ExceptionsHelper.unwrap(t, TransportException.class);
+        return maybeTransport != null
+                && (maybeTransport.getMessage().equals("TransportService is closed stopped can't send request")
+                || maybeTransport.getMessage().equals("transport stopped, action: " + action));
+    }
+
     /**
      * Throws the specified exception. If null if specified then <code>true</code> is returned.
      */

server/src/main/java/org/elasticsearch/action/support/replication/ReplicationOperation.java

@@ -38,7 +38,6 @@
 import org.elasticsearch.index.shard.ShardId;
 import org.elasticsearch.node.NodeClosedException;
 import org.elasticsearch.rest.RestStatus;
-import org.elasticsearch.transport.TransportException;
 
 import java.io.IOException;
 import java.util.ArrayList;
@@ -205,10 +204,9 @@ public String toString() {
 
     private void onNoLongerPrimary(Exception failure) {
         final Throwable cause = ExceptionsHelper.unwrapCause(failure);
-        final boolean nodeIsClosing = cause instanceof NodeClosedException
-            || (cause instanceof TransportException &&
-                ("TransportService is closed stopped can't send request".equals(cause.getMessage())
-                || "transport stopped, action: internal:cluster/shard/failure".equals(cause.getMessage())));
+        final boolean nodeIsClosing =
+                cause instanceof NodeClosedException
+                        || ExceptionsHelper.isTransportStoppedForAction(cause, "internal:cluster/shard/failure");
         final String message;
         if (nodeIsClosing) {
             message = String.format(Locale.ROOT,

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

@@ -113,9 +113,15 @@ 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);
+                                if (ExceptionsHelper.isTransportStoppedForAction(e, 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

@@ -274,6 +274,7 @@ public void onFailure(Exception e) {
                     }
                     @Override
                     public void doRun() {
+                        // cf. ExceptionsHelper#isTransportStoppedForAction
                         TransportException ex = new TransportException("transport stopped, action: " + holderToNotify.action());
                         holderToNotify.handler().handleException(ex);
                     }
@@ -626,8 +627,13 @@ 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? cf. ExceptionsHelper#isTransportStoppedForAction
                 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();