Safely stop(close replication-producer) and remove replicator (#152)

pulsar-broker/src/main/java/com/yahoo/pulsar/broker/service/persistent/PersistentReplicator.java

@@ -605,7 +605,8 @@ public synchronized CompletableFuture<Void> disconnect(boolean failIfHasBacklog)
             return disconnectFuture;
         }
 
-        if (producer != null && state.compareAndSet(State.Started, State.Stopping)) {
+        if (producer != null && (state.compareAndSet(State.Starting, State.Stopping)
+                || state.compareAndSet(State.Started, State.Stopping))) {
             log.info("[{}][{} -> {}] Disconnect replicator at position {} with backlog {}", topicName, localCluster,
                     remoteCluster, cursor.getMarkDeletedPosition(), cursor.getNumberOfEntriesInBacklog());
             return closeProducerAsync();

pulsar-broker/src/main/java/com/yahoo/pulsar/broker/service/persistent/PersistentTopic.java

@@ -119,6 +119,8 @@ public class PersistentTopic implements Topic, AddEntryCallback {
     public final String replicatorPrefix;
 
     private static final double MESSAGE_EXPIRY_THRESHOLD = 1.5;
+
+    private static final long POLICY_UPDATE_FAILURE_RETRY_TIME_SECONDS = 60;
 
     public static final DateTimeFormatter DATE_FORMAT = DateTimeFormatter.ofPattern("yyyy-MM-dd HH:mm:ss.SSS").withZone(ZoneId.systemDefault());
 
@@ -544,6 +546,22 @@ public void closeFailed(ManagedLedgerException exception, Object ctx) {
         return closeFuture;
     }
 
+    private CompletableFuture<Void> checkReplicationAndRetryOnFailure() {
+        CompletableFuture<Void> result = new CompletableFuture<Void>();
+        checkReplication().thenAccept(res -> {
+            log.info("[{}] Policies updated successfully", topic);
+            result.complete(null);
+        }).exceptionally(th -> {
+            log.error("[{}] Policies update failed {}, scheduled retry in {} seconds", topic, th.getMessage(),
+                    POLICY_UPDATE_FAILURE_RETRY_TIME_SECONDS, th);
+            brokerService.executor().schedule(this::checkReplicationAndRetryOnFailure,
+                    POLICY_UPDATE_FAILURE_RETRY_TIME_SECONDS, TimeUnit.SECONDS);
+            result.completeExceptionally(th);
+            return null;
+        });
+        return result;
+    }
+
     @Override
     public CompletableFuture<Void> checkReplication() {
         DestinationName name = DestinationName.get(topic);
@@ -665,15 +683,13 @@ public void deleteCursorComplete(Object ctx) {
 
                 @Override
                 public void deleteCursorFailed(ManagedLedgerException exception, Object ctx) {
-                    log.error("[{}] Failed to delete cursor {}", topic, name);
-                    // Connect the producers back
-                    replicators.get(remoteCluster).startProducer();
+                    log.error("[{}] Failed to delete cursor {} {}", topic, name, exception.getMessage(), exception);
                     future.completeExceptionally(new PersistenceException(exception));
                 }
             }, null);
 
         }).exceptionally(e -> {
-            log.error("[{}] Failed to close replication producer {}", topic, name);
+            log.error("[{}] Failed to close replication producer {} {}", topic, name, e.getMessage(), e);
             future.completeExceptionally(e);
             return null;
         });
@@ -1082,7 +1098,7 @@ public CompletableFuture<Void> onPoliciesUpdate(Policies data) {
         producers.forEach(Producer::checkPermissions);
         subscriptions.forEach((subName, sub) -> sub.getConsumers().forEach(Consumer::checkPermissions));
         checkMessageExpiry();
-        return checkReplication();
+        return checkReplicationAndRetryOnFailure();
     }
 
     /**

pulsar-broker/src/test/java/com/yahoo/pulsar/broker/service/ReplicatorTest.java

@@ -29,12 +29,15 @@
 import java.util.concurrent.CompletableFuture;
 import java.util.concurrent.ExecutorService;
 import java.util.concurrent.Executors;
+import java.util.concurrent.CountDownLatch;
 import java.util.concurrent.Future;
 import java.util.concurrent.TimeUnit;
 
+import org.apache.bookkeeper.mledger.AsyncCallbacks.DeleteCursorCallback;
 import org.apache.bookkeeper.mledger.Entry;
 import org.apache.bookkeeper.mledger.ManagedLedgerException;
 import org.mockito.Mockito;
+import org.apache.bookkeeper.mledger.impl.ManagedLedgerImpl;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 import org.testng.Assert;
@@ -54,6 +57,7 @@
 import com.yahoo.pulsar.client.api.Producer;
 import com.yahoo.pulsar.client.api.PulsarClient;
 import com.yahoo.pulsar.client.impl.PulsarClientImpl;
+import com.yahoo.pulsar.client.impl.ProducerImpl;
 import com.yahoo.pulsar.common.naming.DestinationName;
 import com.yahoo.pulsar.common.naming.NamespaceBundle;
 import com.yahoo.pulsar.common.naming.NamespaceName;
@@ -604,6 +608,68 @@ public Void call() throws Exception {
             }
         }
     }
+
+    /**
+     * It verifies that: if it fails while removing replicator-cluster-cursor: it should not restart the replicator and
+     * it should have cleaned up from the list
+     * 
+     * @throws Exception
+     */
+    @Test
+    public void testDeleteReplicatorFailure() throws Exception {
+        log.info("--- Starting ReplicatorTest::testDeleteReplicatorFailure ---");
+        final String topicName = "persistent://pulsar/global/ns/repltopicbatch";
+        final DestinationName dest = DestinationName.get(topicName);
+        MessageProducer producer1 = new MessageProducer(url1, dest);
+        PersistentTopic topic = (PersistentTopic) pulsar1.getBrokerService().getTopicReference(topicName);
+        final String replicatorClusterName = topic.getReplicators().keys().get(0);
+        ManagedLedgerImpl ledger = (ManagedLedgerImpl) topic.getManagedLedger();
+        CountDownLatch latch = new CountDownLatch(1);
+        // delete cursor already : so next time if topic.removeReplicator will get exception but then it should
+        // remove-replicator from the list even with failure
+        ledger.asyncDeleteCursor("pulsar.repl." + replicatorClusterName, new DeleteCursorCallback() {
+            @Override
+            public void deleteCursorComplete(Object ctx) {
+                latch.countDown();
+            }
+
+            @Override
+            public void deleteCursorFailed(ManagedLedgerException exception, Object ctx) {
+                latch.countDown();
+            }
+        }, null);
+        latch.await();
+
+        Method removeReplicator = PersistentTopic.class.getDeclaredMethod("removeReplicator", String.class);
+        removeReplicator.setAccessible(true);
+        // invoke removeReplicator : it fails as cursor is not present: but still it should remove the replicator from
+        // list without restarting it
+        CompletableFuture<Void> result = (CompletableFuture<Void>) removeReplicator.invoke(topic,
+                replicatorClusterName);
+        result.thenApply((v) -> {
+            assertNull(topic.getPersistentReplicator(replicatorClusterName));
+            return null;
+        });
+    }
+
+    @Test
+    public void testReplicatorProducerClosing() throws Exception {
+        log.info("--- Starting ReplicatorTest::testDeleteReplicatorFailure ---");
+        final String topicName = "persistent://pulsar/global/ns/repltopicbatch";
+        final DestinationName dest = DestinationName.get(topicName);
+        MessageProducer producer1 = new MessageProducer(url1, dest);
+        PersistentTopic topic = (PersistentTopic) pulsar1.getBrokerService().getTopicReference(topicName);
+        final String replicatorClusterName = topic.getReplicators().keys().get(0);
+        PersistentReplicator replicator = topic.getPersistentReplicator(replicatorClusterName);
+        pulsar2.close();
+        pulsar3.close();
+        replicator.disconnect(false);
+        Thread.sleep(100);
+        Field field = PersistentReplicator.class.getDeclaredField("producer");
+        field.setAccessible(true);
+        ProducerImpl producer = (ProducerImpl) field.get(replicator);
+        assertNull(producer);
+    }
 
     private static final Logger log = LoggerFactory.getLogger(ReplicatorTest.class);
 

pulsar-common/src/main/java/com/yahoo/pulsar/common/policies/data/Policies.java

@@ -73,4 +73,15 @@ public static BundlesData defaultBundle() {
         bundle.setBoundaries(boundaries);
         return bundle;
     }
+
+    @Override
+    public String toString() {
+        return Objects.toStringHelper(this).add("auth_policies", auth_policies)
+                .add("replication_clusters", replication_clusters).add("bundles", bundles)
+                .add("backlog_quota_map", backlog_quota_map).add("persistence", persistence)
+                .add("latency_stats_sample_rate", latency_stats_sample_rate)
+                .add("message_ttl_in_seconds", message_ttl_in_seconds).add("retention_policies", retention_policies)
+                .add("deleted", deleted).toString();
+    }
+
 }