From bb254f17d1eae9db60f98f3592052e8e7a3091a7 Mon Sep 17 00:00:00 2001
From: Yunze Xu <xyzinfernity@163.com>
Date: Thu, 6 Apr 2023 20:50:33 +0800
Subject: [PATCH] [fix][test] Fix flaky
 testCreateTopicWithZombieReplicatorCursor

Fixes https://github.com/apache/pulsar/issues/20010

### Motivation

`PersistentTopicTest.testCreateTopicWithZombieReplicatorCursor` is flaky
because `onPoliciesUpdate` is asynchronous, while
`testCreateTopicWithZombieReplicatorCursor` updates the namespace policy
nearly the same time, so there is a race with the order of updating
`AbstractTopic#topicPolicies`.

Sometimes the policies update might fail because the topic might be
deleted in `PersistentTopic#checkReplication`:

> Deleting topic [xxx] because local cluster is not part of global namespace repl list [remote]

### Modifications

- Sleep 100ms between two calls of updating the replication clusters
- Add the local cluster to the replication cluster list
- Add the retry logic for `initialize`
---
 .../persistent/PersistentTopicTest.java       | 29 ++++++++++++++-----
 1 file changed, 22 insertions(+), 7 deletions(-)

diff --git a/pulsar-broker/src/test/java/org/apache/pulsar/broker/service/persistent/PersistentTopicTest.java b/pulsar-broker/src/test/java/org/apache/pulsar/broker/service/persistent/PersistentTopicTest.java
index c63be7aad01cd..412b8207e34c7 100644
--- a/pulsar-broker/src/test/java/org/apache/pulsar/broker/service/persistent/PersistentTopicTest.java
+++ b/pulsar-broker/src/test/java/org/apache/pulsar/broker/service/persistent/PersistentTopicTest.java
@@ -38,7 +38,9 @@
 import java.io.ByteArrayOutputStream;
 import java.lang.reflect.Field;
 import java.nio.charset.StandardCharsets;
+import java.time.Duration;
 import java.util.ArrayList;
+import java.util.Arrays;
 import java.util.Collection;
 import java.util.Collections;
 import java.util.HashSet;
@@ -52,6 +54,7 @@
 import java.util.concurrent.atomic.AtomicBoolean;
 import java.util.function.Supplier;
 import lombok.Cleanup;
+import lombok.extern.slf4j.Slf4j;
 import org.apache.bookkeeper.client.LedgerHandle;
 import org.apache.bookkeeper.mledger.ManagedCursor;
 import org.apache.bookkeeper.mledger.ManagedLedger;
@@ -83,6 +86,7 @@
 import org.testng.annotations.DataProvider;
 import org.testng.annotations.Test;
 
+@Slf4j
 @Test(groups = "broker")
 public class PersistentTopicTest extends BrokerTestBase {
 
@@ -558,10 +562,10 @@ public void testCreateTopicWithZombieReplicatorCursor(boolean topicLevelPolicy)
         admin.tenants().updateTenant("prop", tenantInfo);
 
         if (topicLevelPolicy) {
-            admin.topics().setReplicationClusters(topicName, Collections.singletonList(remoteCluster));
+            admin.topics().setReplicationClusters(topicName, Arrays.asList("test", remoteCluster));
         } else {
             admin.namespaces().setNamespaceReplicationClustersAsync(
-                    namespace, Collections.singleton(remoteCluster)).get();
+                    namespace, Sets.newHashSet("test", remoteCluster)).get();
         }
 
         final PersistentTopic topic = (PersistentTopic) pulsar.getBrokerService().getTopic(topicName, false)
@@ -576,16 +580,27 @@ public void testCreateTopicWithZombieReplicatorCursor(boolean topicLevelPolicy)
         };
         assertEquals(getCursors.get(), Collections.singleton(conf.getReplicatorPrefix() + "." + remoteCluster));
 
+        // PersistentTopics#onPoliciesUpdate might happen in different threads, so there might be a race between two
+        // updates of the replication clusters. So here we sleep for a while to reduce the flakiness.
+        Thread.sleep(100);
+
+        // Configure the local cluster to avoid the topic being deleted in PersistentTopics#checkReplication
         if (topicLevelPolicy) {
-            admin.topics().setReplicationClusters(topicName, Collections.emptyList());
+            admin.topics().setReplicationClusters(topicName, Collections.singletonList("test"));
         } else {
-            admin.namespaces().setNamespaceReplicationClustersAsync(namespace, Collections.emptySet()).get();
+            admin.namespaces().setNamespaceReplicationClustersAsync(namespace, Collections.singleton("test")).get();
         }
         admin.clusters().deleteCluster(remoteCluster);
         // Now the cluster and its related policy has been removed but the replicator cursor still exists
 
-        topic.initialize().get(3, TimeUnit.SECONDS);
-        Awaitility.await().atMost(3, TimeUnit.SECONDS)
-                .until(() -> !topic.getManagedLedger().getCursors().iterator().hasNext());
+        Awaitility.await().atMost(Duration.ofSeconds(10)).until(() -> {
+            log.info("Before initialize...");
+            try {
+                topic.initialize().get(3, TimeUnit.SECONDS);
+            } catch (ExecutionException e) {
+                log.warn("Failed to initialize: {}", e.getCause().getMessage());
+            }
+            return !topic.getManagedLedger().getCursors().iterator().hasNext();
+        });
     }
 }