[fix][client] Make auto partitions update work for old brokers without PIP-344 (apache#24822)

(cherry picked from commit 5e59d0e)
(cherry picked from commit 708feff)

Author: BewareMyPower

pulsar-broker/src/test/java/org/apache/pulsar/client/impl/ClientCnxTest.java

@@ -156,7 +156,7 @@ public void testSupportsGetPartitionedMetadataWithoutAutoCreation() throws Excep
             field.set(clientCnxFuture.get(), false);
         }
         try {
-            clientWitBinaryLookup.getPartitionsForTopic(topic, false).join();
+            clientWitBinaryLookup.getPartitionedTopicMetadata(topic, false, false).join();
             Assert.fail("Expected an error that the broker version is too old.");
         } catch (Exception ex) {
             Assert.assertTrue(ex.getMessage().contains("without auto-creation is not supported by the broker"));

pulsar-client/src/main/java/org/apache/pulsar/client/impl/PulsarClientImpl.java

@@ -1212,7 +1212,7 @@ private void getPartitionedTopicMetadata(TopicName topicName,
 
     @Override
     public CompletableFuture<List<String>> getPartitionsForTopic(String topic, boolean metadataAutoCreationEnabled) {
-        return getPartitionedTopicMetadata(topic, metadataAutoCreationEnabled, false).thenApply(metadata -> {
+        return getPartitionedTopicMetadata(topic, metadataAutoCreationEnabled, true).thenApply(metadata -> {
             if (metadata.partitions > 0) {
                 TopicName topicName = TopicName.get(topic);
                 List<String> partitions = new ArrayList<>(metadata.partitions);

tests/integration/src/test/java/org/apache/pulsar/tests/integration/backwardscompatibility/ClientTest2_2.java

@@ -19,8 +19,19 @@
 package org.apache.pulsar.tests.integration.backwardscompatibility;
 
 
+import java.util.List;
+import java.util.concurrent.TimeUnit;
 import java.util.function.Supplier;
+import lombok.Cleanup;
+import org.apache.pulsar.client.admin.PulsarAdmin;
+import org.apache.pulsar.client.api.Message;
+import org.apache.pulsar.client.api.MessageIdAdv;
+import org.apache.pulsar.client.api.MessageRouter;
+import org.apache.pulsar.client.api.MessageRoutingMode;
+import org.apache.pulsar.client.api.PulsarClient;
+import org.apache.pulsar.client.api.TopicMetadata;
 import org.apache.pulsar.tests.integration.topologies.ClientTestBase;
+import org.testng.Assert;
 import org.testng.annotations.Test;
 
 public class ClientTest2_2 extends PulsarStandaloneTestSuite2_2 {
@@ -33,4 +44,47 @@ public void testResetCursorCompatibility(Supplier<String> serviceUrl, Supplier<S
         clientTestBase.resetCursorCompatibility(serviceUrl.get(), httpServiceUrl.get(), topicName);
     }
 
+    @Test(timeOut = 20000)
+    public void testAutoPartitionsUpdate() throws Exception {
+        @Cleanup final var pulsarClient = PulsarClient.builder()
+                .serviceUrl(getContainer().getPlainTextServiceUrl())
+                .build();
+        final var topic = "test-auto-part-update";
+        final var topic2 = "dummy-topic";
+        @Cleanup final var admin = PulsarAdmin.builder().serviceHttpUrl(getContainer().getHttpServiceUrl()).build();
+        // Use 2 as the initial partition number because old version broker cannot update partitions on a topic that
+        // has only 1 partition.
+        admin.topics().createPartitionedTopic(topic, 2);
+        admin.topics().createPartitionedTopic(topic2, 2);
+        @Cleanup final var producer = pulsarClient.newProducer().autoUpdatePartitions(true)
+                .autoUpdatePartitionsInterval(1, TimeUnit.SECONDS)
+                .messageRoutingMode(MessageRoutingMode.CustomPartition)
+                .messageRouter(new MessageRouter() {
+                    @Override
+                    public int choosePartition(Message<?> msg, TopicMetadata metadata) {
+                        return metadata.numPartitions() - 1;
+                    }
+                })
+                .topic(topic)
+                .create();
+        @Cleanup final var consumer = pulsarClient.newConsumer().autoUpdatePartitions(true)
+                .autoUpdatePartitionsInterval(1, TimeUnit.SECONDS)
+                .topic(topic).subscriptionName("sub")
+                .subscribe();
+        @Cleanup final var multiTopicsConsumer = pulsarClient.newConsumer().autoUpdatePartitions(true)
+                .autoUpdatePartitionsInterval(1, TimeUnit.SECONDS)
+                .topics(List.of(topic, topic2)).subscriptionName("sub-2").subscribe();
+
+        admin.topics().updatePartitionedTopic(topic, 3);
+        Thread.sleep(1500);
+        final var msgId = (MessageIdAdv) producer.send("msg".getBytes());
+        Assert.assertEquals(msgId.getPartitionIndex(), 2);
+
+        final var msg = consumer.receive(3, TimeUnit.SECONDS);
+        Assert.assertNotNull(msg);
+        Assert.assertEquals(((MessageIdAdv) msg.getMessageId()).getPartitionIndex(), 2);
+        final var msg2 = multiTopicsConsumer.receive(3, TimeUnit.SECONDS);
+        Assert.assertNotNull(msg2);
+        Assert.assertEquals(msg2.getMessageId(), msg.getMessageId());
+    }
 }