[fix][test] NamespaceServiceTest.testSplitBundleWithHighestThroughput

[Demogorgon314]

Fixes #16705

Motivation

When the getBundleWithHighestThroughput method try to use ((ModularLoadManagerWrapper)loadManager).getLoadManager().getBundleDataOrDefault(bundle.toString()); get the bundle load data, the load data might already updated by load manager.

pulsar/pulsar-broker/src/main/java/org/apache/pulsar/broker/loadbalance/impl/ModularLoadManagerImpl.java

Lines 1109 to 1119 in 4483df2

	public void writeBundleDataOnZooKeeper() {
	updateBundleData();
	// Write the bundle data to metadata store.
	List<CompletableFuture<Void>> futures = new ArrayList<>();
	for (Map.Entry<String, BundleData> entry : loadData.getBundleData().entrySet()) {
	final String bundle = entry.getKey();
	final BundleData data = entry.getValue();
	futures.add(bundlesCache.readModifyUpdateOrCreate(getBundleDataPath(bundle), __ -> data)
	.thenApply(__ -> null));
	}

Also, we should give the bundleWithHighestThroughput a default value, since is possible to return a null value.

Modifications

• Disable the writeResourceQuotasToZooKeeper task by set load balancer enabled false.

Documentation

Check the box below or label this PR directly.

Need to update docs?

• doc-required
  (Your PR needs to update docs and you will update later)

• doc-not-needed
  (Please explain why)

• doc
  (Your PR contains doc changes)

• doc-complete
  (Docs have been already added)

[codelipenghui]

Hmmm, it's a little confusing. The test is related to the load manager but need to disable the load balancer in the test.

[codelipenghui]

I think without this change, the flaky test can also be fixed? Since we will not return null for method getBundleWithHighestThroughput

[Demogorgon314]

No, disable the load balancer just to cancel the load report task.

You can see the below code, in this test, it tries to write the mock load data to storage, but if the load report task starts, the mock data might be overridden.

pulsar/pulsar-broker/src/test/java/org/apache/pulsar/broker/namespace/NamespaceServiceTest.java

Lines 625 to 634 in 0134908

	NamespaceBundle targetNamespaceBundle = bundles.findBundle(TopicName.get(topic + "0"));
	String bundle = targetNamespaceBundle.getBundleRange();
	String path = ModularLoadManagerImpl.getBundleDataPath(namespace + "/" + bundle);
	NamespaceBundleStats defaultStats = new NamespaceBundleStats();
	defaultStats.msgThroughputIn = 100000;
	defaultStats.msgThroughputOut = 100000;
	BundleData bd = new BundleData(10, 19, defaultStats);
	bd.setTopics(10);
	byte[] data = ObjectMapperFactory.getThreadLocal().writeValueAsBytes(bd);
	pulsar.getLocalMetadataStore().put(path, data, Optional.empty());

[shibd]

I don't understand, I think even if the bundle is updated, we should always be able to find the one with the highest load?

[Demogorgon314]

If the bundle don't have any connected topic, the check bundleData.getTopics() > 0 will never pass, so the bundleWithHighestThroughput is null.

[Technoboy-]

We need to discuss more about this modification, because it seems change back to #12957.

[github-actions]

The pr had no activity for 30 days, mark with Stale label.

[congbobo184]

@Demogorgon314 hi, I move this PR to release/2.9.5, if you have any questions, please ping me. thanks.