mattisonchao commented on code in PR #17700:
URL: https://github.com/apache/pulsar/pull/17700#discussion_r973835719
##########
pulsar-metadata/src/test/java/org/apache/pulsar/metadata/LockManagerTest.java:
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@@ -293,4 +296,55 @@ public void revalidateLockOnDifferentSession(String
provider, Supplier<String> u
assertEquals(new
String(store1.get(path2).join().get().getValue()), "\"value-1\"");
});
}
+
+ @Test(dataProvider = "impl")
+ public void testCleanUpStateWhenRevalidationGotLockBusy(String provider,
Supplier<String> urlSupplier)
+ throws Exception {
+
+ if (provider.equals("Memory") || provider.equals("RocksDB")) {
+ // Local memory provider doesn't really have the concept of
multiple sessions
+ return;
+ }
+
+ @Cleanup
+ MetadataStoreExtended store1 =
MetadataStoreExtended.create(urlSupplier.get(),
+ MetadataStoreConfig.builder().build());
+ @Cleanup
+ MetadataStoreExtended store2 =
MetadataStoreExtended.create(urlSupplier.get(),
+ MetadataStoreConfig.builder().build());
+
+ @Cleanup
+ CoordinationService cs1 = new CoordinationServiceImpl(store1);
+ @Cleanup
+ LockManager<String> lm1 = cs1.getLockManager(String.class);
+
+ @Cleanup
+ CoordinationService cs2 = new CoordinationServiceImpl(store2);
+ @Cleanup
+ LockManager<String> lm2 = cs2.getLockManager(String.class);
+
+ String path1 = newKey();
+
+ ResourceLock<String> lock1 = lm1.acquireLock(path1, "value-1").join();
+ AtomicReference<ResourceLock<String>> lock2 = new AtomicReference<>();
+ // lock 2 will steal the distributed lock first.
Review Comment:
When I am writing this test, I found an interesting thing. We can allow the
new lock to steal the existing lock that may hold by others(same value).
I'm not sure if it's a big problem. You can use this test to verify this
behaviour.
Plus, steal lock behaviour may cause an infinity loop when they use the same
value or a different value in the same session. the details please see
`ResourceLockImpl#doRevalidate`
https://github.com/apache/pulsar/blob/69f3f7471fa6faf24d4776d65e0509538c105d37/pulsar-metadata/src/main/java/org/apache/pulsar/metadata/coordination/impl/ResourceLockImpl.java#L239-L310
Case:
- lock 1 holds the lock with value `value-1`.
- lock 2 tries to acquire the lock with value `value-1` got the
`LockBusyException` then invoked `revalidate` to steal the lock. (delete and
re-create it)
- lock 1 receives the delete notification **after lock 2 already acquires
the lock**. then lock1 tries to invoke `revalidate` to steal the lock again.
- Under this assumption, we're going to fall into an infinite loop.
This is a theoretical assumption because the situation is more difficult to
simulate. Please take a look, I'm not sure if I missing something.
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