Flaky-test: org.apache.distributedlog.TestBKDistributedLogManager testTwoWritersOnLockDisabled flakes with "KeeperErrorCode = BadVersion"

[dlg99]

happens on attempt to create second writer immediately after the first one. i only was able to repro this by running the whole suite, rtest passses if I run just this test alone. Sleep between writer creations helps with the test but probably this worth looking at.

        AsyncLogWriter writer1 = Utils.ioResult(manager.openAsyncLogWriter());
        Utils.ioResult(writer1.write(DLMTestUtil.getLogRecordInstance(1L)));
        Assert.assertEquals(1L, writer1.getLastTxId());
        // some flaky ZK errors after that
        //Thread.sleep(1000);
        AsyncLogWriter writer2 = Utils.ioResult(manager.openAsyncLogWriter());

13:48:06.116 [Time-limited test-EventThread] ERROR org.apache.distributedlog.bk.SimpleLedgerAllocator - Fail mark ledger 98 as allocated under /messaging/distributedlog/distrlog-two-writers-lock-disabled/distrlog-two-writers-lock-disabled/<default>/allocation : 
org.apache.zookeeper.KeeperException$BadVersionException: KeeperErrorCode = BadVersion
	at org.apache.zookeeper.KeeperException.create(KeeperException.java:122) ~[zookeeper-3.6.2.jar:3.6.2]
	at org.apache.distributedlog.util.Utils$5.processResult(Utils.java:395) [main/:?]
	at org.apache.bookkeeper.zookeeper.ZooKeeperClient$22$1.processResult(ZooKeeperClient.java:1094) [bookkeeper-server.jar:?]
	at org.apache.zookeeper.ClientCnxn$EventThread.processEvent(ClientCnxn.java:637) [zookeeper-3.6.2.jar:3.6.2]
	at org.apache.zookeeper.ClientCnxn$EventThread.run(ClientCnxn.java:562) [zookeeper-3.6.2.jar:3.6.2]

Encountered zookeeper exception on waiting result
org.apache.distributedlog.exceptions.ZKException: Encountered zookeeper exception on waiting result
	at app//org.apache.distributedlog.util.Utils.lambda$ioResult$0(Utils.java:693)
	at app//org.apache.bookkeeper.common.concurrent.FutureUtils.result(FutureUtils.java:77)
	at app//org.apache.distributedlog.util.Utils.ioResult(Utils.java:687)
	at app//org.apache.distributedlog.TestBKDistributedLogManager.testTwoWritersOnLockDisabled(TestBKDistributedLogManager.java:365)
	at [email protected]/jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
	at [email protected]/jdk.internal.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
	at [email protected]/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
	at [email protected]/java.lang.reflect.Method.invoke(Method.java:566)
	at app//org.junit.runners.model.FrameworkMethod$1.runReflectiveCall(FrameworkMethod.java:50)
	at app//org.junit.internal.runners.model.ReflectiveCallable.run(ReflectiveCallable.java:12)
	at app//org.junit.runners.model.FrameworkMethod.invokeExplosively(FrameworkMethod.java:47)
	at app//org.junit.internal.runners.statements.InvokeMethod.evaluate(InvokeMethod.java:17)
	at app//org.junit.internal.runners.statements.FailOnTimeout$CallableStatement.call(FailOnTimeout.java:298)
	at app//org.junit.internal.runners.statements.FailOnTimeout$CallableStatement.call(FailOnTimeout.java:292)
	at [email protected]/java.util.concurrent.FutureTask.run(FutureTask.java:264)
	at [email protected]/java.lang.Thread.run(Thread.java:829)
Caused by: org.apache.zookeeper.KeeperException$BadVersionException: KeeperErrorCode = BadVersion
	at app//org.apache.zookeeper.KeeperException.create(KeeperException.java:122)
	at app//org.apache.distributedlog.util.Utils$5.processResult(Utils.java:395)
	at app//org.apache.bookkeeper.zookeeper.ZooKeeperClient$22$1.processResult(ZooKeeperClient.java:1094)
	at app//org.apache.zookeeper.ClientCnxn$EventThread.processEvent(ClientCnxn.java:637)
	at app//org.apache.zookeeper.ClientCnxn$EventThread.run(ClientCnxn.java:562)