[CURATOR-355] Curator client fails when connecting to read-only ensemble

• Type: Bug
• Status: Open
• Priority: Critical
• Resolution: Unresolved
• Affects Version/s: 2.11.0
• Component/s: Client
• Assignee: Unassigned
• Reporter: Benjamin Jaton
• Created: 10/Oct/16 17:09
• Updated: 28/Mar/19 22:17

Description

ZK is 3.5.1-alpha

I have a 3 nodes ZK cluster , readonly mode is enabled.
2 nodes are down, so one of them (QA-E8WIN11) is in read-only (verified by using the ZK API manually). All the machines of the ensemble can be pinged from the client.

I'm using this piece of code:

		Builder curatorClientBuilder = CuratorFrameworkFactory.builder()
				.connectString("QA-E8WIN11:2181,QA-E8WIN12:2181")
				.sessionTimeoutMs(45000).connectionTimeoutMs(15000)
				.retryPolicy(new RetryNTimes(3, 5000)).canBeReadOnly(true);

		CuratorFramework client = curatorClientBuilder.build();
		client.start();
		client.getZookeeperClient().blockUntilConnectedOrTimedOut();
		System.out.println("Successfully established the connection with ZooKeeper");
		
		client.getData().forPath("/");
		System.out.println("Done.");

When curator pick the host that is UP first, it goes through very quickly. When it picks the host that is down first (QA-E8WIN12), it seems to be stuck at the getData() call for a very long time, and then eventually fail with a ConnectionLossException. (see attached log)