[CURATOR-365] backgroundCreateParentsThenNode() ignores exceptions too crudely

• Type: Bug
• Status: Resolved
• Priority: Critical
• Resolution: Fixed
• Affects Version/s: 3.2.0, 2.11.1
• Fix Version/s: 3.3.0, 2.12.0
• Component/s: Framework
• Assignee: Jordan Zimmerman
• Reporter: Jordan Zimmerman
• Created: 16/Dec/16 22:26
• Updated: 19/Dec/16 20:03
• Resolved: 19/Dec/16 20:03

Description

backgroundCreateParentsThenNode() in CreateBuilderImpl,java is ignoring all KeeperExceptions. This can cause an infinite loop if the KeeperException is not an ignorable one.

Here's a code snippet that shows the problem:

@Test
public void testIt() throws Exception
{
    ACLProvider provider = new ACLProvider()
    {
        @Override
        public List<ACL> getDefaultAcl()
        {
            return ZooDefs.Ids.OPEN_ACL_UNSAFE;
        }

        @Override
        public List<ACL> getAclForPath(String path)
        {
            if ( path.equals("/ns/one") )
            {
                try
                {
                    return Collections.singletonList(new ACL(ZooDefs.Perms.ALL, new Id("digest", DigestAuthenticationProvider.generateDigest("test"))));
                }
                catch ( NoSuchAlgorithmException e )
                {
                    e.printStackTrace();
                }
            }
            return getDefaultAcl();
        }
    };
    try ( CuratorFramework client = createClient(provider, new AuthInfo("digest", DigestAuthenticationProvider.generateDigest("test").getBytes())) )
    {
        LeaderLatch latch = new LeaderLatch(client, "/one/two");
        latch.start();
        latch.await();
        System.err.println("hdeherherhe");
    }
}

private CuratorFramework createClient(ACLProvider provider, AuthInfo authInfo) throws Exception
{
    RetryPolicy retryPolicy = new ExponentialBackoffRetry(1000, 3);
    CuratorFrameworkFactory.Builder builder = CuratorFrameworkFactory.builder()
        .namespace("ns")
        .connectString(server.getConnectString())
        .retryPolicy(retryPolicy)
        ;
    if ( provider != null )
    {
        builder = builder.aclProvider(provider);
    }
    if ( authInfo != null )
    {
        builder = builder.authorization(authInfo.getScheme(), authInfo.getAuth());
    }
    CuratorFramework client = builder.build();
    client.start();
    return client;
}

While this is running you can put a breakpoint on CreateBuilderImpl#findProtectedNodeInForeground() and see it get called over and over.

Issue Links

• links to: GitHub Pull Request #178