CURATOR-526 drop log level for message to debug

[akhaku]

ZooKeeper is backwards compatible and accepts older config
string formats, albeit without dynamic configuration
support. Since the older format is acceptable, we should not
log at error when we see the older format and should
instead simply log at debug.

[akhaku]

I'd love to get this into 4.x as well as the current 5.x branch, appreciate guidance on how to make that happen!

[eolivelli]

the problem is the noise of the error level ?

if the problem is the log level, then we can use "info"

[akhaku]

It is indeed the noise. I picked debug over info because the log message at 219 below is for a similar case (missing config) and is at debug, but happy to change it to info instead, thoughts?

[eolivelli]

Can you paste a sample line of the log you are seeing?

[akhaku]

Here's an example:

Invalid config event received: {server.1=100.1.2.3:2888:3888:participant, version=0, server.5=100.2.3.4:2888:3888:participant, server.4=100.3.4.5:2888:3888:participant, server.3=100.4.5.6:2888:3888:participant, server.2=100.5.6.7:2888:3888:participant}

There's a bit more discussion on the Jira ticket, in case you haven't seen that yet.

[leandrodalbo]

        StringBuilder sb = new StringBuilder();
        Iterator var2 = data.getAllMembers().values().iterator();

        while(var2.hasNext()) {
            QuorumServer server = (QuorumServer)var2.next();
            if (server.clientAddr != null) {
                if (sb.length() != 0) {
                    sb.append(",");
                }

                String hostAddress;
                if (server.clientAddr.getAddress().isAnyLocalAddress()) {
                    hostAddress = Compatibility.getHostAddress(server);
                } else {
                    hostAddress = server.clientAddr.getAddress().getHostAddress();
                }

                sb.append(hostAddress).append(":").append(server.clientAddr.getPort());
            }
        }

        return sb.toString();
    }```

- I think it is processing the **version=0** like another server more when it shouldn't. 
- Do we know if this is affecting any functionality or not?

[Helmsdown]

+1 to this change.

[eolivelli]

LGTM

[eolivelli]

Committer to master branch.
thanks