Upgrade Apache Curator framework to 4.0.x - SSL Support

[gardnervickers]

Some users are running hosted Zookeeper, requiring a SSL connection. Curator framework 4 on supports this by using the ZK client libs 3.5.1.

[lbradstreet]

Ugh, the problem with this is that curator 4.0 only supports ZK 3.5+. Maybe we will have to have an exclusions section in our doc?

[Thingographist]

@lbradstreet i tried using CF v4.0 in my project for watching changes in ZK
And it work with ZK versions 3.4 and 3.5. However i generally use only ZK 3.4.
Dependent project have not problems.

But CF v4.0 allow TTL marks for nodes and it's awesome feature for persistent state of cluster and data flow.

[lbradstreet]

Thanks for the report @Thingographist. I tried bumping curator to v4.0, but it was not compatible with ZK 3.4.11 running via docker (threw some compatibility errors). Did you test it against an external ZK? I would love to upgrade it, but unless it's compatible with 3.4 it will be hard.

[Thingographist]

For development i run cluster on dockerised ZK v3.4.11.
For staging - ZK v3.4.5 on root OS (from official debian repository).
And it's work with CF 4.0.

Just simple fix from official docs:

[[org.apache.curator/curator-framework "4.0.0"]
 [org.apache.curator/curator-recipes "4.0.0"]
 [org.apache.curator/curator-test "4.0.0"]]
 [org.apache.zookeeper/zookeeper "3.4.11"]
 [org.apache.curator/curator-client "4.0.0" :exclusions [org.apache.zookeeper/zookeeper]
 [org.onyxplatform/onyx "0.12.7-1519160025" :exclusions [
          org.apache.curator/curator-framework
          org.apache.curator/curator-test
          org.apache.zookeeper/zookeeper]]]

And it's work without using isZk34CompatibilityMode method.

This fixes disable features of v3.5, but some methods from CF is works (for example: Tree Cache, Persistent TTL Node).
And isZk34CompatibilityMode method maybe globally enable/disable 3.5 features.

[lbradstreet]

Awesome! isZk34CompatibilityMode is the key insight that I was missing :). I'll give this a go tonight.

[lbradstreet]

Upgraded in master and 0.13.0 (soon to be released). Closing