I think I'm finally in the position to push ZK into production for a while
to test it out.
My biggest feedback (other than the small bugs I found) was that the API
could be a bit simpler.
I codified my thoughts here:
Basically, I was thinking that one could receive an onData event to receive
the initial value.
Then all future events would call onData.....
I was thinking that an onExists() method might also be nice.
The current API could be made cleaner with:
- one or two standalone Listener interfaces with onFoo methods for each
- the processResults() method is the same for each interface right now
which is somewhat confusing. Using onFoo is more self documenting.
- using the main thread by using poll() to wait for events from ZooKeeper.
I use a ConcurrentLinkedQueue in my implementation.
Also, is there a race condition between when the client receives an event
for an update and before it can request a new one? I was thinking session
local based events would solve this problem (you register your watch once
per session and then get all events until it is unregistered).
I think this can be solved in my code by reading the current version of the
value from the getData() method I call when I register the new watch and
comparing it to the last version I saw. If it was incremented then I would
call onData again.
The problem here is that I might miss two updates (but at least I would
receive the last stable value).
Location: San Francisco, CA