Hi Folks,
I've written a proof of concept implementation of a ServerCnxnFactory that
implements gRPC. The goal is to make it possible to easily write ZooKeeper
clients in non-JVM languages. Using the proof of concept I was able to write a
Golang client easily. What's the interest level of something like this? Let's
discuss if it's worth pursuing. I'd be willing to move this from proof of
concept to production but I'll need help (1 or 2 co-developers).
If you want to try it, I've pushed the Golang client and some instructions here
(let me know if you have any issues - I'm a go neophyte). Note:
"zookeeper/test.go" is the interesting file:
https://github.com/Randgalt/zkgrpc <https://github.com/Randgalt/zkgrpc>
Here's the proof of concept on the ZK server side (the interesting files are
RpcServerCnxn.java, RpcServerCnxnFactory.java, RpcZooKeeperServer.java and
zookeeper.proto):
https://github.com/apache/zookeeper/compare/master...Randgalt:wip-grpc
<https://github.com/apache/zookeeper/compare/master...Randgalt:wip-grpc>
Issues:
Writing a client, even with gRPC, will require some work. Sessions have to be
maintained, watchers have to be maintained, etc.
Currently, Jute is deeply embedded in ZooKeeper. The proof of concept has to
emulate Jute byte buffers. Ideally, this will be abstracted so that only
records could be used so that the gRPC connection doesn't have to keep
marshalling/unmarshalling byte buffers
I don't know enough about the gRPC client/server implementations to know if it
will meet the needs of ZooKeeper. Anyone have experience here?
I haven't completely thought through how much work it will take to write useful
clients. As I've shown with the proof of concept simple ZK CRUD db operations
work well. I need to spend time writing a recipe such as Leader Election to see
how much work is required.
I'm not sure how things like SASL and reconfig would work with gRPC
-Jordan
