On Tue, Nov 29, 2016, at 11:39, Ashish Singh wrote: > Hello Colin, > > In the KIP you mentioned that currently the client uses supported api > versions information to check if the server supports its desired > versions. > Not sure, if that is true. I had put together a PR for KAFKA-3600, to do > that, but it never went in.
I was taking a look at the RPC implementation today myself and I think you're right. I don't think the client actually invokes ApiVersionRequest-- or if it does, I can't find the invocation site. Still, the API versions are sent over the wire, and the server does use them to support older clients. I suppose this means that currently, clients which are too new fail at the time they attempt to send an RPC which is not in the server's supported version range for that RPC. I will edit the KIP to reflect this-- thanks. > Also, I could not find how you plan to perform > version check on client side. In KAFKA-3600, I am maintaining api version > for each live connection, and that made a few folks think it is too big > of a change. The version check would be performed by calling ApiVersionRequest, just like in your patch. I think that people are coming around to the idea that we need both forward and backwards compatibility for the client. As the project grows, and there are bigger and more deployments, it is probably worth spending a little more time on compatibility... P.S. If you have any spare cycles, it would be great to collaborate on this! cheers, Colin > > On Tue, Nov 29, 2016 at 11:05 AM, Colin McCabe <cmcc...@apache.org> > wrote: > > > Sorry, that link should be: > > https://cwiki.apache.org/confluence/display/KAFKA/KIP- > > 97%3A+Improved+Kafka+Client+RPC+Compatibility+Policy > > > > > > > > On Tue, Nov 29, 2016, at 11:04, Colin McCabe wrote: > > > Hi all, > > > > > > I've been thinking about a KIP to improve the Kafka client's > > > compatibility policy. If you're interested, please check out: > > > https://cwiki.apache.org/confluence/display/KAFKA/KIP- > > 97%3A+Improved+Kafka+Compatibility+Policy > > > > > > cheers, > > > Colin > > > > > > -- > > Regards, > Ashish
