On Tue, Nov 29, 2016 at 4:11 PM, Colin McCabe <co...@cmccabe.xyz> wrote:
> 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! > Kafka-3600 was part of voted-in KIP-35, and a pre-requisite for client compat. If people are coming around to the idea, maybe we can revisit KAFKA-3600 and try to find why is it not meaningful to have it in? If we get KAFKA-3600 in, follow up changes to enable feature selection in clients should be pretty straight forward. > > 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 > -- Regards, Ashish
