On Mon, Oct 12, 2015 at 5:42 PM, Jay Kreps <j...@confluent.io> wrote:
> Great. I definitely would strongly favor carrying over user's intuition > from FS unless we think we need a very different model. The minor details > like the seperator and namespace term will help with that. > > Follow-up question, say I have a layout like > /chicago-datacenter/user-events/pageviews > Can I subscribe to > /chicago-datacenter/user-events > Yes, however they will have need a regex like /chicago-datacenter/user-events/* > to get the full firehose of user events from chicago? Can I subscribe to > /*/user-events > to get user events originating from all datacenters? > Yes, however they will have need a regex like /chicago-datacenter/user-events/* Yes > > (Assuming, for now, that these are all in the same cluster...) > > Also, just to confirm, it sounds from the proposal like config overrides > would become fully hierarchical so you can override config at any directory > point. This will add complexity in implementation but I think will likely > be much more operator friendly. > Yes, that is the idea. > > There are about a thousand details to discuss in terms of how this would > impact the metadata request, various zk entries, and various other aspects, > but probably it makes sense to first agree on how we would want it to work > and then start to dive into how to implement that. > Agreed. > > -Jay > > On Mon, Oct 12, 2015 at 5:28 PM, Ashish Singh <asi...@cloudera.com> wrote: > > > Hey Jay, thanks for reviewing the proposal. Answers inline. > > > > On Mon, Oct 12, 2015 at 10:53 AM, Jay Kreps <j...@confluent.io> wrote: > > > > > Hey guys, > > > > > > I think this is an important feature and one we've talked about for a > > > while. I really think trying to invent a new nomenclature is going to > > make > > > it hard for people to understand, though. As such I recommend we call > > > namespaces "directories" and denote them with '/'--this will make the > > > feature 1000x more understandable to people. > > > > Essentially you are suggesting two things here. > > 1. Use "Directory" instead of "Namespace" as it is more intuitive. I > agree. > > 2. Make '/' as delimiter instead of ':'. Fine with me and I agree if we > > call these directories, '/' is the way to go. > > > > I think we should inheret the > > > semantics of normal unix fs in so far as it makes sense. > > > > > > In this approach we get rid of topics entirely, instead we really just > > have > > > partitions which are the equivalent of a file and retain their numeric > > > names, and the existing topic concept is just the first directory level > > but > > > we generalize to allow arbitrarily many more levels of nesting. This > > allows > > > categorization of data, such as /datacenter1/user-events/page-views/3 > and > > > you can subscribe, apply configs or permissions at any level of the > > > hierarchy. > > > > > +1. This actually requires just a minor change to existing proposal, > i.e., > > "some:namespace:topic" becomes "some/namespace/topic". > > > > > > > > I'm actually not 100% such what the semantics of accessing data in > > > differing namespaces is in the current proposal, maybe you can clarify > > > Ashish? > > > > I will add more info to KIP on this, however I think a client should be > > able to access data in any namespace as long as following conditions are > > satisfied. > > > > 1. Namespace, the client is trying to access, exists. > > 2. The client has sufficient permissions on the namespace for type of > > operation the client is trying to perform on a topic within that > namespace. > > 3. The client has sufficient permissions on the topic for type of > operation > > the client is trying to perform on that topic. > > > > If we choose to go with what you suggested earlier that just have > hierarchy > > of directories, then step 3 will actually be covered in step 2. > > > > In the current proposal, consumers will subscribe to a topic in a > namespace > > by specifying <namespace>:<topic> as the topic name. They can subscribe > to > > topics from multiple namespaces. > > > > Let me know if I totally missed your question. > > > > Since the point of Kafka is sharing data I think it is really > > > important that the grouping be just for > > convenience/permissions/config/etc > > > and that it remain possible to access multiple directories/namespaces > > from > > > the same client. > > > > > Totally agree with you. > > > > > > > > -Jay > > > > > > On Fri, Oct 9, 2015 at 6:32 PM, Ashish Singh <asi...@cloudera.com> > > wrote: > > > > > > > Hey Guys, > > > > > > > > I just created KIP-37 for adding namespaces to Kafka. > > > > > > > > KIP-37 > > > > < > > > > > > > > > > https://cwiki.apache.org/confluence/display/KAFKA/KIP-37+-+Add+Namespaces+to+Kafka > > > > > > > > > tracks the proposal. > > > > > > > > The idea is to make Kafka support multi-tenancy via namespaces. > > > > > > > > Feedback and comments are welcome. > > > > > > > > -- > > > > > > > > Regards, > > > > Ashish > > > > > > > > > > > > > > > -- > > > > Regards, > > Ashish > > > -- Regards, Ashish
