Jay, Thank you for the feedback.
1. I think it is good to have a single concept of identity, but multiple ways of grouping clients for different functions. Client-id is a logical grouping of clients with a meaningful name that is used in client metrics and logs. User principal is an authenticated user or a grouping of unauthenticated users chosen by the broker and is used for ACLs. In my view, in a multi-user system, there is a hierarchy - user owns zero or more clients. (principal, client-id) defines a safe group, but the shorter unsafe client-id is sufficient in client metrics and logs. 2. KIP-55 was initially written to support hierarchical quotas (quotas for user1-clientA, user2-clientA etc), but Jun's view was that the complexity was not justified since there is no clear requirement for this. The cut-down version of the KIP is clearly a lot simpler. But I think your suggestion is to enable non-hierarchical user quotas and client-id quotas at the same time. Basically treat users and client-ids as distinct entities like topics and allow quotas to be applied to each of these entities. I agree that we want to support quotas simultaneously on different entities like topics and users. I am less convinced of client-id and user being distinct entities that require separate quotas at the same time. And treating client-id and user as distinct entities makes it harder to implement hierarchical quotas in future. A single user system needs only client-id quotas, and multi-tenant system cannot use client-id quotas since we need to guarantee that one tenant's quotas can never be used by another tenant. I suppose a multi-user cluster where users trust each other could apply separate quotas for both clients and users, but I am not sure if there is a usecase that can't be satisfied with just client-id based quotas for this case. Do you have a usecase in mind where you want to apply separate quotas for clients and users simultaneously? On Thu, Jun 9, 2016 at 9:40 PM, Jay Kreps <j...@confluent.io> wrote: > Super sorry to come in late on this one. Rajini, I had two quick questions > I think we should be able to answer: > > 1. Do client ids make sense in a world which has users? If not should we > unify them the way Hadoop did (without auth the user is a kind of best > effort honor system identity). This came up in the discussion thread > but I > didn't really see a crisp answer. Basically, what is the definition of > "client id" and what is the definition of "user" and how do the concepts > relate? > 2. If both client ids and users are sensible distinct notions and we > want to maintain both, why don't we just support quotas on both? If they > both make sense then you would have a reason to set quotas at both > levels. > Why have this "mode" that you set that swaps between only being able to > use > one and the other? I should be able to set quotas at both levels. Going > forward the model we had discussed with quotas was potentially being > able > to set quotas for many things independently (say at the topic level), > and I > don't think it would make sense to extend this mode approach to those. > > -Jay > > On Wed, Jun 8, 2016 at 12:56 PM, Rajini Sivaram < > rajinisiva...@googlemail.com> wrote: > > > I would like to initiate the vote for KIP-55. > > > > The KIP details are here: KIP-55: Secure quotas for authenticated users > > < > > > https://cwiki.apache.org/confluence/display/KAFKA/KIP-55%3A+Secure+Quotas+for+Authenticated+Users > > > > > . > > > > The JIRA KAFKA-3492 <https://issues.apache.org/jira/browse/KAFKA-3492 > > >has > > a draft PR here: https://github.com/apache/kafka/pull/1256. > > > > Thank you... > > > > Regards, > > > > Rajini > > > -- Regards, Rajini