Makes sense to me. Thanks!
On Mon, Mar 7, 2016 at 9:25 PM, Harsha <ka...@harsha.io> wrote:
> It doesn't need any release vehicle but still the work can move forward.
> If anyone is interested in the KIP please do the review and provide the
> comments.
>
> -Harsha
>
> On Mon, Mar 7, 2016, at 04:59 PM, Ismael Juma wrote:
>> I agree that it would be good to have more time to review and discuss
>> KIP-48.
>>
>> Ismael
>>
>> On Tue, Mar 8, 2016 at 12:55 AM, Gwen Shapira <g...@confluent.io> wrote:
>>
>> > Hi Team,
>> >
>> > Since KIP-48 depends on KIP-43, which is already a bit of a risk for
>> > the next release - any chance we can delay delegation tokens to Kafka
>> > 0.10.1?
>> > With the community working on a release every 3 month, this is not a huge
>> > delay.
>> >
>> > Gwen
>> >
>> > On Fri, Feb 26, 2016 at 5:11 PM, Ashish Singh <asi...@cloudera.com> wrote:
>> > > Parth,
>> > >
>> > > Thanks again for the awesome write up. Following our discussion from the
>> > > JIRA, I think it will be easier to compare various alternatives if they
>> > are
>> > > listed together. I am stating below a few alternatives along with a the
>> > > current proposal.
>> > > (Current proposal) Store Delegation Token, DT, on ZK.
>> > >
>> > > 1. Client authenticates with a broker.
>> > > 2. Once a client is authenticated, it will make a broker side call to
>> > > issue a delegation token.
>> > > 3. The broker generates a shared secret based on HMAC-SHA256(a
>> > > Password/Secret shared between all brokers, randomly generated
>> > tokenId).
>> > > 4. Broker stores this token in its in memory cache. Broker also stores
>> > > the DelegationToken without the hmac in the zookeeper.
>> > > 5. All brokers will have a cache backed by zookeeper so they will all
>> > > get notified whenever a new token is generated and they will update
>> > their
>> > > local cache whenever token state changes.
>> > > 6. Broker returns the token to Client.
>> > >
>> > > Probable issues and fixes
>> > >
>> > > 1. Probable race condition, client tries to authenticate with a broker
>> > > that is yet to be updated with the newly generated DT. This can
>> > probably be
>> > > dealt with making dtRequest block until all brokers have updated
>> > their DT
>> > > cache. Zk barrier or similar mechanism can be used. However, all such
>> > > mechanisms will increase complexity.
>> > > 2. Using a static secret key from config file. Will require yet
>> > another
>> > > config and uses a static secret key. It is advised to rotate secret
>> > keys
>> > > periodically. This can be avoided with controller generating
>> > secretKey and
>> > > passing to brokers periodically. However, this will require brokers to
>> > > maintain certain counts of secretKeys.
>> > >
>> > > (Alternative 1) Have controller generate delegation token.
>> > >
>> > > 1. Client authenticates with a broker.
>> > > 2. Once a client is authenticated, it will make a broker side call to
>> > > issue a delegation token.
>> > > 3. Broker forwards the request to controller.
>> > > 4. Controller generates a DT and broadcasts to all brokers.
>> > > 5. Broker stores this token in its memory cache.
>> > > 6. Controller responds to broker’s DT req.
>> > > 7. Broker returns the token to Client.
>> > >
>> > > Probable issues and fixes
>> > >
>> > > 1. We will have to add new APIs to support controller pushing tokens
>> > to
>> > > brokers on top of the minimal APIs that are currently proposed.
>> > > 2. We will also have to add APIs to support the bootstrapping case,
>> > i.e,
>> > > when a new broker comes up it will have to get all delegation tokens
>> > from
>> > > the controller.
>> > > 3. In catastrophic failures where all brokers go down, the tokens will
>> > > be lost even if servers are restarted as tokens are not persisted
>> > anywhere.
>> > > If this happens, then there are more important things to worry about
>> > and
>> > > maybe it is better to re-authenticate.
>> > >
>> > > (Alternative 2) Do not distribute DT to other brokers at all.
>> > >
>> > > 1. Client authenticates with a broker.
>> > > 2. Once a client is authenticated, it will make a broker side call to
>> > > issue a delegation token.
>> > > 3. The broker generates DT of form, [hmac + (owner, renewer,
>> > > maxLifeTime, id, hmac, expirationTime)] and passes back this DT to
>> > client.
>> > > hmac is generated via {HMAC-SHA256(owner, renewer, maxLifeTime, id,
>> > hmac,
>> > > expirationTime) using SecretKey}. Note that all brokers have this
>> > SecretKey.
>> > > 4. Client then goes to any broker and to authenticate sends the DT.
>> > > Broker recalculates hmac using (owner, renewer, maxLifeTime, id, hmac,
>> > > expirationTime) info from DT and its SecretKey. If it matches with
>> > hmac of
>> > > DT, client is authenticated. Yes, it will do other obvious checks of
>> > > timestamp expiry and such.
>> > >
>> > > Note that secret key will be generated by controller and passed to
>> > brokers
>> > > periodically.
>> > > Probable issues and fixes
>> > >
>> > > 1. How to delete a DT? Yes, that is a downside here. However, this can
>> > > be handled with brokers maintaining a blacklist of DTs, DTs from this
>> > list
>> > > can be removed after expiry.
>> > > 2. In catastrophic failures where all brokers go down, the tokens will
>> > > be lost even if servers are restarted as tokens are not persisted
>> > anywhere.
>> > > If this happens, then there are more important things to worry about
>> > and
>> > > maybe it is better to re-authenticate.
>> > >
>> > >
>> > >
>> > > On Fri, Feb 26, 2016 at 1:58 PM, Parth Brahmbhatt <
>> > > pbrahmbh...@hortonworks.com> wrote:
>> > >
>> > >> Hi,
>> > >>
>> > >> I have filed KIP-48 so we can offer hadoop like delegation tokens in
>> > >> kafka. You can review the design
>> > >>
>> > https://cwiki.apache.org/confluence/display/KAFKA/KIP-48+Delegation+token+support+for+Kafka
>> > .
>> > >> This KIP depends on KIP-43 and we have also discussed an alternative to
>> > >> proposed design here<
>> > >>
>> > https://issues.apache.org/jira/browse/KAFKA-1696?focusedCommentId=15167800&page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel#comment-15167800
>> > >> >.
>> > >>
>> > >> Thanks
>> > >> Parth
>> > >>
>> > >
>> > >
>> > >
>> > > --
>> > >
>> > > Regards,
>> > > Ashish
>> >
