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 > >