Hi, Harsha, Just sent out a KIP meeting invite. We can discuss this in the meeting tomorrow.
Thanks, Jun On Thu, May 19, 2016 at 8:47 AM, Harsha <ka...@harsha.io> wrote: > Hi All, > Can we have a KIP meeting around this. The KIP is up for > sometime and if there are any questions lets quickly hash out > details. > > Thanks, > Harsha > > On Thu, May 19, 2016, at 08:40 AM, parth brahmbhatt wrote: > > That is what the hadoop echo system uses so no good reason really. We > > could > > change it to whatever is the newest recommended standard is. > > > > Thanks > > Parth > > > > On Thu, May 19, 2016 at 3:33 AM, Ismael Juma <ism...@juma.me.uk> wrote: > > > > > Hi Parth, > > > > > > Thanks for the KIP. I only started reviewing this and may have > additional > > > questions later. The immediate question that came to mind is our > choice of > > > "DIGEST-MD5" even though it's marked as OBSOLETE in the IANA Registry > of > > > SASL mechanisms and the original RFC (2831) has been moved to Historic > > > status: > > > > > > https://tools.ietf.org/html/rfc6331 > > > http://www.iana.org/assignments/sasl-mechanisms/sasl-mechanisms.xhtml > > > > > > What is the reasoning behind that choice? > > > > > > Thanks, > > > Ismael > > > > > > On Fri, May 13, 2016 at 11:29 PM, Gwen Shapira <g...@confluent.io> > wrote: > > > > > > > Also comments inline :) > > > > > > > > > * I want to emphasize that even though delegation tokens are a > Hadoop > > > > > innovation, I feel very strongly about not adding dependency on > Hadoop > > > > > when implementing delegation tokens for Kafka. The KIP doesn't > imply > > > > > such dependency, but if you can clarify... > > > > > > > > > > > > > > > *No hadoop dependency.* > > > > > > > > Yay! Just add this to the KIP so no one will read the KIP and panic > > > > three weeks before the next release... > > > > > > > > > * Can we get delegation token at any time after authenticating? > only > > > > > immediately after? > > > > > > > > > > > > > > > *As long as you are authenticated you can get delegation tokens. We > > > need > > > > to > > > > > discuss if a client authenticated using delegation token, can also > > > > acquire > > > > > delegation token again or not. Also there is the question of do we > > > allow > > > > > anyone to acquire delegation token or we want specific ACLs (I > think > > > its > > > > an > > > > > overkill.)* > > > > > > > > I agree that ACLs is an overkill. > > > > > > > > I think we are debating two options: Either require Kerberos auth for > > > > renewal or require non-owners to renew. > > > > I *think* the latter is simpler (it basically require a "job master" > > > > to take responsibility for the renewal, it will have its own identity > > > > anyway and I think this is the correct design pattern anyway. For > > > > storm, I'd expect Nimbus to coordinate renewals?), but it is hard to > > > > debate simplicity without looking at the code changes required. If > you > > > > have a draft of how the "require Kerberos" will look in Kafka code, > > > > I'll be happy to take a look. > > > > > > > > > * My understanding is that tokens will propagate via ZK but without > > > > > additional changes to UpdateMetadata protocol, correct? Clients > > > > > currently don't retry on SASL auth failure (IIRC), but since the > > > > > tokens propagate between brokers asynch, we will need to retry a > bit > > > > > to avoid clients failing auth due to timing issues. > > > > > > > > > > *I am considering 2 alternatives right now. The current documented > > > > approach > > > > > is zookeeper based and it does not require any changes to > > > UpdateMetadata > > > > > protocol. An alternative approach can remove zookeeper dependency > as > > > well > > > > > but we can discuss that in KIP discussion call.* > > > > > > > > Oooh! Sounds interesting. Do you want to ping Jun to arrange a call? > > > > > > > > > * I liked Ashish's suggestion of having just the controller issue > the > > > > > delegation tokens, to avoid syncing a shared secret. Not sure if we > > > > > want to continue the discussion here or on the wiki. I think that > we > > > > > can decouple the problem of "token distribution" from "shared > secret > > > > > distribution" and use the controller as the only token generator to > > > > > solve the second issue, while still using ZK async to distribute > > > > > tokens. > > > > > > > > > > > > > > > *As mentioned in the previous Email I am fine with that approach as > > > long > > > > as > > > > > we agree that the extra complexity of adding/updating APIS adds > enough > > > > > value. The advantage with the controller approach is secret > rotation > > > can > > > > be > > > > > automated,frequent and would not require deployment. * > > > > > > > > Can you detail the extra complexity (or point me to the email I > > > > missed?) - which Apis are required? > > > > As far as I can tell, clients can already find the controller from > > > > metadata. I'm a bit more concerned about controller load. > > > > > > > > > > > > > > * While I like the idea of forcing kerberos auth for renwal, I > think > > > > > it mixes the transport layer the the request content in a pretty > ugly > > > > > way. Perhaps limiting renewer to non-owner is better. > > > > > > > > > > *I feel this is a necessary evil. While this will make the kafka > code > > > > > pretty straight forward , forcing renewer to non-owner pushes the > code > > > > > ugliness to client and makes it even harder to integrate. * > > > > > > > > As mentioned before, I don't think the "renewal by other" approach is > > > > that ugly for the clients we expect to use delegation tokens since > > > > they will have an app-master of some sort who requested the token to > > > > begin with. > > > > > > > > > > > > > > The response for my question on how multiple identities will be > > > > > handled wasn't super clear to me - AFAIK, we don't authenticate > each > > > > > request, we authenticate connections. > > > > > > > > > > *We authenticate connections, and only when they are being > established. > > > > Let > > > > > me try to phrase this as a question, in absence of delegation > tokens if > > > > we > > > > > had to support the use case using user TGT's how would we do it? My > > > point > > > > > was it would be no different with delegation tokens. The use case > you > > > are > > > > > describing seems more like impersonation.* > > > > > > > > Yeah, I thought that one of the things that delegation tokens > handled. > > > > Maybe I got it wrong :) > > > > > > > > Thanks for the detailed answers. > > > > > > > > Gwen > > > > > > > > > > > > > Thanks > > > > > Parth > > > > > > > > > > On Fri, May 13, 2016 at 12:19 AM, Gwen Shapira <g...@confluent.io> > > > > wrote: > > > > > > > > > >> Hi Parth and Harsha, > > > > >> > > > > >> Few more comments: > > > > >> > > > > >> * The API / RequestResponse section doesn't seem to have good > > > > >> description of the changes to the Kafka Protocol. Sounds like you > are > > > > >> proposing new DelegationTokenRequest and RenewTokenRequest (and > > > > >> matching responses), without detailing the contents of the > requests > > > > >> and responses? Or rather, you show the class interface, but not > the > > > > >> underlying protocol. This could be seen as an implementation > detail, > > > > >> but since the binary protocol is what we provide to non-Java > clients, > > > > >> we need to show the changes there. > > > > >> > > > > >> * getDelegationToken sounds like delegationTokenRequestHandler? > Is it > > > > >> planned to be part of KafkaApi? or Client? Its unclear... > > > > >> > > > > >> * I want to emphasize that even though delegation tokens are a > Hadoop > > > > >> innovation, I feel very strongly about not adding dependency on > Hadoop > > > > >> when implementing delegation tokens for Kafka. The KIP doesn't > imply > > > > >> such dependency, but if you can clarify... > > > > >> > > > > >> * Can we get delegation token at any time after authenticating? > only > > > > >> immediately after? > > > > >> > > > > >> * My understanding is that tokens will propagate via ZK but > without > > > > >> additional changes to UpdateMetadata protocol, correct? Clients > > > > >> currently don't retry on SASL auth failure (IIRC), but since the > > > > >> tokens propagate between brokers asynch, we will need to retry a > bit > > > > >> to avoid clients failing auth due to timing issues. > > > > >> > > > > >> * Strongly agreeing on clients not touching ZK directly :) > > > > >> > > > > >> * I liked Ashish's suggestion of having just the controller issue > the > > > > >> delegation tokens, to avoid syncing a shared secret. Not sure if > we > > > > >> want to continue the discussion here or on the wiki. I think that > we > > > > >> can decouple the problem of "token distribution" from "shared > secret > > > > >> distribution" and use the controller as the only token generator > to > > > > >> solve the second issue, while still using ZK async to distribute > > > > >> tokens. > > > > >> > > > > >> * I am also uncomfortable with infinite lifetime of tokens (and > hoped > > > > >> to hear from others in the community) - but having the option and > > > > >> documenting it as less secure, allows users to configure their > system > > > > >> as the wish. > > > > >> > > > > >> * While I like the idea of forcing kerberos auth for renwal, I > think > > > > >> it mixes the transport layer the the request content in a pretty > ugly > > > > >> way. Perhaps limiting renewer to non-owner is better. > > > > >> > > > > >> Things I'd still like to see: > > > > >> > > > > >> * More detailed explanation on what we plan to do for the java > clients > > > > >> specifically - new configuration? new APIs? > > > > >> The response for my question on how multiple identities will be > > > > >> handled wasn't super clear to me - AFAIK, we don't authenticate > each > > > > >> request, we authenticate connections. > > > > >> > > > > >> * Alternatives: Delegation tokens are only used in the Hadoop > > > > >> ecosystem. I'm wondering if there are alternatives in other > ecosystems > > > > >> (Mesos? Tachyon? Cassandra?) and whether there are some advantages > > > > >> there. > > > > >> > > > > >> Gwen > > > > >> > > > > >> On Thu, May 12, 2016 at 1:05 PM, Harsha <ka...@harsha.io> wrote: > > > > >> > Hi Gwen, > > > > >> > Can you look at Parth's last reply. Does it answer > your > > > > >> > concerns. > > > > >> > > > > > >> > Thanks, > > > > >> > Harsha > > > > >> > > > > > >> > On Wed, May 4, 2016, at 09:25 AM, parth brahmbhatt wrote: > > > > >> >> Thanks for reviewing Gwen. The wiki already has details on > token > > > > >> >> expiration > > > > >> >> under token acquisition process > > > > >> >> < > > > > >> > > > > > > > > https://cwiki.apache.org/confluence/display/KAFKA/KIP-48+Delegation+token+support+for+Kafka#KIP-48DelegationtokensupportforKafka-Tokenacquisition > > > > >> >. > > > > >> >> Current proposal is that tokens will expire based on a server > side > > > > >> >> configuration (default 24 hours) unless renewed. Renewal is > only > > > > allowed > > > > >> >> until the max life time of token. Alternatively we could also > make > > > > that > > > > >> >> an > > > > >> >> optional param and the server side default can serve as the > upper > > > > bound. > > > > >> >> > > > > >> >> To your second point it will be done exactly the same way we > would > > > > >> >> support > > > > >> >> multiple keytabs. The calling client will have to put the > tokens it > > > > >> wants > > > > >> >> to use in the subject instance and call produce/consume inside > > > > >> >> subject.doas. Each caller will have to keep track of its own > > > > subject. I > > > > >> >> will have to look at the code to see if we support this feature > > > right > > > > >> now > > > > >> >> but my understanding is delegation token shouldn't need any > special > > > > >> >> treatment as its just another type of Credential in the > subject. > > > > >> >> > > > > >> >> I would also like to know what is your opinion about infinite > > > renewal > > > > >> (my > > > > >> >> recommendation is to not support this), tokens renewing them > > > self(my > > > > >> >> recommendation is to not support this) and most importantly > your > > > > choice > > > > >> >> between the alternatives listed on this thread > > > > >> >> < > > > > >> > > > > > > > > http://apache.markmail.org/message/ca3iakt3m6c4yygp?q=KIP-48+Support+for+delegation+tokens+as+an+authentication+mechanism > > > > >> > > > > > >> >> ( I am leaning towards the alternative-2 minus controller > > > > distributing > > > > >> >> secret). Thanks again for reviewing. > > > > >> >> > > > > >> >> Thanks > > > > >> >> Parth > > > > >> >> > > > > >> >> > > > > >> >> > > > > >> >> On Wed, May 4, 2016 at 6:17 AM, Gwen Shapira < > g...@confluent.io> > > > > wrote: > > > > >> >> > > > > >> >> > Harsha, > > > > >> >> > > > > > >> >> > I was thinking of the Rest Proxy. I didn't see your design > yet, > > > > but in > > > > >> >> > our proxy, we have a set of producers, which will serve > multiple > > > > users > > > > >> >> > going through the proxy. Since these users will have > different > > > > >> >> > privileges, they'll need to authenticate separately, and > can't > > > > share a > > > > >> >> > token. > > > > >> >> > > > > > >> >> > Am I missing anything? > > > > >> >> > > > > > >> >> > Gwen > > > > >> >> > > > > > >> >> > On Tue, May 3, 2016 at 2:11 PM, Harsha <ka...@harsha.io> > wrote: > > > > >> >> > > Gwen, > > > > >> >> > > On your second point. Can you describe a usecase > > > where > > > > >> >> > > mutliple clients ended up sharing a producer and > > > even > > > > if > > > > >> they > > > > >> >> > > do why can't they not use single token that > producer > > > > >> >> > > captures. Why would we need multiple clients > with > > > > >> different > > > > >> >> > > tokens sharing a single instance of producer. > Also > > > in > > > > >> this > > > > >> >> > > case other clients have access all the tokens > no? > > > > >> >> > > > > > > >> >> > > Thanks, > > > > >> >> > > Harsha > > > > >> >> > > > > > > >> >> > > > > > > >> >> > > On Tue, May 3, 2016, at 11:49 AM, Gwen Shapira wrote: > > > > >> >> > >> Sorry for the delay: > > > > >> >> > >> > > > > >> >> > >> Two questions that we didn't see in the wiki: > > > > >> >> > >> 1. Is there an expiration for delegation tokens? Renewal? > How > > > > do we > > > > >> >> > >> revoke them? > > > > >> >> > >> 2. If we want to use delegation tokens for "do-as" (say, > > > submit > > > > >> Storm > > > > >> >> > >> job as my user), we will need a producer for every job (we > > > can't > > > > >> share > > > > >> >> > >> them between multiple jobs running on same node), since we > > > only > > > > >> >> > >> authenticate when connecting. Is there a plan to change > this > > > for > > > > >> >> > >> delegation tokens, in order to allow multiple users with > > > > different > > > > >> >> > >> tokens to share a client? > > > > >> >> > >> > > > > >> >> > >> Gwen > > > > >> >> > >> > > > > >> >> > >> On Tue, May 3, 2016 at 9:12 AM, parth brahmbhatt > > > > >> >> > >> <brahmbhatt.pa...@gmail.com> wrote: > > > > >> >> > >> > Bumping this up one more time, can other committers > review? > > > > >> >> > >> > > > > > >> >> > >> > Thanks > > > > >> >> > >> > Parth > > > > >> >> > >> > > > > > >> >> > >> > On Tue, Apr 26, 2016 at 9:07 AM, Harsha < > ka...@harsha.io> > > > > wrote: > > > > >> >> > >> > > > > > >> >> > >> >> Parth, > > > > >> >> > >> >> Overall current design looks good to me. I > am +1 > > > on > > > > >> the > > > > >> >> > KIP. > > > > >> >> > >> >> > > > > >> >> > >> >> Gwen , Jun can you review this as well. > > > > >> >> > >> >> > > > > >> >> > >> >> -Harsha > > > > >> >> > >> >> > > > > >> >> > >> >> On Tue, Apr 19, 2016, at 09:57 AM, parth brahmbhatt > wrote: > > > > >> >> > >> >> > Thanks for review Jitendra. > > > > >> >> > >> >> > > > > > >> >> > >> >> > I don't like the idea of infinite lifetime but I see > the > > > > >> Streaming > > > > >> >> > use > > > > >> >> > >> >> > case. Even for Streaming use case I was hoping there > will > > > > be > > > > >> some > > > > >> >> > notion > > > > >> >> > >> >> > of > > > > >> >> > >> >> > master/driver that can get new delegation tokens at > fixed > > > > >> interval > > > > >> >> > and > > > > >> >> > >> >> > distribute to workers. If that is not the case for > we can > > > > >> discuss > > > > >> >> > >> >> > delegation tokens renewing them self and the security > > > > >> implications > > > > >> >> > of the > > > > >> >> > >> >> > same. > > > > >> >> > >> >> > > > > > >> >> > >> >> > I did not want clients to fetch tokens from > zookeeper, > > > > >> overall I > > > > >> >> > think > > > > >> >> > >> >> > its > > > > >> >> > >> >> > better if clients don't rely on our metadata store > and I > > > > >> think we > > > > >> >> > are > > > > >> >> > >> >> > moving in that direction with all the KIP-4 > improvements. > > > > I > > > > >> chose > > > > >> >> > >> >> > zookeeper as in this case the client will still just > talk > > > > to > > > > >> >> > broker , its > > > > >> >> > >> >> > the brokers that will use zookeeper which we already > do > > > > for a > > > > >> lot > > > > >> >> > of > > > > >> >> > >> >> > other > > > > >> >> > >> >> > usecases + ease of development + and the ability so > > > tokens > > > > >> will > > > > >> >> > survive > > > > >> >> > >> >> > even a rolling restart/cluster failure. if a majority > > > > agrees > > > > >> the > > > > >> >> > added > > > > >> >> > >> >> > complexity to have controller forwarding keys to all > > > > broker is > > > > >> >> > justified > > > > >> >> > >> >> > as > > > > >> >> > >> >> > it provides tighter security , I am fine with that > option > > > > too. > > > > >> >> > >> >> > > > > > >> >> > >> >> > Given zookeeper does not support SSL we can not store > > > > master > > > > >> keys > > > > >> >> > in > > > > >> >> > >> >> > zookeeper as master keys will be exposed on wire. To > > > > support > > > > >> >> > rotation > > > > >> >> > >> >> > without affecting current clients is something I > need to > > > > put > > > > >> more > > > > >> >> > thought > > > > >> >> > >> >> > in. My current proposal assumes the rotation will > > > > invalidate > > > > >> all > > > > >> >> > current > > > > >> >> > >> >> > tokens. > > > > >> >> > >> >> > > > > > >> >> > >> >> > I request committers to also review and post their > > > comments > > > > >> so we > > > > >> >> > can > > > > >> >> > >> >> > make > > > > >> >> > >> >> > progress on this KIP. > > > > >> >> > >> >> > > > > > >> >> > >> >> > Thanks > > > > >> >> > >> >> > Parth > > > > >> >> > >> >> > > > > > >> >> > >> >> > On Tue, Apr 19, 2016 at 8:39 AM, Ashish Singh < > > > > >> asi...@cloudera.com > > > > >> >> > > > > > > >> >> > >> >> > wrote: > > > > >> >> > >> >> > > > > > >> >> > >> >> > > On Mon, Apr 18, 2016 at 11:26 AM, Harsha < > > > > ka...@harsha.io> > > > > >> >> > wrote: > > > > >> >> > >> >> > > > > > > >> >> > >> >> > > > Unifying the two discussion threads on this KIP. > > > > >> >> > >> >> > > > > > > > >> >> > >> >> > > > Here is the response from Jitendra > > > > >> >> > >> >> > > > > > > > >> >> > >> >> > > > "The need for a large number of clients that are > > > > running > > > > >> all > > > > >> >> > over the > > > > >> >> > >> >> > > > cluster that authenticate with Kafka brokers, is > very > > > > >> similar > > > > >> >> > to the > > > > >> >> > >> >> > > > Hadoop use case of large number of tasks running > > > across > > > > >> the > > > > >> >> > cluster > > > > >> >> > >> >> that > > > > >> >> > >> >> > > > need authentication to Hdfs Namenode. Therefore, > the > > > > >> >> > delegation token > > > > >> >> > >> >> > > > approach does seem like a good fit for this use > case > > > > as we > > > > >> >> > have seen > > > > >> >> > >> >> it > > > > >> >> > >> >> > > > working at large scale in HDFS and YARN. > > > > >> >> > >> >> > > > > > > > >> >> > >> >> > > > The proposed design is very much inline with > Hadoop > > > > >> >> > approach. A few > > > > >> >> > >> >> > > > comments: > > > > >> >> > >> >> > > > > > > > >> >> > >> >> > > > 1) Why do you guys want to allow infinite > renewable > > > > >> lifetime > > > > >> >> > for a > > > > >> >> > >> >> > > > token? HDFS restricts a token to a max life time > > > > (default > > > > >> 7 > > > > >> >> > days). A > > > > >> >> > >> >> > > > token's vulnerability is believed to increase > with > > > > time. > > > > >> >> > >> >> > > > > > > > >> >> > >> >> > > I agree that having infinite lifetime might not be > the > > > > best > > > > >> idea. > > > > >> >> > >> >> > > > > > > >> >> > >> >> > > > > > > > >> >> > >> >> > > > 2) As I understand the tokens are stored in > zookeeper > > > > as > > > > >> well, > > > > >> >> > and > > > > >> >> > >> >> can > > > > >> >> > >> >> > > > be updated there. This is clever as it can allow > > > > >> replacing the > > > > >> >> > tokens > > > > >> >> > >> >> > > > once they run out of max life time, and clients > can > > > > >> download > > > > >> >> > new > > > > >> >> > >> >> tokens > > > > >> >> > >> >> > > > from zookeeper. It shouldn't be a big load on > > > zookeeper > > > > >> as a > > > > >> >> > client > > > > >> >> > >> >> will > > > > >> >> > >> >> > > > need to get a new token once in several days. In > this > > > > >> approach > > > > >> >> > you > > > > >> >> > >> >> don't > > > > >> >> > >> >> > > > need infinite lifetime on the token even for long > > > > running > > > > >> >> > clients. > > > > >> >> > >> >> > > > > > > > >> >> > >> >> > > > 3) The token password are generated using a > master > > > key. > > > > >> The > > > > >> >> > master > > > > >> >> > >> >> key > > > > >> >> > >> >> > > > should also be periodically changed. In Hadoop, > the > > > > >> default > > > > >> >> > renewal > > > > >> >> > >> >> > > > period is 1 day.? > > > > >> >> > >> >> > > > > > > > >> >> > >> >> > > IIUC, this will require brokers maintaining a list > of X > > > > most > > > > >> >> > recent > > > > >> >> > >> >> master > > > > >> >> > >> >> > > keys. This list will have to be persisted > somewhere, as > > > > if a > > > > >> >> > broker > > > > >> >> > >> >> goes > > > > >> >> > >> >> > > down it will have to get that list again and > storing > > > > master > > > > >> keys > > > > >> >> > on ZK > > > > >> >> > >> >> is > > > > >> >> > >> >> > > not the best idea. However, if a broker goes down > then > > > we > > > > >> have > > > > >> >> > much > > > > >> >> > >> >> bigger > > > > >> >> > >> >> > > issue to deal with and client can always > > > re-authenticate > > > > is > > > > >> such > > > > >> >> > >> >> events. > > > > >> >> > >> >> > > > > > > >> >> > >> >> > > Did you happen to take a look at other alternatives > > > this > > > > >> list has > > > > >> >> > >> >> > > suggested? > > > > >> >> > >> >> > > > > > > >> >> > >> >> > > > > > > > >> >> > >> >> > > > Thanks for a thorough proposal, great work!" > > > > >> >> > >> >> > > > > > > > >> >> > >> >> > > > > > > > >> >> > >> >> > > > > > > > >> >> > >> >> > > > On Mon, Mar 7, 2016, at 10:28 PM, Gwen Shapira > wrote: > > > > >> >> > >> >> > > > > 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 > > > > >> >> > >> >> > > > > >> > > > > > >> >> > >> >> > > > > > > > >> >> > >> >> > > > > > > >> >> > >> >> > > > > > > >> >> > >> >> > > > > > > >> >> > >> >> > > -- > > > > >> >> > >> >> > > > > > > >> >> > >> >> > > Regards, > > > > >> >> > >> >> > > Ashish > > > > >> >> > >> >> > > > > > > >> >> > >> >> > > > > >> >> > > > > > >> > > > > > > > > >
