Hi Jun, Few of my answers below (since these are things we discussed, or that I thought about)
On Mon, May 23, 2016 at 10:35 AM, Jun Rao <j...@confluent.io> wrote: > Thanks for the KIP. A few comments. > > 100. This potentially can be useful for Kafka Connect and Kafka rest proxy > where a worker agent will need to run a task on behalf of a client. We will > likely need to change how those services use Kafka clients > (producer/consumer). Instead of a shared client per worker, we will need a > client per user task since the authentication happens at the connection > level. For Kafka Connect, the renewer will be the workers. So, we probably > need to allow multiple renewers. For Kafka rest proxy, the renewer can > probably just be the creator of the token. > For the connector, the token for each connect task with be created by the connector that manages the task. It can also be responsible for renewing. > > 101. Do we need new acl on who can request delegation tokens? > We could, but I'd prefer not to have that. I can't see a use case of preventing certain users from delegating, since they can't delegate more than the privileges they already have. > > 102. Do we recommend people to send delegation tokens in an encrypted > channel? > Definitely. But just like SASL/PLAIN, we can leave both options open. > > 103. Who is responsible for expiring tokens, every broker? > I think token validity can be checked when they are used, like in SASL? > > 104. For invalidating tokens, would it be better to do it in a request > instead of going to ZK directly? > +1 to this. > > 105. The terminology of client in the wiki sometimes refers to the end > client and some other times refers to the client using the delegation > tokens. It would be useful to distinguish between the two. > > 106. Could you explain the sentence "Broker also stores the DelegationToken > without the hmac in the zookeeper." a bit more? I thought the delegation > token is the hmac. > > Thanks, > > Jun > > > On Mon, May 23, 2016 at 9:22 AM, Jun Rao <j...@confluent.io> wrote: > > > 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 > >> > > > >> >> > >> >> > > > >> > > > >> >> > >> >> > >> > > > >> >> > > >> > > > >> > >> > > > > >> > > > >> > >> > > >
