[keycloak-dev] sticky sessions, clustering, and authentication

[Stian Thorgersen]

----- Original Message -----
> From: "Marek Posolda" <mposolda at redhat.com>
> To: "Stian Thorgersen" <stian at redhat.com>
> Cc: "mike cirioli" <mikecirioli at gmail.com>, "Bill Burke" <bburke at redhat.com>, keycloak-dev at lists.jboss.org
> Sent: Thursday, 4 June, 2015 10:28:15 AM
> Subject: Re: [keycloak-dev] sticky sessions, clustering, and authentication
> 
> On 4.6.2015 08:53, Stian Thorgersen wrote:
> >
> > ----- Original Message -----
> >> From: "Marek Posolda" <mposolda at redhat.com>
> >> To: "mike cirioli" <mikecirioli at gmail.com>, "Bill Burke"
> >> <bburke at redhat.com>
> >> Cc: keycloak-dev at lists.jboss.org
> >> Sent: Thursday, 4 June, 2015 8:49:03 AM
> >> Subject: Re: [keycloak-dev] sticky sessions, clustering, and
> >> authentication
> >>
> >> Question is if the requirement for sticky sessions is not too
> >> restrictive? I guess not everyone want to use sticky sessions.
> >>
> >> Maybe we should offer both possibilities (in-memory + sticky sessions OR
> >> AuthenticationSession saved in infinispan and replicated after each
> >> request) ?
> >>
> >> Another question is if overhead of current replication is really so bad
> >> to introduce another abstraction and increase code complexity?
> > We're not using a replicated cache - we're using a distributed cache.
> >
> > If anyone is worried about performance Google how Google works (hint:
> > sharding) ;)
> yeah, the performance is the question and at some point I want to look
> at it a bit more. For the distributed I am a bit worried if it doesn't
> require more network calls then replicated in some envs. I wonder about
> the situation like:
> 
> 1) You open login screen and you're forwarded by LB to node1 where is
> ClientSession created and saved into cache
> 2) You confirm login screen but then you're forwarded by LB to node2.
> Then call to "keycloakSession.sessions().getClientSession()" always
> perform network call to node1 as my ClientSession is saved on node1. Or
> am I wrong here?
> 
> So in shortcut, in distribution there is no any overhead with
> replicating the session as it's saved always in one node, but there may
> be much more overhead in lookup for sessions, which are saved on
> different cluster node (unless I am wrong...)

Sticky sessions are horrible and hard to get to work for Keycloak especially as we have two separate calls (browser and app).

Only solution without sticky sessions are distributed caches (shards). If Google can make it scale to their level it shouldn't be a problem for us either.

What we do maybe need to optimize is how many calls there are. For example atm I think we call once to get client session and another for user session.

> 
> Marek
> 
> >
> >> Marek
> >>
> >> On 4.6.2015 01:49, mike cirioli wrote:
> >>> So sticky sessions would be needed only during the authentication phase,
> >>> and once complete an underlying clustered session would be created?
> >>>
> >>> On Jun 3, 2015 7:00 PM, Bill Burke <bburke at redhat.com> wrote:
> >>>> I was thinking a bit about performance in a cluster.  Right now a client
> >>>> session is created whenever login is initiated.  This ends up requiring
> >>>> the client session to be propagated to the cluster, either through a
> >>>> database insert/update or an infinispan replication.  Then, with each
> >>>> authentication/required action step, another insert/update/replication.
> >>>>
> >>>> I was thinking we should have an AuthenticationSession that was in
> >>>> memory only.  Then, once all authentication and required actions are
> >>>> finished, then create the usersession and client session.  This would
> >>>> require sticky sessions though with a load balancer.
> >>>>
> >>>> --
> >>>> Bill Burke
> >>>> JBoss, a division of Red Hat
> >>>> http://bill.burkecentral.com
> >>>> _______________________________________________
> >>>> keycloak-dev mailing list
> >>>> keycloak-dev at lists.jboss.org
> >>>> https://lists.jboss.org/mailman/listinfo/keycloak-dev
> >>> _______________________________________________
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> >>
> 
>