[keycloak-user] Does Keycloak need sticky session at the load balancer?

Rafael Weingärtner rafaelweingartner at gmail.com
Thu Aug 30 07:02:45 EDT 2018


Awesome, thanks for the help, Sebastian. I have a question regarding these
"owners" numbers. What happens if I set this number to (let's say) 10 and I
only spin up 7 nodes? Is it a valid deployment? And, will everything work
just fine? Or, would I start to get errors?



On Thu, Aug 30, 2018 at 5:02 AM, Sebastian Laskawiec <slaskawi at redhat.com>
wrote:

> On Wed, Aug 29, 2018 at 3:27 PM Rafael Weingärtner <
> rafaelweingartner at gmail.com> wrote:
>
>> I think I will need a little bit of your wisdom again.
>>
>> I am now seeing the cluster between my Keycloak replicas to be created:
>>
>>> ^[[0m^[[0m13:03:03,800 INFO  [org.infinispan.remoting.transport.jgroups.JGroupsTransport]
>>> (MSC service thread 1-2) ISPN000079: Channel ejb local address is
>>> keycloak01, physical addresses are [192.168.1.58:55200]
>>> ^[[0m^[[0m13:03:03,801 INFO  [org.infinispan.remoting.transport.jgroups.JGroupsTransport]
>>> (MSC service thread 1-1) ISPN000094: Received new cluster view for channel
>>> ejb: [keycloak02|1] (2) [keycloak02, keycloak01]
>>>
>>
>> The problem is that when I shutdown one of them, a logged user will
>> receive the following message:
>>
>>> An internal server error has occurred
>>>
>>
>>
>> Then, in the log files I see the following:
>>
>>> ^[[0m^[[31m13:18:04,149 ERROR [org.infinispan.interceptors.InvocationContextInterceptor]
>>> (default task-24) ISPN000136: Error executing command GetKeyValueCommand,
>>> writing keys []: org.infinispan.util.concurrent.TimeoutException:
>>> Replication timeout
>>>         at org.infinispan.remoting.transport.jgroups.
>>> JGroupsTransport.lambda$invokeRemotelyAsync$1(JGroupsTransport.java:639)
>>> ^[[0m^[[31m13:18:15,262 ERROR [org.infinispan.interceptors.InvocationContextInterceptor]
>>> (expiration-thread--p22-t1) ISPN000136: Error executing command
>>> RemoveExpiredCommand, writing keys [468d1940-7293-4824-9e86-4aece6cd6744]:
>>> org.infinispan.util.concurrent.TimeoutException: Replication timeout
>>> for keycloak02
>>>
>>
> I see you just killed the node (e.g. kill -9 <pid>), so that it exited
> without saying "goodbye". In that case JGroups FD_* protocols on the other
> node need to do their work and discover the failure. If you have any
> commands in flight, they might fail. I highly encourage you to use a larger
> cluster (with odd number of nodes if possible). Having only two nodes can
> be a bit dangerous. Imagine a partition split, after the split heals, which
> node is right? Hard to tell...
>
>
>>
>> I would say that this is expected as the node is down. However, it should
>> not be a problem for the whole system.
>>
>> My replication settings are the following:
>>
>>> <distributed-cache name="sessions" mode="SYNC" owners="2"/>
>>> <distributed-cache name="authenticationSessions" mode="SYNC" owners="2"/>
>>> <distributed-cache name="offlineSessions" mode="SYNC" owners="2"/>
>>> <distributed-cache name="clientSessions" mode="SYNC" owners="2"/>
>>> <distributed-cache name="offlineClientSessions" mode="SYNC" owners="2"/>
>>> <distributed-cache name="loginFailures" mode="SYNC" owners="2"/>
>>>
>>
>> Do I need to change something else?
>>
> Here's the exactly the same problem. With number of owners=2 and 2 nodes,
> this is essentially a replicated cache (despite some differences in logic).
> I'd advice using at least 3 nodes (or even better 5).
>
>>
>> On Wed, Aug 29, 2018 at 9:51 AM, Rafael Weingärtner <
>> rafaelweingartner at gmail.com> wrote:
>>
>>> Ah no problem. It was my fault. I forgot to start debugging from the
>>> ground up  (connectivity, firewalls, applications and so on )
>>>
>>> On Wed, Aug 29, 2018 at 9:49 AM, Bela Ban <bban at redhat.com> wrote:
>>>
>>>> Excellent! Unfortunately, JGroups cannot detect this...
>>>>
>>>> On 29/08/18 14:42, Rafael Weingärtner wrote:
>>>>
>>>>> Thanks!
>>>>> The problem was caused by firewalld blocking Multicast traffic.
>>>>>
>>>>> On Fri, Aug 24, 2018 at 7:28 AM, Sebastian Laskawiec <
>>>>> slaskawi at redhat.com <mailto:slaskawi at redhat.com>> wrote:
>>>>>
>>>>>     Great write-up! Bookmarked!
>>>>>
>>>>>     On Thu, Aug 23, 2018 at 4:36 PM Bela Ban <bban at redhat.com
>>>>>     <mailto:bban at redhat.com>> wrote:
>>>>>
>>>>>         Have you checked
>>>>>         https://github.com/belaban/workshop/blob/master/slides/
>>>>> admin.adoc#problem-1-members-don-t-find-each-other
>>>>>         <https://github.com/belaban/workshop/blob/master/slides/
>>>>> admin.adoc#problem-1-members-don-t-find-each-other>?
>>>>>
>>>>>         On 23/08/18 13:53, Sebastian Laskawiec wrote:
>>>>>          > +Bela Ban <mailto:bban at redhat.com <mailto:bban at redhat.com>>
>>>>>          >
>>>>>          > As I expected, the cluster doesn't form.
>>>>>          >
>>>>>          > I'm not sure where and why those UDP discovery packets are
>>>>>         rejected. I
>>>>>          > just stumbled upon this thread [1], which you may find
>>>>>         useful. Maybe
>>>>>          > Bela will also have an idea what's going on there.
>>>>>          >
>>>>>          > If you won't manage to get UDP working, you can always fall
>>>>>         back into
>>>>>          > TCP (and MPING).
>>>>>          >
>>>>>          > [1]
>>>>>         https://serverfault.com/questions/211482/tools-to-
>>>>> test-multicast-routing
>>>>>         <https://serverfault.com/questions/211482/tools-to-
>>>>> test-multicast-routing>
>>>>>          >
>>>>>          > On Thu, Aug 23, 2018 at 1:26 PM Rafael Weingärtner
>>>>>          > <rafaelweingartner at gmail.com
>>>>>         <mailto:rafaelweingartner at gmail.com>
>>>>>         <mailto:rafaelweingartner at gmail.com
>>>>>
>>>>>         <mailto:rafaelweingartner at gmail.com>>> wrote:
>>>>>          >
>>>>>          >     Thanks for the reply Sebastian!
>>>>>          >
>>>>>          >
>>>>>          >         Note, that IP Multicasting is disabled in many data
>>>>>         centers (I
>>>>>          >         have never found out why they do it, but I've seen
>>>>> it
>>>>>         many, many
>>>>>          >         times). So make sure your cluster forms correctly
>>>>>         (just grep
>>>>>          >         logs and look for "view").
>>>>>          >
>>>>>          >
>>>>>          >     I thought about that. Then, I used tcpdump, and I can
>>>>> see the
>>>>>          >     multicast packets from both Keycloak replicas. However,
>>>>>         it seems
>>>>>          >     that these packets are being ignored.
>>>>>          >
>>>>>          >         root at Keycloak01:/# tcpdump -i eth0 port 7600 or
>>>>> port
>>>>>         55200 or
>>>>>          >         port 45700 or port 45688 or port 23364 or port 4712
>>>>>         or port 4713
>>>>>          >         tcpdump: verbose output suppressed, use -v or -vv
>>>>> for
>>>>>         full
>>>>>          >         protocol decode
>>>>>          >         listening on eth0, link-type EN10MB (Ethernet),
>>>>>         capture size
>>>>>          >         262144 bytes
>>>>>          >         11:13:36.540080 IP keycloak02.local.55200 >
>>>>>         230.0.0.4.45688:
>>>>>          >         UDP, length 83
>>>>>          >         11:13:41.288449 IP keycloak02.local.55200 >
>>>>>         230.0.0.4.45688:
>>>>>          >         UDP, length 83
>>>>>          >         11:13:46.342606 IP keycloak02.local.55200 >
>>>>>         230.0.0.4.45688:
>>>>>          >         UDP, length 83
>>>>>          >
>>>>>          >
>>>>>          >         root at keycloak02:/# tcpdump -i eth0 port 7600 or
>>>>> port
>>>>>         55200 or
>>>>>          >         port 45700 or port 45688 or port 23364 or port 4712
>>>>>         or port 4713
>>>>>          >         tcpdump: verbose output suppressed, use -v or -vv
>>>>> for
>>>>>         full
>>>>>          >         protocol decode
>>>>>          >         listening on eth0, link-type EN10MB (Ethernet),
>>>>>         capture size
>>>>>          >         262144 bytes
>>>>>          >         11:12:14.218317 IP Keycloak01.local.55200 >
>>>>>         230.0.0.4.45688:
>>>>>          >         UDP, length 83
>>>>>          >         11:12:23.146798 IP Keycloak01.local.55200 >
>>>>>         230.0.0.4.45688:
>>>>>          >         UDP, length 83
>>>>>          >         11:12:27.201888 IP Keycloak01.local.55200 >
>>>>>         230.0.0.4.45688:
>>>>>          >         UDP, length 83
>>>>>          >
>>>>>          >
>>>>>          >
>>>>>          >     Here go the log entries. I filtered by “view”. This is
>>>>>         from Keycloak01.
>>>>>          >
>>>>>          >         ^[[0m^[[0m11:16:57,896 INFO
>>>>>          >                   [org.infinispan.remoting.
>>>>> transport.jgroups.JGroupsTransport]
>>>>>          >         (MSC service thread 1-4) ISPN000094: Received new
>>>>>         cluster view
>>>>>          >         for channel ejb: [keycloak01|0] (1) [keycloak01]
>>>>>          >         ^[[0m^[[0m11:16:57,896 INFO
>>>>>          >                   [org.infinispan.remoting.
>>>>> transport.jgroups.JGroupsTransport]
>>>>>          >         (MSC service thread 1-2) ISPN000094: Received new
>>>>>         cluster view
>>>>>          >         for channel ejb: [keycloak01|0] (1) [keycloak01]
>>>>>          >         ^[[0m^[[0m11:16:57,897 INFO
>>>>>          >                   [org.infinispan.remoting.
>>>>> transport.jgroups.JGroupsTransport]
>>>>>          >         (MSC service thread 1-1) ISPN000094: Received new
>>>>>         cluster view
>>>>>          >         for channel ejb: [keycloak01|0] (1) [keycloak01]
>>>>>          >         ^[[0m^[[0m11:16:57,898 INFO
>>>>>          >                   [org.infinispan.remoting.
>>>>> transport.jgroups.JGroupsTransport]
>>>>>          >         (MSC service thread 1-3) ISPN000094: Received new
>>>>>         cluster view
>>>>>          >         for channel ejb: [keycloak01|0] (1) [keycloak01]
>>>>>          >         ^[[0m^[[0m11:16:57,962 INFO
>>>>>          >                   [org.infinispan.remoting.
>>>>> transport.jgroups.JGroupsTransport]
>>>>>          >         (MSC service thread 1-1) ISPN000094: Received new
>>>>>         cluster view
>>>>>          >         for channel ejb: [keycloak01|0] (1) [keycloak01]
>>>>>          >
>>>>>          >
>>>>>          >     I expected it to be only one.  I mean, I first started
>>>>>         Keycloak01,
>>>>>          >     and just then Keycloak02. Next, we have the logs from
>>>>>         Keycloak02.
>>>>>          >
>>>>>          >         ^[[0m^[[0m11:17:34,950 INFO
>>>>>          >                   [org.infinispan.remoting.
>>>>> transport.jgroups.JGroupsTransport]
>>>>>          >         (MSC service thread 1-3) ISPN000094: Received new
>>>>>         cluster view
>>>>>          >         for channel ejb: [keycloak02|0] (1) [keycloak02]
>>>>>          >         ^[[0m^[[0m11:17:34,952 INFO
>>>>>          >                   [org.infinispan.remoting.
>>>>> transport.jgroups.JGroupsTransport]
>>>>>          >         (MSC service thread 1-4) ISPN000094: Received new
>>>>>         cluster view
>>>>>          >         for channel ejb: [keycloak02|0] (1) [keycloak02]
>>>>>          >         ^[[0m^[[0m11:17:34,957 INFO
>>>>>          >                   [org.infinispan.remoting.
>>>>> transport.jgroups.JGroupsTransport]
>>>>>          >         (MSC service thread 1-1) ISPN000094: Received new
>>>>>         cluster view
>>>>>          >         for channel ejb: [keycloak02|0] (1) [keycloak02]
>>>>>          >         ^[[0m^[[0m11:17:34,957 INFO
>>>>>          >                   [org.infinispan.remoting.
>>>>> transport.jgroups.JGroupsTransport]
>>>>>          >         (MSC service thread 1-2) ISPN000094: Received new
>>>>>         cluster view
>>>>>          >         for channel ejb: [keycloak02|0] (1) [keycloak02]
>>>>>          >         ^[[0m^[[0m11:17:35,052 INFO
>>>>>          >                   [org.infinispan.remoting.
>>>>> transport.jgroups.JGroupsTransport]
>>>>>          >         (MSC service thread 1-1) ISPN000094: Received new
>>>>>         cluster view
>>>>>          >         for channel ejb: [keycloak02|0] (1) [keycloak02
>>>>>          >
>>>>>          >
>>>>>          >     They are similar. It seems that both applications are
>>>>> not
>>>>>         seeing
>>>>>          >     each other. At first, I thought that the problem was
>>>>>         caused by
>>>>>          >     “owners=1” configuration (the lack of data
>>>>>         synchronization between
>>>>>          >     replicas). I then changed it to “owners=2”, but still,
>>>>> if
>>>>>         I log in
>>>>>          >     the Keycloak01 and then force my request to go two
>>>>>         Keycloak02, my
>>>>>          >     session is not there, and I am requested to log in
>>>>> again.
>>>>>          >
>>>>>          >     Do you need some other log entries or configuration
>>>>> files?
>>>>>          >
>>>>>          >     Again, thanks for your reply and help!
>>>>>          >
>>>>>          >     On Thu, Aug 23, 2018 at 5:24 AM, Sebastian Laskawiec
>>>>>          >     <slaskawi at redhat.com <mailto:slaskawi at redhat.com>
>>>>>         <mailto:slaskawi at redhat.com <mailto:slaskawi at redhat.com>>>
>>>>> wrote:
>>>>>          >
>>>>>          >
>>>>>          >
>>>>>          >         On Wed, Aug 22, 2018 at 10:24 PM Rafael Weingärtner
>>>>>          >         <rafaelweingartner at gmail.com
>>>>>         <mailto:rafaelweingartner at gmail.com>
>>>>>          >         <mailto:rafaelweingartner at gmail.com
>>>>>
>>>>>         <mailto:rafaelweingartner at gmail.com>>> wrote:
>>>>>          >
>>>>>          >             Hello Keycloakers,
>>>>>          >
>>>>>          >             I have some doubts regarding Keycloak and load
>>>>>         balancers. I
>>>>>          >             set up two
>>>>>          >             keycloak replicas to provide HA. To start them I
>>>>>         am using
>>>>>          >             “./standalone.sh
>>>>>          >             --server-config=standalone-ha.xml”.  I am
>>>>>         assuming that they
>>>>>          >             will use
>>>>>          >             multicast to replicate information between
>>>>> nodes,
>>>>>         right?
>>>>>          >
>>>>>          >
>>>>>          >         That is correct. It uses PING protocol, which in
>>>>> turn
>>>>>         uses IP
>>>>>          >         Multicasting for discovery.
>>>>>          >
>>>>>          >         Note, that IP Multicasting is disabled in many data
>>>>>         centers (I
>>>>>          >         have never found out why they do it, but I've seen
>>>>> it
>>>>>         many, many
>>>>>          >         times). So make sure your cluster forms correctly
>>>>>         (just grep
>>>>>          >         logs and look for "view").
>>>>>          >
>>>>>          >             Then, I set up a load balancer layer using
>>>>> Apache
>>>>>         HTTPD and
>>>>>          >             AJP connector
>>>>>          >             via 8009 port. To make everything work I needed
>>>>>         to use
>>>>>          >             sticky session;
>>>>>          >             otherwise, the login would never happen. I am
>>>>>         fine with the
>>>>>          >             sticky session,
>>>>>          >             however, if I stop one of the replicas where the
>>>>>         user is
>>>>>          >             logged in, when
>>>>>          >             the user access Keycloak again, he/she is asked
>>>>>         to present
>>>>>          >             the credentials
>>>>>          >             as if he/she was not logged in the other
>>>>> Keycloak
>>>>>         replica.
>>>>>          >             Is that the
>>>>>          >             expected behavior?
>>>>>          >
>>>>>          >
>>>>>          >         My intuition tells me that your cluster didn't form
>>>>>         correctly
>>>>>          >         (as I mentioned before, grep the logs and look for
>>>>> "view"
>>>>>          >         generated by JGroups). Therefore, if you enable
>>>>>         sticky session,
>>>>>          >         all your requests get to the same Keycloak instance,
>>>>>         which has
>>>>>          >         everything in the local cache. That's why it works
>>>>> fine.
>>>>>          >
>>>>>          >
>>>>>          >             Is there some troubleshooting or test that I can
>>>>>         perform to
>>>>>          >             check if
>>>>>          >             replication is being executed?
>>>>>          >
>>>>>          >
>>>>>          >         Let's start with investigating the logs. Later on we
>>>>>         can check JMX.
>>>>>          >
>>>>>          >
>>>>>          >             --
>>>>>          >             Rafael Weingärtner
>>>>>          >             _______________________________________________
>>>>>          >             keycloak-user mailing list
>>>>>          > keycloak-user at lists.jboss.org
>>>>>         <mailto:keycloak-user at lists.jboss.org>
>>>>>          >             <mailto:keycloak-user at lists.jboss.org
>>>>>         <mailto:keycloak-user at lists.jboss.org>>
>>>>>          > https://lists.jboss.org/mailman/listinfo/keycloak-user
>>>>>         <https://lists.jboss.org/mailman/listinfo/keycloak-user>
>>>>>          >
>>>>>          >
>>>>>          >
>>>>>          >
>>>>>          >     --
>>>>>          >     Rafael Weingärtner
>>>>>          >
>>>>>
>>>>>         --         Bela Ban | http://www.jgroups.org
>>>>>
>>>>>
>>>>>
>>>>>
>>>>> --
>>>>> Rafael Weingärtner
>>>>>
>>>>
>>>> --
>>>> Bela Ban | http://www.jgroups.org
>>>>
>>>>
>>>
>>>
>>> --
>>> Rafael Weingärtner
>>>
>>
>>
>>
>> --
>> Rafael Weingärtner
>>
>


-- 
Rafael Weingärtner


More information about the keycloak-user mailing list