Am 27. Juni 2020 11:29:03 MESZ schrieb Mark Thomas <>:
>On 27/06/2020 10:19, Thomas Meyer wrote:
>> Hi,
>> A few questions regarding tomcat session replication:
>load-balancing and session replication are two separate parts of an
>overall clustering solution.
>> 1) is the jvmRoute attribute on Engine object necessary for session
>replication to work correctly?
>No, but if you don't use it it places a number of restrictions on the
>web application behaviour and on the configuration of session
>The limitations are:
>- you need to use the DeltaManager (which doesn't scale as well as the
>  BackupManager);

Yes, I'm using default DeltaManager as I will only have two pods running Tomcat.

>- any requests made by the client that depend on the session MUST be
>  issued in series, not in parallel; and

Not sure about this one, the app uses spring default security for login. So 
need to check this one.

>- the session Manager must be configured to update all the other nodes
>  in the cluster BEFORE the current request returns to the client.

How to do that? I did have a look at Manager/DeltaManager attributes but didn't 
see something that looks like above setting. Can you plea point me in the right 

>> 2) does session replication only work correctly with sticky load
>balancer routing?
>No. It works quite happily without it.

Good to know.

>> My setup is
>> 1) load balancer without sticky session routing into kubernetes
>> 2) two pods running tomcat with cloud member provider, which see and
>find each other
>> No jvmRoute attribute is set.

Another question regarding jvmRoute:
Even if my load balancer has no sticky sessions, should I add jvmRoute 
attribute? I think I could easily add the pod's name as jvmRoute.

>> Above setup doesn't work and give strange errors for the distributed
>webapp which relies on http sessions.
>> Should above setup work? If not why and what do I need to fix?
>> Any hints of what logging to enable to debug the problem if any at
>Please show us how you have configured the session manager and

My setup is just go with the defaults:

<Cluster className="org.apache.catalina.ha.tcp.SimpleTcpCluster">
<Channel className="">

In the logs I can see the member appears/disappears messages, which is a good 
thing I guess.

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