How to configure Tomcat session persistence in SAP Business Objects 4.3 on AWS EC2?

Question

I have a two-node cluster running SAP Business Objects 4.3 on AWS EC2. I have an Aurora database backend to hold the metadata, that appears to be properly connected.

Following the documentation on Tomcat 9 , I have tried to implement what they have suggested is the "simplest" cluster configuration :

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

Adding (or rather uncommenting that line) in the server.xml file located in this directory: /opt/bo/sap_bobj/tomcat/conf

Likewise, the instructions indicate to add the line:

<distributable/>

To the appropriate place in /opt/bo/sap_bobj/enterprise_xi40/warfiles/webapps/BOE/WEB-INF/web.xml.

Stopping and restarting Tomcat yields a clean catalina.out file and a successful startup, but sessions don't seem to persist.

Is there any more to the setup for session persistence across nodes?

EDIT: If one of my Tomcat servers is down but I can still access the SAP portal, does that qualify as a successful configuration?

Answer 1

For BusinesssObjects, there is an additional jar that needs to be installed in order for full session persistence to work. See This SAP Note with instructions. There is also a blog post with more detail (it's written for Azure but much of the Tomcat-specific info is the same).

I tried this once and couldn't get it to work, but you may have better luck.

Regarding " If one of my Tomcat servers is down but I can still access the SAP portal, does that qualify as a successful configuration? ". That means that your load balancer is properly detecting a failed server and redirecting traffic to a remaining healthy server. If this is good enough for you, then you don't need any special Tomcat configuration. Just have two (or more) behind the load balancer. Session persistence will get you fault tolerance:

1. You log in to BO
2. The Tomcat server that you connect to crashes
3. You do something else in BO (go to another folder, refresh a report, etc.)
4. Your session continues. You aren't even aware that the server crashed.

Without session persistence (ie, just two Tomcats behind an LB) you get high availability:

1. You log in to BO
2. The Tomcat server that you connect to crashes
3. You do something else in BO (go to another folder, refresh a report, etc.)
4. You are brought back to the BO logon page. Your original session is gone.