High availability deployment of Customer Checkout Manager

[stefan_baust]

Hello,

is there any advice / documentation around deploying Customer Checkout Manager in a High Availability "cluster" / multiple Tomcat servers? I assume if this is done one can only have one "leading" CCOm executing scheduled jobs for example, also db-upgrades might be difficult to do without a downtime.

Is there a list / tips to consider when trying to do this?

[JoergAldinger]

Hello stefan.baust ,

This is an interesting topic indeed. I haven't seen any official documentation about it, yet.

However, here are a few ideas:

• HANA DB can be easily installed in high availability. Lots of documentation is available to do this, including some specific documentation for Business One: SAP Business One, version for SAP HANA
• We have also made a satisfying experience using Azure SQL as backend database for CCOM, which has considerable a SLA.
• We haven't had any major reliability issues with shared (multi-version and multi-tenant) CCOM installations. In fact, it is quite easy to do. We generally install one Tomcat instance per major CCO Feature Pack. Then, to upgrade one tenant we just:

1. Unregister the tenant on the original Tomcat instance
2. Take a quick schema export (just in case)
3. Register the tenant on the destination Tomcat instance/version
4. Wait for the tenant upgrade to complete
5. Update the destination in the reverse proxy we set up to be able to seamlessly redirect each tenant's traffic, no matter which host or Tomcat instance is serving up CCOM behind the curtains.

I don't *think* you can safely run two tomcat instances connected to the same tenant. That would be something that would have to be carefully taken care of by the CCO team to avoid any concurrency issues. Maybe bikash.bansal can give his opinion on that topic...

Hope this helps.

Best regards,

Joerg.

[Foivos]

Check here: https://help.sap.com/docs/SAP_CUSTOMER_CHECKOUT/8f711df7d2aa4f1aa29f88c86cef2081/09937f9882ac490fb05...

And also here: https://help.sap.com/docs/SAP_CUSTOMER_CHECKOUT?locale=en-US (main product page).

I could not find much around high availability / clustering...

As for a DB upgrade without downtime, this can be done with HANA DB if you have a Disaster Recovery setup in place (Primary HANA DB replicating to a secondary HANA DB). You can upgrade the secondary first while your primary is up and running (replication will be interrupted to do this), then set up the replication again, replicate from Primary to Secondary (you can do this from lower db version to higher but not vice versa), then switch over to Secondary as your new upgraded Primary DB, break replication, upgrade former Primary, reset replication, switch back over to original primary.

System downtime is very minimal (few minutes to switch over when needed) with a short period where you don't really have a secondary system available if needed.

Edit: This blog does not talk about high availability, but rather about installing more CCMs on one machine, but it may give you some hints to what you need and the author may be able to help you with info on High Availability setups.

https://blogs.sap.com/2018/07/17/install-multiple-sap-customer-checkout-manager-in-same-machine/