Problem with upgrading from 11.0 to 11.1 Without downtime

[Pasquale Gianluca Costa]

Hi,

 

I need to upgrade the patches without downtime, as per the documentation

 

https://techdocs.broadcom.com/us/en/ca-enterprise-software/layer7-api-management/api-gateway/11-0/install-configure-upgrade/configure-a-gateway-cluster/deactivating-a-cluster-node.html

 

where downtime is expected.

 

The infrastructure in question consists of a cluster of 4 machines, 2 with databases and 2 without databases. The two database machines are replicated.

 

How can I proceed?

Thank you

[Gustavo Azolas]

Hi Pasquale :

I do not see a secure way to achieve a Gw upgrade without downtime on this use case , because the ssg replication in place.
- to stop and restart that replication will have a  downtime due need to stop ssg service too.
- Patching Gw requires also a gateway server reboot. 
Will be more secure if do you find a window time to apply the upgrade and in case of replication broken you will be able to re-initialize properly too.

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[Vince Baker]

Hi Pasquale,

Maybe I'm missing something, but why can't this be done the way we've always upgraded a single cluster in the past? i.e. Declustering, or in your case splitting the cluster into just 2 parts. The following would be based on you being able to provide service with 2 out of 4 gateways running. If you don't have enough capacity I'm sure Broadcom will help with temporary upgrade licensing to add more resources for a few hours only.

I'd do the following:

1. Ensure replication is in sync.
2. Break replication
3. check, or if needed, point nodes 1 & 3 to Node 1's DB (call it upg_cluster_1 for this purpose)
4. point nodes 2 & 4 to Node 2's DB ((call it upg_cluster_2 for this purpose)
5. Cut traffic to nodes 2 & 4 using load balancer or iptables (Leaving traffic only going to upg_cluster_1)
6. Do upgrade on upg_cluster_2 
7. Do hidden live tests in upg_cluster_2
8. Enable upg_cluster_2 in load balancer
9. Repeat steps 5 onward for 1 & 3 (upg_cluster_1) 
10. Re-enable replication
11. Point nodes 2 & 4 to Node 1's DB
12. Restart Nodes 2 & 4
13. Put all nodes back in load balance pool.

We'd be happy to help you further in an Expert Services engagement if needed.

Regards

Vince Baker

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