We are working on setting up Execution servers for CARA HA architecture. After preliminary research, we have shortlisted 2 methodologies which can best suit our architecture. However we need to understand the pros and cons of both these before we proceed. Please let us know the answers to the below:
Please download and review the CA Release Automation Architecture and Implementation Guide 5.5 - 6.x at the following link:
CA Release Automation 5.x / 6.x Architecture and Implementation Best Practice Guide
You can setup super nodes for a ring configuration, if you are going thru this step, why not setup a STAR configuration? That will give you more flexibility for future expansion if needed.
Now to setup the super node, please follow the instructions in the guide listed at the beginning of this response and review page 24, which explains what you have to do.
So each of the super nodes will contain just two RA agents each? If you create super nodes across data centers, you need to keep in mind the network latency. The description of the make up of the super nodes is very good and again based on the architecture that you decide to use, it will work on both.
Based on the information provided in the above guide, you can find additional information about how the artifacts are distributed to the NES. Release Automation KB: Artifact Distribution and Cleanup
Artifact NES Distribution
Based on the information above, if you setup a super NES, the artifacts will be distributed to the NES servers that make up that super node.
Let me know, if you need any additional information about this.
The ring architecture is the best option in this scenario, a star architecture should only be used when there are a very large number of execution servers. I would recommend that you create supernoded nes's in each data Center and the agents should not be connected across datacenters. I.e all agents in Datacenter x connected to the nes's X1 and X2.
As walter mentioned a lot of these architectures are explained further in the architecture guide,
Hi guewa01/ Keith-Puzey-CA
We have some follow up questions for you . Your answers did help us in our decision. But before proceeding we would like the below questions to be answered:
1 We would not normally recommend adding more execution servers to the ring architecture, as your network grows one of the other architectures may be more practical.
2 If a whole datacenter goes dark the execution servers in the remaining data center will still function but the agents in the offline data center will not be accessible
3 The groups in the studio are purely for administration purposes and and have no impact on the artifact distribution.
4 Can you say which version of RA you are using this affects the scaling numbers,
5 I will confirm with engineering on this point.
If you would like to arrange for a webex to discuss these point please email me so we can arrange this , firstname.lastname@example.org
Based on what Keith mentioned and your future plans. I would recommend that you setup a STAR configuration out of the box just to be on the safe side.
If I understand correctly, you have RA 5.5.2 installed right? Any additional patches installed?
About the 3-DNS, are you referring to the F5 Networks 3-DNS box? Based on what I have been finding, the use of that load balancer should not be a problem.
Yes I am referring to the F5 networks 3 DNS box.