CAPI vs Pattern based discovery for Azure

[varunkumar11863]

Hi all, technically what is the difference between CAPI based and Pattern based discovery? As per my understanding, Pattern based discovery used ECC Queue and worker threads for processing the input received. Is this the same for CAPI based, or does CAPI uses REST calls to cloud provider? I have heard from my team that there was node exhaustion in past when they used CAPI based, so I am assuming it was about API_INT node.

If anyone has looked into it, will be really helpful.

[Ram Devanathan1]

CAPI based cloud discovery is legacy - that's all. going forward (and already the case) pattern based discovery is the way to go. both use API, anyhow

[varunkumar11863]

Hi @Ram Devanathan1  

Thanks for replying. Though we have implemented the Pattern based discovery, we are exploring if it can lead to performance degradation. My old team used CAPI based discovery and as per their comments, they mentioned they faced performance degradation / nodes exhaustion. They are not around anymore; hence I cannot check further with them.

Do you know if CAPI based was processing the inbound message using API_INT semaphores or via worker threads? Trying to understand the impact on the system. We have MID Servers available (CPU / Memory), so probing is not an issue, but can flux of inbound response sensors cause delay in worker threads eventually causing performance issues? Is Pattern based better than CAPI on performance point of view?

[Ram Devanathan1]

CAPI discovery code we don't maintain any more - customers have been moving to Patterns. I would suggest let's not go down the rat-hole digging more details on CAPI discovery.

[varunkumar11863]

Hi @Ram Devanathan1 , Ok.

For Pattern based discovery, could you please confirm if my understanding correct;

"API_INT semaphores would be used only when ecc_queue record input insert happens (should be in milliseconds). Only thing we need to manage from ServiceNow instance is if jobs are getting processed fast. If yes, then there should not be any performance issues"