jbweber2
Enthusiast
Enthusiast

vCO Cluster Mode Questions

I've been playing around with putting vCO into cluster mode to deploy a vCO instance with a DR instance in a secondary site.

From what I can see with the default configuration my options are running both vCO instances as active / active or running an active / passive configuration.

I've got a few different questions I'm hoping people have experience with cluster mode might be able to answer.

In active / passive mode is there a way to say which node you want to have be the active node? From testing it looked like it randomly elected a node to be the active node. Is there a better pattern to use to have a stand by instance of vCO?

In active / active mode is there any kind of health check type endpoint I can use to configure on my load balancer to know whether to pull a node out of rotation?

In active / active mode is there anything special which you need to know with relation to state or context or does it really not matter which instance of vCO you hit to execute / verify running workflows or actions?

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igaydajiev
VMware Employee
VMware Employee

>In active / passive mode is there a way to say which node you want to have be the active node? From testing it looked like it randomly elected a node to be the active node. Is there a better pattern to use to have a stand by instance of vCO?


The first one that boots will start in active mode.

If you have preference you can start first the server that you want to be active first.


>In active / active mode is there any kind of health check type endpoint I can use to configure on my load balancer to know whether to pull a node out of rotation?

You can check following kb arrticle for example configuration of vCO with load balancer.

VMware KB: Setting up Nginx load balancing software with VMware vCenter Orchestrator 5.5



>In active / active mode is there anything special which you need to know with relation to state or context or does it really not matter which instance of vCO you hit to execute / verify running workflows or actions?

All vCO nodes participating in the cluster should have the same configuration and there is no difference on which node the workflow will be executed.


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jbweber2
Enthusiast
Enthusiast

Will the following scenario work since I don't tihnk control of the active node in an active / passive cluster will work for me:

vCO Instance A ---> DB1

In the event of an outage where instance A is no longer available at all, configure a brand new vCO instance to point at DB1. Will that new instance be able to pick up where instance A left off? Basically no HA just a DR solution?

I did a quick test and it looks like it works as I would expect, I just want to make sure there are no subtle gotchas I'm missing in this kind of scenario.

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igaydajiev
VMware Employee
VMware Employee

It should work.

All the state of currently executed workflows is preserved in the DB.

One gotchas is that backup vCO must have the same configuration as the active node.

What this mean is that some of the information in the DB is encrypted (passwords...). Also there are trusted certificates ...

In order to be able backup node to continue from where the first one has stopped it must be configured teh same way

or cloned from the first node.

here is the guide for making both nodes identical : vSphere 5.5 Documentation Center

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