topic Re: Setting up Second cluster AG for HA purposes in Open Q&A

Setting up second cluster ActiveGate for HA purposes

runatyr — Thu, 07 Mar 2024 09:00:04 GMT

Hello:

We have a set of DMZ servers with an environment ActiveGate.

That Environment ActiveGate communicates with the Cluster ActiveGate as designed.

The issue is that when the Environment ActiveGate or Cluster ActiveGate is patched/rebooted this causes a temporary loss of communication which can false positives on some alerts we have created.

The proposed solution is to place a second server to act as a Cluster ActiveGate as well.

Is it possible to have 2 cluster ActiveGates now? As I understand this was a limitation years ago for a managed cluster.

If it is not possible, an alternative would be to manually allow the Environment ActiveGate to communicate inbound to the managed cluster directly (bypassing the Cluster ActiveGate when it is being patched/unavailable). If this were to be allowed, what port would the Environment ActiveGate attempt to talk to the Managed Cluster when the Cluster ActiveGate is unavailable?

Re: Setting up Second cluster AG for HA purposes

ChadTurner — Fri, 16 Feb 2024 19:46:30 GMT

interesting ask, would be a great enhancement to network zones at the cluster level for Managed customers. I've run into issues where the system only allowed 1 so we leveraged a host alias and had two hosts with the same alias so as one was spun down, it leveraged the alias that kicked us over to the other host that was running and supporting the traffic. just an idea worth checking out.

Last resort would be to toss in a MW when you have your planned upgrade.

Re: Setting up Second cluster AG for HA purposes

PacoPorro — Mon, 19 Feb 2024 08:58:01 GMT

Of course, you can add a second Cluster Activegate to a Managed Cluster, even more, I recommend it.
As you can see in the schema from the link, there's a reference about "Cluster Activegates", plural.

https://docs.dynatrace.com/managed/shortlink/managed-deployment-scenarios#scenario-3-integration-with-existing-it-landscape

Keep in mind you will need a load balancer in front of the cAGs, and then you can configure it in Dynatrace

https://docs.dynatrace.com/managed/shortlink/managed-ssl-cluster-ag#configure-dynatrace-to-manage-the-domain-and-certificate-for-cluster-activegate

Re: Setting up Second cluster AG for HA purposes

runatyr — Wed, 21 Feb 2024 14:42:11 GMT

What about not using a Load balancer in front of 2 Cluster AG's ? Could I 'essentially' load blanace and set half the agents to report to Cluster AG #1 as first server to contact, and Cluster AG #2 as the second server to contact? And then list the opposite server as the second point of contact for each set>?

Re: Setting up Second cluster AG for HA purposes

PacoPorro — Wed, 21 Feb 2024 15:30:25 GMT

All agents are informed about the available endpoints. You can verify this by using the oneagentctl --get-server command on any of the agents. If you wish to manage how the agents connect to a specific cluster activegate, you should utilize network zones. By enforcing connectivity from a particular environment activegate to a single cluster activegate (at the network level, not within Dynatrace), you can achieve this control. However, it’s important to note that if your cluster activegate experiences an outage, the environment activegate reporting to that cluster won’t be able to establish communication with the cluster

So I highly recommend a LoadBalancer.