Hearbeat on a two-node cluster on a different subnet than on a DR site

Question

Hi,

since Windows 2012 we know that it is not necessary to use a heartbeat NIC in a cluster as far as I can remember.

In my case I have two nodes in a subnet and another node that will be on an external site (Azure) that will be a DR.

1 - Do I need to use a NIC for heartbeat between nodes 1 and 2?
2 - Is there a need for DR sites as well? If so, how would that be possible since they are different networks?

Thank you.

Answer 1

since Windows 2012 we know that it is not necessary to use a heartbeat NIC in a cluster as far as I can remember.

No actually it is from Windows Server 2008 that Heartbeat is not mandatory.

Do I need to use a NIC for heartbeat between nodes 1 and 2?

Not necessarily your WSFC will just work fine if you do not have Heartbeat NIC or heartbeat Configured. I answered a very similar question on Stackexchange before, have a look. But if your NIC which hosts both cluster and client communication gets saturated more often I would suggest you set up heartbeat. It does not adds complexity.

Is there a need for DR sites as well? If so, how would that be possible since they are different networks?

Again depends but configuring that is not a pain, you need to add a network adapter on DR and add a connection. Your network team can easily set it up for you.

Answer 2

Hi,

A dedicated heartbeat network between cluster nodes can make the cluster more stable. Since Cluster nodes send heartbeat packets between each other every interval, if the heartbeat packet is lost due to network issue, the cluster node will be removed the active membership from the cluster. If we only have one cluster network for all kind of cluster traffic, heartbeat packet will have risk to lost when there's heavy network traffic.

In your case, I would suggest you set the heartbeat network on the Primary site nodes, so the Primary site will more stable.

---1 - Do I need to use a NIC for heartbeat between nodes 1 and 2?

Yes, it's recommended to do so.

---2 - Is there a need for DR sites as well? If so, how would that be possible since they are different networks?

DR site is not necessary, but if you want to add a heartbeat network too, you may add an NIC on the DR node, ensure the NIC has network connection with the Heartbeat NICs on the Primary Site, when the network show up in the cluster network, set it as "Allow cluster network communication on this network. Clear the Allow clients to connect through this network check box.

https://ramprasadtech.com/network-recommendations-for-a-hyper-v-cluster-in-windows-server/

Please note: Information posted in the given link is hosted by a third party. Microsoft does not guarantee the accuracy and effectiveness of information.

Thanks for your time!
Best Regards,
Anne

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Answer 3

@Shashank Singh

My words are "A dedicated heartbeat network between cluster nodes can make the cluster more stable. Since Cluster nodes send heartbeat packets between each other every interval, if the heartbeat packet is lost due to network issues, the cluster node will be removed from the active membership from the cluster. If we only have one cluster network for all kind of cluster traffic, heartbeat packet will have a risk to lost when there's heavy network traffic."

I mean "heartbeat packets" "heartbeat packets" "heartbeat packets", not "heartbeat NIC goes down" as you said. Heartbeat packets can send both on cluster network set as "Cluster and client" and "Cluster only". I mean if the customer cluster only has one cluster network set as "Cluster and client", if the cluster network has a heavy load, heartbeat packets on the network have a risk to lose, if the heartbeat packets lost between the nodes reach to dedicated times, the cluster nodes will be removed from the cluster.

So, I suggest the customer set an additional dedicated heartbeat cluster set as "Cluster only", so that heartbeat can send on both on "Cluster only" and "Cluster and client".

Besides, I think my reply and your response are one idea, which means set an additional dedicated heartbeat cluster network is recommended not to mandatory.

However, maybe you have some misunderstanding about my reply.

Anyway, the customer gets what he want.