Is Consul Agent to Agent communication required?

Consul
1

We are looking at deploying an agent connection to a current consul datacenter where the agent will not have a connection to the other agents. Will this be an issue?

Existing:
DC1 -

  • Consul Servers
  • Consul Agents that are able to talk to each other and the servers

New:
DC1 Extended -

  • Connects to existing Consul Servers
  • No connectivity to existing Consul Agents
2

Yes, it will - agents are expected to have full mesh connectivity to each other, as they all gossip with each other as a means of distributed health checks.

There is a network segments feature in Consul Enterprise but I have never used it so don’t have any experience to share.

3

Thanks @maxb for the response.

Thats a bit unfortunate. So would it be better to create a new DC?

Existing:
DC1 + Agents

New:
DC1a + Agents

DC1 <-> DC1a communications

DC1 Agents do not need to talk to DC1a Agents.

That look correct?

4

That looks like a reasonable approach.

You will need to bear in mind that:

  • A collection of Consul DCs needs one of them statically configured as primary
  • The service catalog is specific to each DC - you need to use queries to potentially resolve services across DCs
  • The KV store is specific to each DC
5

Thanks!

This information was very useful and thank you for your help.