Consul datacenter federation enables operators to extend their Consul environments by connecting multiple HashiCorp Cloud Platform (HCP) Consul clusters together within a region. This process ultimately lowers the operational overhead of connecting applications across distinct regions, as well as enables a more consistent, and improved, security model. With HCP Consul, the server-to-server connectivity is automatically handled by the HCP platform.
To learn how to enable HCP Consul federation, please visit the Federate Multiple HCP Consul clusters tutorial.
- Do not overlap network CIDR blocks for the HashiCorp Virtual Network (HVN) associated with the federated Consul Clusters.
- Consul has the concept of primary and secondary clusters. Any cluster that you intend to designate as secondary must be added through federation. Standalone clusters cannot be added to an existing fedearation.
- By default, the total number of Consul clusters allowed in an HCP Organization is limited up to 6. If you would like to federate additional clusters, please file a support ticket to increase the limit.
- The table below shows the federation options for different HCP Consul Tiers.
|Development (For proof of concept testing only)||Intra and Inter region federation|
|Standard (For production deployments)||Intra region federation|
|Plus (For production deployments)||Intra* and Inter region federation|
*Must be with another Plus tier cluster
Consul uses the gossip protocol to share information across agents. In order for this to function properly, there is a maximum Round Trip Time (RTT) latency for communication between clients and servers.
|Consul client to HCP server agent Round Trip Time (RTT) latency||Mean <= 50ms, and 99 percentile <=100ms|
If you have deployed your Consul server in HCP on AWS, here are some reference links to determine latency between your HCP and workload VPC regions in which Consul client agents are deployed.
We recommend connectivity between Consul clients and HCP Consul servers within the same region to avoid any potential cross region network interruptions.
The following table provides the default number of HashiCorp Virtual Networks and Consul cluster available to HCP users.
|Resource||Development Tier||Standard/Plus Tier|
|Number of Consul Clusters||3||6|
|Number of HVNs||3||3|
If you require additional resources, please contact support.