Preparing the cluster for High Availability:
Review the table to understand the requirements for enabling the High Availability.
- This process has been tested with a minimum of five ECS hosts. However, Cloudera recommends six or more hosts.
- DNS requirements for ECS High Availability must be fulfilled.
| Hostname | Subdomain | Expected Roles | DNS ForwardZone | Reverse Zone PTR |
|---|---|---|---|---|
| “Wildcard” (hostname = *) | apps.ecs.example.com The string “apps” is required, “ecs” is up to user | Virtual app domain wildcard | “A Record” wildcard (hostname = *), may be a CNAME on certain DNS systems that use text-based config. Resolves to fixed IP of ha_proxy (or VIP of some commerical LB’s) | N |
| “apps alias” | apps.ecs.example.com | Virtual app domain alias | “CNAME” alias points to A Record of ha_proxy (or VIP). Alternatively, this can be an ARecord with IP of ha_proxy (or VIP) | N/A |
| HAProxy (or commercial LB) | <domain of your LB> | HA Load Balancer | Depends on vendor/software | |
| ecs-master1 | example.com | ECS Server 1 Docker server | “A Record” resolves to IP of ecs-master1 | Y |
| ecs-master2 | example.com | ECS Server 2 Docker server | “A Record” resolves to IP of ecs-master2 | Y |
| ecs-master3 | example.com | ECS Server 3 Docker server | “ARecord” resolves to IP of ecs-master3 | Y |
| ecs-agentN | example.com | ECS Agent N Docker server N | “ARecord” resolves to IP of ecs-agentN | Y |
