Preparing the cluster for High Availability:

Review the table to understand the requirements for enabling the High Availability.

  1. This process has been tested with a minimum of five ECS hosts. However, Cloudera recommends six or more hosts.
  2. DNS requirements for ECS High Availability must be fulfilled.
Hostname Subdomain Expected Roles DNS ForwardZone Reverse Zone PTR
“Wildcard” (hostname = *) 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” 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 ECS Server 1 Docker server “A Record” resolves to IP of ecs-master1 Y
ecs-master2 ECS Server 2 Docker server “A Record” resolves to IP of ecs-master2 Y
ecs-master3 ECS Server 3 Docker server “A Record” resolves to IP of ecs-master3 Y
ecs-agentN ECS Agent N Docker server N “A Record” resolves to IP of ecs-agentN Y