Consul-esm operational mode for multi instance

Hello, I started kicking the tires with Consul-ESM and it appears that if you start more than 1 esm instance the newly started instances will just be on standby waiting to acquire a lock. Does that mean that there can only be one active Consul ESM instance that performs the health checking of external services at a time? Can there be an instance where you have more than 1 instance? Let’s say if we start up 10 esm instances would it mean that 9 of them are just standby?



You are correct. ESM doesn’t shard monitoring out to the other ESM instances. ESM elects a leader that does all the checks and any other ESM instances, running against the same consul servers, are hot spares.

This is about to get an optional exception when Namespaces (a Consul Enterprise feature) are in use so you can have per-Namespace ESM clusters, but other than that they are strictly for HA/redundancy.

If you have a use case that doesn’t work with this for some reason, please file an issue in github.