Service Objects and EMS Client URLs
The service object exposes the EMS server listen port (both inside and outside the cluster).
The service defined in tibemsd-template.yaml is of type NodePort, which means that the corresponding port number will be accessible through all nodes of the cluster.
For example, if your cluster runs on three nodes called node1, node2 and node3 that can be addressed by those host names. If you have exposed your EMS server through a service using port number 8222, EMS clients running outside the cluster will be able to access it either through the tcp://node1:8222, tcp://node2:8222 or tcp://node3:8222 URL, regardless of the node where the container is actually running. This works by virtue of each node proxying port 8222 into the service.
EMS clients running inside the cluster will be able to access the EMS server either in the fashion described above or through its service name. Assuming the service name is emsdev01 and the port still is 8222, that amounts to using the tcp://emsdev01:8222 URL.
To ensure EMS client automated fault-tolerance failover, these must connect with FT double URLs. Using the example above: tcp://node1:8222, tcp://node1:8222 from outside the cluster or tcp://emsdev01:8222, tcp://emsdev01:8222 from inside the cluster. For the first form, since all nodes will proxy port 8222 into the service, repeating the same node name twice fits our purpose. The connection factories in the sample EMS server configuration generated by default upon creating a container illustrate that pattern. Should the EMS server or its container fail, clients will automatically reconnect to the same URL once the server has been restarted.
You can use types of service other than NodePort if they fit your requirements.