I have already used SOAP, but have never worked with SOA, ESB, or other enterprise application integration schemes. And I find the ESB documentation quite confusing.
There is something that I am not sure of understanding with ESB. I know that this is more of a concept that describes the enterprise network as a bus, and not a specific thing, but still.
I understand that the ESB provides protocol and message translation with legacy services, allows for orchestration, and that the message assignment logic is performed by the ESB. But I also thought of ESB as middleware between different ESB servers (and not just web service interfaces).
If I take the ServiceMix example, I thought it would be natural to have several ServiceMix platforms on different servers that communicate via a common bus / protocol (NMR? JMS?). Therefore, my ServiceMix (a) service created using CAMEL (for example, using some web services) can use the ServiceMix (b) service also created using CAMEL.
Therefore, if my service needs another service, I would just mention its identifier, and the ESB forwarded my request to the correct ServiceMix platform.
But when I read about ServiceMix examples, it seems to me that ServiceMix is previously used as a standalone application server. Not a server cluster.
Is the ESB just an advanced application server? (allow the integration capabilities that it provides)
ESB SOA? ESB? , ESB (a), , SOAP, ESB (b) ?