Let's take an example of a request from an IIoT device that goes through multiple services, as seen in the following diagram:
Requests from the device go to multiple services
Each service logs the name of the service logs, but this is not enough information to trace the log back to the request, so it is ideal to generate a correlation ID and pass it between the services using HTTP headers. Each service should look up the HTTP header and log it as part of the log format in such a way that we can then trace the request all the way to the end of the session. This is illustrated in the following diagram:
Logs with ...
