Correlation ID Generator functionality limitation in RTF and CloudHub 2.0

ISSUE

Correlation ID Generator functionality introduced from the Mule 4.4 runtime version onwards to customize the correlation Id does not work as expected in RTF and CloudHub 2.0 environments.

CAUSE

In RTF and CloudHub 2.0 environments, incoming requests flow through the ingress layer and the ingress component generates a correlation Id if the correlation Id header is not found as part of the incoming request. When the mule runtime engine receives the requests, the Correlation ID Generator functionality generates a correlation Id only when the correlation Id header is not received as an incoming header. If there is a correlation Id in the incoming headers, the runtime engine uses the incoming correlation Id and does not generate new value.

The limitation in RTF and CloudHub 2.0 is that even though the client does not send correlation Id, since ingress is generating a correlation Id and injecting into headers, Correlation ID Generator does not generate new values as expected.

SOLUTION

The alternative solution is to wrap all the components after the source scope with 'With CorrelationID Scope' to customize the correlation Id. 

Reference: 

Mule Runtime Correlation ID