Reads a correlation id from a request header (or generates one if absent), writes it back into that header and adds it to the SLF4J MDC logging context so it appears in every log line of the request. The MDC entry is removed again on the response (and on abort).

See tutorials/operation/10-Correlation-Id.yaml.

Example Configuration

api:
   port: 2000
   flow:
     - correlationId:
         header: X-Trace-Id
         default: "req-${T(java.util.UUID).randomUUID()}"
     - log:
         message: "Correlation id: ${request.header['X-Trace-Id']}"

api:
   port: 2000
   flow:
     - correlationId:
         header: X-Trace-Id
         default: "req-${T(java.util.UUID).randomUUID()}"
     - log:
         message: "Correlation id: ${request.header['X-Trace-Id']}"

Syntax

correlationId:
  '$ref': <string>
  default: <string>
  header: <string>
  language: groovy
  logField: <string>
  xmlConfig: {}

correlationId:
  '$ref': <string>
  default: <string>
  header: <string>
  language: groovy
  logField: <string>
  xmlConfig: {}

Attributes

Name	Required	Default	Description	Examples
$ref	false	-	Reference a component defined under components.	-
default	false	-	Expression used to generate a new correlation id when the header is absent. If omitted, a random UUID is generated.	-
header	false	X-Correlation-Id	Name of the HTTP request header that carries the correlation id.	-
language	false	SpEL	Scripting language used to evaluate the value expression.	SpEL \| groovy \| jsonpath \| xpath
logField	false	correlationId	Name of the MDC variable the correlation id is stored under for logging.	-

Child Structure

Element	Cardinality	Description
xmlConfig	0..1	XML namespace declarations for XPath expressions in the value.

Can be used in

abort api case chain components for global if interceptor internal operationSettings otherwise proxy registration request response serviceProxy soapProxy stompProxy time transport wsStompReassembler