Package io.helidon.tracing.jersey.client

Class ClientTracingFilter

  • All Implemented Interfaces:
    ClientRequestFilter, ClientResponseFilter
    @Priority(750)
public class ClientTracingFilter
extends Object
implements ClientRequestFilter, ClientResponseFilter
    This filter adds tracing information the the associated JAX-RS client call based on the provided properties.

    In order to inject the tracing information properly, Tracer and an optional parent SpanContext needs to be resolved. In case we are in scope of inbound JAX-RS request, the client also uses inbound HTTP headers to determine correct headers for outbound call.

    The Tracer gets resolved in the following order:

    1. From request property TRACER_PROPERTY_NAME
    2. From JAX-RS server, when the client is invoked in scope of a JAX-RS inbound request and appropriate filter is configured (see helidon-tracing-jersey and helidon-microprofile-tracing modules)
    3. From GlobalTracer.get()

    The parent SpanContext is resolved as follows

    1. From request property CURRENT_SPAN_CONTEXT_PROPERTY_NAME
    2. From JAX-RS server, when the client is invoked in scope of a JAX-rs inbound request

    Inbound HTTP headers are resolved from JAX-RS server.

    For each client call, a new Span with operation name generated from HTTP method and resource method and class is created based on the resolved Tracer and an optional parent Span. The span information is also propagated to the outbound request using HTTP headers injected by tracer.

    Example 1 - client within a JAX-RS resource (with tracing integration configured on server): 

     public String someMethod(@Uri(BACKEND) WebTarget target) {
   Response response = target.request().get();
   // process the response
 }

    Example 2 - standalone client (with access to tracer and span), assuming we have a WebTarget ready as target 

     target.request()
   .property(TracingClientFilter.TRACER_PROPERTY_NAME, tracer)
   .property(TracingClientFilter.CURRENT_SPAN_CONTEXT_PROPERTY_NAME, spanContext)
   .get();

    • Field Detail

      • JAX_RS_TRACING_COMPONENT

        public static final String JAX_RS_TRACING_COMPONENT
        Name of tracing component used to retrieve tracing configuration.
        See Also:
        Constant Field Values

      • SPAN_NAME_PROPERTY_NAME

        public static final String SPAN_NAME_PROPERTY_NAME
        Override name of the span created for client call.

      • ENABLED_PROPERTY_NAME

        public static final String ENABLED_PROPERTY_NAME
        If set to false, tracing will be disabled. If set to true, tracing will depend on overall configuration.

      • X_OT_SPAN_CONTEXT

        public static final String X_OT_SPAN_CONTEXT
        Header used by Envoy proxy. Automatically propagated when within Jersey and when using helidon-microprofile-tracing module.
        See Also:
        Constant Field Values

      • X_REQUEST_ID

        public static final String X_REQUEST_ID
        Header used by routers. Automatically propagated when within Jersey and when using helidon-microprofile-tracing module.
        See Also:
        Constant Field Values

    • Constructor Detail

      • ClientTracingFilter

        public ClientTracingFilter()
        Default constructor so this filter can be registered with Jersey as a class. Required by integrated platform.