Package brave.http

Class HttpServerHandler<Req,Resp>

java.lang.Object

brave.http.HttpServerHandler<Req,Resp>

Type Parameters:

Req - the native http request type of the server.

Resp - the native http response type of the server.

public final class HttpServerHandler<Req,Resp>
extends Object

This standardizes a way to instrument http servers, particularly in a way that encourages use of portable customizations via HttpServerParser.

This is an example of synchronous instrumentation:

 Span span = handler.handleReceive(extractor, request);
 Throwable error = null;
 try (Tracer.SpanInScope ws = tracer.withSpanInScope(span)) {
   // any downstream code can see Tracer.currentSpan() or use Tracer.currentSpanCustomizer()
   response = invoke(request);
 } catch (RuntimeException | Error e) {
   error = e;
   throw e;
 } finally {
   handler.handleSend(response, error, span);
 }
 

Method Summary

Modifier and Type	Method	Description
static <Req,Resp> HttpServerHandler<Req,Resp>	create(HttpTracing httpTracing, HttpServerAdapter<Req,Resp> adapter)
<C> brave.Span	handleReceive(brave.propagation.TraceContext.Extractor<C> extractor, C carrier, Req request)	Like handleReceive(TraceContext.Extractor, Object), except for when the carrier of trace data is not the same as the request.
brave.Span	handleReceive(brave.propagation.TraceContext.Extractor<Req> extractor, Req request)	Conditionally joins a span, or starts a new trace, depending on if a trace context was extracted from the request.
void	handleSend(Resp response, Throwable error, brave.Span span)	Finishes the server span after assigning it tags according to the response or error.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Method Detail

create

public static <Req,Resp> HttpServerHandler<Req,Resp> create(HttpTracing httpTracing,
                                                                        HttpServerAdapter<Req,Resp> adapter)

handleReceive

public brave.Span handleReceive(brave.propagation.TraceContext.Extractor<Req> extractor,
                                Req request)

Conditionally joins a span, or starts a new trace, depending on if a trace context was extracted from the request. Tags are added before the span is started.

This is typically called before the request is processed by the actual library.

handleReceive

public <C> brave.Span handleReceive(brave.propagation.TraceContext.Extractor<C> extractor,
                                    C carrier,
                                    Req request)

Like handleReceive(TraceContext.Extractor, Object), except for when the carrier of trace data is not the same as the request.

Request data is parsed before the span is started.

See Also:

HttpServerParser.request(HttpAdapter, Object, SpanCustomizer)

handleSend

public void handleSend(@Nullable
                       Resp response,
                       @Nullable
                       Throwable error,
                       brave.Span span)

Finishes the server span after assigning it tags according to the response or error.

This is typically called once the response headers are sent, and after the span is no longer in scope.

See Also:

HttpServerParser.response(HttpAdapter, Object, Throwable, SpanCustomizer)