Package io.honeycomb.beeline.tracing.propagation

Class HttpClientPropagator

java.lang.Object

io.honeycomb.beeline.tracing.propagation.HttpClientPropagator

public class HttpClientPropagator
extends Object

Provides straightforward instrumentation of an an HTTP client call, while also adding a standardized set of span fields.

Example instrumentation for a synchronous client call:

 HttpClientRequestAdapter adaptedHttpRequest = new HttpClientRequestAdapter(actualHttpRequest);
 HttpClientResponseAdapter adaptedHttpResponse = null;
 Throwable error = null;
 Span span = clientPropagator.startPropagation(adaptedHttpRequest);
 try {
   actualHttpResponse = makeClientCall(actualHttpRequest);
   adaptedHttpResponse = new HttpClientResponseAdapter(actualHttpResponse);
 } catch (Exception ex) {
   error = ex;
   throw ex;
 } finally {
   clientPropagator.endPropagation(adaptedHttpResponse, error, span);
 }
 

The API is based on Brave's HTTP utilities under brave.http.

Field Summary

Fields

Modifier and Type	Field	Description
static String	HTTP_CLIENT_SPAN_TYPE

Constructor Summary

Constructors

Modifier	Constructor	Description
protected	HttpClientPropagator(Tracer tracer, PropagationCodec<String> propagationCodec, Function<HttpClientRequestAdapter,String> requestToSpanName)
	HttpClientPropagator(Tracer tracer, Function<HttpClientRequestAdapter,String> requestToSpanName)	Create an HttpClientPropagator for tracing HTTP client requests.

Method Summary

Modifier and Type	Method	Description
void	endPropagation(HttpClientResponseAdapter httpResponse, Throwable error, Span span)	Adds standard span fields based on data in the HTTP response or the error.
Span	startPropagation(HttpClientRequestAdapter httpRequest)	Creates a child span for this HTTP client request and adds the standardized fields to it.

Methods inherited from class java.lang.Object

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

Field Detail

HTTP_CLIENT_SPAN_TYPE

public static final String HTTP_CLIENT_SPAN_TYPE

See Also:

Constant Field Values

Constructor Detail

HttpClientPropagator

public HttpClientPropagator(Tracer tracer,
                            Function<HttpClientRequestAdapter,String> requestToSpanName)

Create an HttpClientPropagator for tracing HTTP client requests.

requestToSpanName allows you to dynamically name the HTTP client spans such that the name reflects the operation, e.g. based on HTTP method or request path used.

Parameters:

tracer - the tracer

requestToSpanName - a function from request to span name

HttpClientPropagator

protected HttpClientPropagator(Tracer tracer,
                               PropagationCodec<String> propagationCodec,
                               Function<HttpClientRequestAdapter,String> requestToSpanName)

Method Detail

startPropagation

public Span startPropagation(HttpClientRequestAdapter httpRequest)

Creates a child span for this HTTP client request and adds the standardized fields to it.

Parameters:

httpRequest - the adapted HTTP client request

Returns:

the child span

endPropagation

public void endPropagation(HttpClientResponseAdapter httpResponse,
                           Throwable error,
                           Span span)

Adds standard span fields based on data in the HTTP response or the error. Closes the HTTP client call span.

The httpResponse and the error are both allowed to be null.

Parameters:

httpResponse - the adapted HTTP response, may be null

error - an error that was thrown during the HTTP client call, may be null

span - the span for the HTTP client call