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HttpClient

Semantic Span Attributes

Attribute Key/Name Attribute Value Obfuscated/Unset when -Dfr.observability.trace.attributes.semantics.obfuscation.enabled=true
net.peer.name Remote hostname. True
net.peer.port Remote port. True
http.method HTTP request method. False
http.url Full HTTP request URL. Query String
http.flavor HTTP response protocol. False
http.status_code HTTP response status code. False
http.request.header.{header_key} The HTTP header value corresponding to the specified request header key. False
http.response.header.{header_key} The HTTP header value corresponding to the specified response header key. False

Span Name

Span names for HttpClient are HTTP followed by the HTTP request method e.g HTTP GET.

Specifying HTTP Header Attributes

An HTTP header attribute will be set on a span if there's a header on the request/response whose header key matches one of the user-specified header keys.

Methods to Specify Header Keys:

  • Within the on premise FusionReactor UI, go to Requests Settings and specify the headers within the Add Request/Response Header Names form inputs and save.
  • Within the reactor.conf, set request.header.names={comma-separated list of header keys/names} for request headers and response.header.names={comma-separated list of header keys/names} for response headers.
  • With System Properties, set -Dfr.observability.trace.attributes.request.headers={comma-separated list of header keys/names} for request headers and -Dfr.observability.trace.attributes.response.headers={comma-separated list of header keys/names} for response headers.

Things to be aware of

  • The header_keys in http.request.header.{header_key} and http.response.header.{header_key} are forced to lowercase and have their - characters replaced with _.
  • You can combine specifying header keys via system properties and FusionReactor configuration.
  • HttpClient async Pipelining is not properly supported by tracing. Spans are created for the usual transactions within FusionReactor but no propagation occurs between the executing process and callbacks.
  • Spans generated within the async callback are appended to the HTTP request span as a child.

Properties for HttpClient

Check the attributes page for general properties that can affect HttpClient transactions.

Property Key Default Description
fr.observability.trace.attributes.request.headers "" Comma separated list of request header names to match and attach header to WebRequest, OkHttp and Httpclient span attributes.
fr.observability.trace.attributes.response.headers "" Comma separated list of response header names to match and attach header to WebRequest, OkHttp and Httpclient span attributes.

Example Span
An example of a HttpClient async trace. The HTTP GET request has propagated the trace to the destination service as well as to the callback. Each are represented as child spans of the request.