XRayRecorder_TraceContext

XRayRecorder.TraceContext

X-Ray Trace Context propagated in a tracing header.

public struct TraceContext

Tracing header

All requests are traced, up to a configurable minimum. After reaching that minimum, a percentage of requests are traced to avoid unnecessary cost. The sampling decision and trace ID are added to HTTP requests in tracing headers named X-Amzn-Trace-Id. The first X-Ray-integrated service that the request hits adds a tracing header, which is read by the X-Ray SDK and included in the response.

Example Tracing header with root trace ID and sampling decision:​

X-Amzn-Trace-Id:​ Root=1-5759e988-bd862e3fe1be46a994272793;Sampled=1

Tracing Header Security

A tracing header can originate from the X-Ray SDK, an AWS service, or the client request. Your application can remove X-Amzn-Trace-Id from incoming requests to avoid issues caused by users adding trace IDs or sampling decisions to their requests.

The tracing header can also contain a parent segment ID if the request originated from an instrumented application. For example, if your application calls a downstream HTTP web API with an instrumented HTTP client, the X-Ray SDK adds the segment ID for the original request to the tracing header of the downstream request. An instrumented application that serves the downstream request can record the parent segment ID to connect the two requests.

Example Tracing header with root trace ID, parent segment ID and sampling decision

X-Amzn-Trace-Id:​ Root=1-5759e988-bd862e3fe1be46a994272793;Parent=53995c3f42cd8ad8;Sampled=1

References

• AWS X-Ray concepts - Tracing header

Initializers

init(traceId:​parentId:​sampled:​)

Creates new Trace Context.

public init(traceId:​ TraceID = .init(), parentId:​ Segment.ID? = nil, sampled:​ Bool = true)

Parameters

• traceId:​ - traceId:​ root trace ID
• parentId:​ - parentId:​ parent segment ID
• sampled:​ - sampled:​ sampling decision

init(tracingHeader:​)

Parses and validates string with Tracing Header.

public init(tracingHeader:​ String) throws

Parameters

• string:​ - string:​ string with TraceContext.

Throws

may throw XRayRecorder.TraceError if the value is invalid.

Properties

traceId

Root trace ID.

let traceId:​ TraceID

parentId

Parent segment ID.

var parentId:​ Segment.ID?

isSampled

sampled flag.

var isSampled:​ Bool

tracingHeader

Tracing header value.

var tracingHeader:​ String