Package brave.propagation.aws

Class AWSPropagation

  • All Implemented Interfaces:
    brave.propagation.Propagation<String>
    public final class AWSPropagation
extends Object
implements brave.propagation.Propagation<String>
    Utility for working with Amazon Web Services Trace IDs, for example reading from headers or environment variables. x-amzn-trace-id is primarily for Amazon's X-Ray service, but it is also integrated with AWS ALB, API Gateway and Lambda.

    For example, if you are in a lambda environment, you can read the incoming context like this: 

    
 span = tracer.nextSpan(AWSPropagation.extractLambda());

    Details

    x-amzn-trace-id (and the lambda equivalent _X_AMZN_TRACE_ID) follows RFC 6265 style syntax (https://tools.ietf.org/html/rfc6265#section-2.2): fields are split on semicolon and optional whitespace.

    Description of the Root (or Self) field from AWS CLI help:

    A trace_id consists of three numbers separated by hyphens. For example, 1-58406520-a006649127e371903a2de979. This includes: 

     
      
 
    • The version number, i.e. 1
      • 
 
    • The time of the original request, in Unix epoch time, in 8  hexadecimal digits. For example,
 10:00AM December 2nd, 2016 PST in epoch time is 1480615200 seconds, or 58406520 in
 hexadecimal.
      • 
 
    • A 96-bit identifier for the trace, globally unique, in 24 hexadecimal digits.
      •

    • Nested Class Summary

      • Nested classes/interfaces inherited from interface brave.propagation.Propagation

        brave.propagation.Propagation.Getter<R extends Object,​K extends Object>, brave.propagation.Propagation.KeyFactory<K extends Object>, brave.propagation.Propagation.RemoteGetter<R extends Object>, brave.propagation.Propagation.RemoteSetter<R extends Object>, brave.propagation.Propagation.Setter<R extends Object,​K extends Object>

    • Field Summary

      Fields 
      Modifier and Type Field Description
      static brave.propagation.Propagation.Factory FACTORY  

      • Fields inherited from interface brave.propagation.Propagation

        B3_SINGLE_STRING, B3_STRING

    • Field Detail

      • FACTORY

        public static final brave.propagation.Propagation.Factory FACTORY

    • Method Detail

      • keys

        public List<String> keys()
        returns the name of the header field: "x-amzn-trace-id"
        Specified by:
        keys in interface brave.propagation.Propagation<String>

      • injector

        public <R> brave.propagation.TraceContext.Injector<R> injector​(brave.propagation.Propagation.Setter<R,​String> setter)
        Specified by:
        injector in interface brave.propagation.Propagation<String>

      • traceId

        @Nullable
public static String traceId​(brave.propagation.TraceContext context)
        Used for log correlation or tag values
        Returns:
        a formatted Root field like "1-58406520-a006649127e371903a2de979" or null if the context was not created from an instance of AWSPropagation.

      • extractor

        public <R> brave.propagation.TraceContext.Extractor<R> extractor​(brave.propagation.Propagation.Getter<R,​String> getter)
        Specified by:
        extractor in interface brave.propagation.Propagation<String>

      • extractLambda

        public static brave.propagation.TraceContextOrSamplingFlags extractLambda()
        This is used for extracting from the AWS lambda environment variable _X_AMZN_TRACE_ID.
        See Also:
        extract(String)

      • extract

        public static brave.propagation.TraceContextOrSamplingFlags extract​(String amznTraceId)
        Like TraceContext.Extractor.extract(Object) except reading from a single field.