Package brave.propagation.aws

Class AWSPropagation<K>

java.lang.Object

brave.propagation.aws.AWSPropagation<K>

All Implemented Interfaces:

brave.propagation.Propagation<K>

public final class AWSPropagation<K>
extends Object
implements brave.propagation.Propagation<K>

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 timeis 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.Factory, brave.propagation.Propagation.Getter<C extends Object,K extends Object>, brave.propagation.Propagation.KeyFactory<K extends Object>, brave.propagation.Propagation.Setter<C extends Object,K extends Object>

Field Summary

Fields

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

Fields inherited from interface brave.propagation.Propagation

B3_SINGLE_STRING, B3_STRING

Method Summary

Modifier and Type	Method	Description
static String	currentTraceId()	Returns the current traceId(TraceContext) or null if not available
static brave.propagation.TraceContextOrSamplingFlags	extract(String amznTraceId)	Like TraceContext.Extractor.extract(Object) except reading from a single field.
static brave.propagation.TraceContextOrSamplingFlags	extractLambda()	This is used for extracting from the AWS lambda environment variable _X_AMZN_TRACE_ID.
<C> brave.propagation.TraceContext.Extractor<C>	extractor(brave.propagation.Propagation.Getter<C,K> getter)
<C> brave.propagation.TraceContext.Injector<C>	injector(brave.propagation.Propagation.Setter<C,K> setter)
List<K>	keys()	returns the name of the header field: "x-amzn-trace-id"
static String	traceId(brave.propagation.TraceContext context)	Used for log correlation or tag values

Methods inherited from class java.lang.Object

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

Field Detail

FACTORY

public static final brave.propagation.Propagation.Factory FACTORY

ROOT_LENGTH

public static final int ROOT_LENGTH

See Also:

Constant Field Values

Method Detail

keys

public List<K> keys()

returns the name of the header field: "x-amzn-trace-id"

Specified by:

keys in interface brave.propagation.Propagation<K>

injector

public <C> brave.propagation.TraceContext.Injector<C> injector(brave.propagation.Propagation.Setter<C,K> setter)

Specified by:

injector in interface brave.propagation.Propagation<K>

currentTraceId

@Nullable
public static String currentTraceId()

Returns the current traceId(TraceContext) or null if not available

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 <C> brave.propagation.TraceContext.Extractor<C> extractor(brave.propagation.Propagation.Getter<C,K> getter)

Specified by:

extractor in interface brave.propagation.Propagation<K>

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.