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MeshTrace
This policy uses new policy matching algorithm. Do not combine with TrafficTrace.
This policy enables publishing traces to a third party tracing solution.
Tracing is supported over HTTP, HTTP2, and gRPC protocols. You must explicitly specify the protocol for each service and data plane proxy you want to enable tracing for.
Kong Mesh currently supports the following trace exposition formats:
-
zipkin
traces in this format can be sent to many different tracing backends datadog
Services still need to be instrumented to preserve the trace chain across requests made across different services.
You can instrument with a language library of your choice (for zipkin and for datadog). For HTTP you can also manually forward the following headers:
x-request-id
x-b3-traceid
x-b3-parentspanid
x-b3-spanid
x-b3-sampled
x-b3-flags
TargetRef support matrix
TargetRef type | top level | to | from |
---|---|---|---|
Mesh | ✅ | ❌ | ❌ |
MeshSubset | ✅ | ❌ | ❌ |
MeshService | ✅ | ❌ | ❌ |
MeshServiceSubset | ✅ | ❌ | ❌ |
To learn more about the information in this table, see the matching docs.
Configuration
Sampling
Most of the time setting only
overall
is sufficient.random
andclient
are for advanced use cases.
You can configure sampling settings equivalent to Envoy’s:
The value is always a percentage and is between 0 and 100.
Example:
sampling:
overall: 80
random: 60
client: 40
Tags
You can add tags to trace metadata by directly supplying the value (literal
) or by taking it from a header (header
).
Example:
tags:
- name: team
literal: core
- name: env
header:
name: x-env
default: prod
- name: version
header:
name: x-version
If a value is missing for header
, default
is used.
If default
isn’t provided, then the tag won’t be added.
Backends
Datadog
You can configure a Datadog backend with a url
and splitService
.
Example:
datadog:
url: http://my-agent:8080 # Required. The url to reach a running datadog agent
splitService: true # Default to false. If true, it will split inbound and outbound requests in different services in Datadog
The splitService
property determines if Datadog service names should be split based on traffic direction and destination.
For example, with splitService: true
and a backend
service that communicates with a couple of databases,
you would get service names like backend_INBOUND
, backend_OUTBOUND_db1
, and backend_OUTBOUND_db2
in Datadog.
Zipkin
In most cases the only field you’ll want to set in url
.
Example:
zipkin:
url: http://jaeger-collector:9411/api/v2/spans # Required. The url to a zipkin collector to send traces to
traceId128bit: false # Default to false which will expose a 64bits traceId. If true, the id of the trace is 128bits
apiVersion: httpJson # Default to httpJson. It can be httpJson, httpProto and is the version of the zipkin API
sharedSpanContext: false # Default to true. If true, the inbound and outbound traffic will share the same span.
Examples
Zipkin
Datadog
This assumes a Datadog agent is configured and running. If you haven’t already check the Datadog observability page.
Targeting parts of the infrastructure
While usually you want all the traces to be sent to the same tracing backend,
you can target parts of a Mesh
by using a finer-grained targetRef
and a designated backend to trace different paths of our service traffic.
This is especially useful when you want traces to never leave a world region, or a cloud, for example.
In this example, we have two zones east
and west
, each of these with their own Zipkin collector: east.zipkincollector:9411/api/v2/spans
and west.zipkincollector:9411/api/v2/spans
.
We want dataplane proxies in each zone to only send traces to their local collector.
To do this, we use a TargetRef
kind value of MeshSubset
to filter which dataplane proxy a policy applies to.