8.8.4.0 | Services | OpenTracing Service

The OpenTracing service, which adheres to the OpenTracing standard, enables reporting of tracing data to a collection service.

The initial release of the OpenTracing service only supports using the Jaeger client library. However, other Tracers can be integrated in future OpenTracing service updates. By default, the service is disabled, but it can be enabled by including an open-tracing.cfg.xml configuration. The origin service can simply pass the Tracer-specific header to downstream services and requests will be traced across application boundaries.

For backwards compatibility with the underlying configuration mechanism, the only way to disable the OpenTracing service after it has been started is to restart the Respose instance.

General Service information

Default Configuration: open-tracing.cfg.xml
Released: v8.8.3.0
Schema

OpenTracing implementation detail

This section will cover all Tracers that are supported by the OpenTracing service. We will be adding to this list as more tracers are supported.

Current support:

Table 1. Tracer information
Tracer Name	Tracer Header	Extraction examples
Jaeger	`uber-trace-id`	https://github.com/jaegertracing/jaeger-client-java/tree/master/jaeger-apachehttpclient

Examples

Basic Configuration

This configuration will send all traces to the collector at http://localhost:14268.

open-tracing.cfg.xml

<?xml version="1.0" encoding="UTF-8"?>
<open-tracing xmlns="http://docs.openrepose.org/repose/open-tracing-service/v1.0"
              service-name="myService-repose" (1)
>
    <jaeger> (2)
        <connection-http (3)
            endpoint="http://localhost:14268" (4)
        />
        <sampling-constant/> (5)
    </jaeger>
</open-tracing>

1	The required name of the service that is reporting traces. This value will be used to identify the service and should therefore be unique (e.g., identity-repose).
2	Defines the Tracer implementation to use as Jaeger.
3	Indicates to use HTTP communication with the default Collector endpoint at `http://localhost:14268`.
4	Collector endpoint.
5	Indicates to use the Constant (`const`) sampling scheme with the default of `on` which means all.

Use Basic Auth with the Collector endpoint

This configuration will send one of every 1,000 traces to the collector using Basic HTTP Authentication.

open-tracing.cfg.xml

<?xml version="1.0" encoding="UTF-8"?>
<open-tracing xmlns="http://docs.openrepose.org/repose/open-tracing-service/v1.0"
              service-name="myService-repose" (1)
>
    <jaeger
        flush-interval-ms="1000" (2)
        max-buffer-size="10000" (3)
        log-spans="true" (4)
    >
        <connection-http
            endpoint="http://localhost:14268" (5)
            username="UserName" (6)
            password="P4$$W0rd" (7)
        />
        <sampling-probabilistic
            probability="0.001" (8)
        />
    </jaeger>
</open-tracing>

1 The required name of the service that is reporting traces. This value will be used to identify the service and should therefore be unique (e.g., identity-repose).

2 How often to send span data to tracer in milliseconds.
Default: 1000

3 Maximum number of spans in buffer before sending.
Default: 10,000

4 Optionally sets up a logger for all spans.
Default: true

5 Collector endpoint.

6 Optional username sent for Basic HTTP Authentication as defined in RFC 7617.

Optional password sent for Basic HTTP Authentication as defined in RFC 7617.

The username attribute must be accompanied by a password attribute. The token attribute is mutually exclusive to the username/password attributes.

8 The Probability (probability) sampling scheme applies a probabilistic algorithm weighted between 0.0 and 1.0. With 0.0 being None and 1.0 being All.
Default: 0.001

Broadcast to the Collector endpoint

This configuration will send at most one trace per second to the collector using UDP.

open-tracing.cfg.xml

<?xml version="1.0" encoding="UTF-8"?>
<open-tracing xmlns="http://docs.openrepose.org/repose/open-tracing-service/v1.0"
              service-name="myService-repose" (1)
>
    <jaeger>
        <connection-udp (2)
            host="localhost" (3)
            port="14268" (4)
        />
        <sampling-rate-limiting
            max-traces-per-second="1.0" (5)
        />
    </jaeger>
</open-tracing>

1	The required name of the service that is reporting traces. This value will be used to identify the service and should therefore be unique (e.g., identity-repose).
2	Indicates that UDP will be used to transport data to the agent.
3	Agent target host.
4	Agent target port.
5	Utilize the Rate limited (`rate-limited`) sampling scheme. Default: `1.0`