Jaeger::Client

OpenTracing Tracer implementation for Jaeger in Ruby

Installation

Add this line to your application's Gemfile:

gem 'jaeger-client'

Usage

require 'jaeger/client'
OpenTracing.global_tracer = Jaeger::Client.build(host: 'localhost', port: 6831, service_name: 'echo')

OpenTracing.start_active_span('span name') do
  # do something

  OpenTracing.start_active_span('inner span name') do
    # do something else
  end
end

The tracer can also take an externally configured sender. For example, the HttpSender can be configured with a different endpoint and headers for authentication.

require 'jaeger/client'
require 'jaeger/client/http_sender'

headers = { "auth_token" => token }
encoder = Jaeger::Client::Encoders::ThriftEncoder.new(service_name: "service_name")
sender = Jaeger::Client::HttpSender.new(url: "http://localhost:14268/api/traces", headers: headers, encoder: encoder)

OpenTracing.global_tracer = Jaeger::Client.build(service_name: "service_name", sender: sender)

See opentracing-ruby for more examples.

Samplers

Const sampler

Const sampler always makes the same decision for new traces depending on the initialization value. Set sampler to: Jaeger::Client::Samplers::Const.new(true) to mark all new traces as sampled.

Probabilistic sampler

Probabilistic sampler samples traces with probability equal to rate (must be between 0.0 and 1.0). This can be enabled by setting Jaeger::Client::Samplers::Probabilistic.new(rate: 0.1)

Zipkin HTTP B3 compatible header propagation

Jaeger Tracer supports Zipkin B3 Propagation HTTP headers, which are used by a lot of Zipkin tracers. This means that you can use Jaeger in conjunction with OpenZipkin tracers.

To set it up you need to change FORMAT_RACK injector and extractor.

OpenTracing.global_tracer = Jaeger::Client.build(
  service_name: 'service_name',
  injectors: {
    OpenTracing::FORMAT_RACK => [Jaeger::Client::Injectors::B3RackCodec]
  },
  extractors: {
    OpenTracing::FORMAT_RACK => [Jaeger::Client::Extractors::B3RackCodec]
  }
)

It's also possible to set up multiple injectors and extractors. Each injector will be called in sequence. Note that if multiple injectors are using the same keys then the values will be overwritten.

If multiple extractors is used then the span context from the first match will be returned.

Development

After checking out the repo, run bin/setup to install dependencies. Then, run rake spec to run the tests. You can also run bin/console for an interactive prompt that will allow you to experiment.

To install this gem onto your local machine, run bundle exec rake install. To release a new version, update the version number in version.rb, and then run bundle exec rake release, which will create a git tag for the version, push git commits and tags, and push the .gem file to rubygems.org.

Contributing

Bug reports and pull requests are welcome on GitHub at https://github.com/salemove/jaeger-client-ruby

License

The gem is available as open source under the terms of the MIT License.