OpenTelemetry Setup

Overview

OpenTelemetry integration wires the client's messaging operations into your tracing pipeline without hand-instrumenting every call site. In a distributed system where a message might be published by one service, queued, and consumed by three others, per-call logging tells you almost nothing — you need spans that correlate across process boundaries. The Ruby SDK doesn't ship its own OTel code; it relies entirely on the standard Ruby OpenTelemetry SDK's gRPC auto-instrumentation, which keeps the client itself lightweight.

When a TracerProvider is configured globally via OpenTelemetry::SDK.configure, every gRPC call the client makes — send_event, subscribe, and the rest — is automatically instrumented, as long as opentelemetry-instrumentation-grpc is installed alongside the core opentelemetry-sdk gem. Gotchas: OpenTelemetry::SDK.configure must run before the KubeMQ client is created, or the first calls go unrecorded; c.use_all enables every available instrumentation library on the classpath, which can be noisier than you want in production — prefer c.use 'OpenTelemetry::Instrumentation::GRPC' to scope it down; and without a configured exporter (OTLP, Jaeger, Zipkin), spans are created but never sent anywhere.

Prerequisites

• KubeMQ server running on localhost:50000
• Ruby SDK installed (gem install kubemq)
• OpenTelemetry gems: opentelemetry-sdk, opentelemetry-exporter-otlp

Code

require 'kubemq'

# The KubeMQ Ruby client supports OpenTelemetry through the standard
# Ruby OpenTelemetry SDK. When a TracerProvider is configured globally,
# gRPC calls are automatically instrumented.
#
# Setup:
#   require 'opentelemetry/sdk'
#   require 'opentelemetry/exporter/otlp'
#
#   OpenTelemetry::SDK.configure do |c|
#     c.service_name = 'kubemq-ruby-example'
#     c.use_all
#   end

puts 'OpenTelemetry configured'

address = ENV.fetch('KUBEMQ_ADDRESS', 'localhost:50000')

begin
  client = KubeMQ::PubSubClient.new(address: address, client_id: 'otel-example')
  puts "Connected to #{address}"

  msg = KubeMQ::PubSub::EventMessage.new(
    channel: 'ruby-observability.opentelemetry-setup',
    metadata: 'otel-demo',
    body: 'traced-event'
  )
  client.send_event(msg)
  puts 'Event sent with tracing enabled'
rescue KubeMQ::Error => e
  puts "KubeMQ error: #{e.message}"
ensure
  client&.close
  puts 'Done'
end

How It Works

• The Ruby SDK integrates with OpenTelemetry through the standard Ruby OpenTelemetry SDK.
• When a TracerProvider is configured globally, gRPC calls are automatically instrumented.
• Install opentelemetry-instrumentation-grpc for automatic gRPC span creation.
• Configure an exporter (OTLP, Jaeger, Zipkin) to view traces in your observability platform.
• Review timeouts, channel names, and client IDs before running against shared environments.

Related

• Ruby SDK Reference
• Basic Pub/Sub