OpenTelemetry Ruby distro for Uptrace

This document explains how to configure OpenTelemetry Ruby SDK to export spans and metrics to Uptrace using OTLP/HTTP.

To learn about OpenTelemetry API, see OpenTelemetry Ruby Tracing APIopen in new window and OpenTelemetry Ruby Metrics APIopen in new window.

Uptrace Ruby

uptrace-rubyopen in new window is a thin wrapper over opentelemetry-rubyopen in new window that configures OpenTelemetry SDK to export data to Uptrace. It does not add any new functionality and is provided only for your convenience.

Add to Gemfile:

gem 'uptrace'

Or install the gem:

gem install uptrace

Configuration

You can configure Uptrace client using a DSN (Data Source Name) from the project settings page.

require 'uptrace'

# copy your project DSN here or use UPTRACE_DSN env var
Uptrace.configure_opentelemetry(dsn: 'https://token@api.uptrace.dev/project_id') do |c|
  # c is OpenTelemetry::SDK::Configurator
  c.service_name = 'myservice'
  c.service_version = '1.0.0'

  c.resource = OpenTelemetry::SDK::Resources::Resource.create(
    'deployment.environment' => 'production'
  )
end

You can also use environment variables to configure the client:

Env var	Description
`UPTRACE_DSN`	A data source that is used to connect to uptrace.dev. For example, `https://<token>@uptrace.dev/<project_id>`.
`OTEL_RESOURCE_ATTRIBUTES`	Key-value pairs to be used as resource attributes. For example, `service.name=myservice,service.version=1.0.0`.
`OTEL_SERVICE_NAME=myservice`	Sets the value of the service.name resource attribute. Takes precedence over `OTEL_RESOURCE_ATTRIBUTES`.
`OTEL_PROPAGATORS`	Propagators to be used as a comma separated list. The default is `tracecontext,baggage`.

See OpenTelemetry documentationopen in new window for details.

Quickstart

Spend 5 minutes to install OpenTelemetry distro, generate your first trace, and click the link in your terminal to view the trace.

Step 0. Createopen in new window an Uptrace project to obtain a DSN (connection string), for example, https://token@api.uptrace.dev/project_id.
Step 1. Add uptraceopen in new window to the Gemfile:

gem 'uptrace'

Step 2. Copy the codeopen in new window to main.rb replacing the <dsn>:

#!/usr/bin/env ruby
# frozen_string_literal: true

require 'rubygems'
require 'bundler/setup'
require 'uptrace'

# Configure OpenTelemetry with sensible defaults.
# Copy your project DSN here or use UPTRACE_DSN env var.
Uptrace.configure_opentelemetry(dsn: 'https://token@api.uptrace.dev/project_id') do |c|
  # c is OpenTelemetry::SDK::Configurator
  c.service_name = 'myservice'
  c.service_version = '1.0.0'

  c.resource = OpenTelemetry::SDK::Resources::Resource.create(
    'deployment.environment' => 'production'
  )
end

# Create a tracer. Usually, tracer is a global variable.
tracer = OpenTelemetry.tracer_provider.tracer('my_app_or_gem', '0.1.0')

# Create a root span (a trace) to measure some operation.
tracer.in_span('main-operation', kind: :client) do |main|
  tracer.in_span('GET /posts/:id') do |child1|
    child1.set_attribute('http.method', 'GET')
    child1.set_attribute('http.route', '/posts/:id')
    child1.set_attribute('http.url', 'http://localhost:8080/posts/123')
    child1.set_attribute('http.status_code', 200)
    child1.record_exception(ArgumentError.new('error1'))
  end

  tracer.in_span('SELECT') do |child2|
    child2.set_attribute('db.system', 'mysql')
    child2.set_attribute('db.statement', 'SELECT * FROM posts LIMIT 100')
  end

  puts("trace URL: #{Uptrace.trace_url(main)}")
end

# Send buffered spans and free resources.
OpenTelemetry.tracer_provider.shutdown

Step 3. Run the code to get a link for the generated trace:

ruby main.rb
trace URL: https://uptrace.dev/traces/<trace_id>

Step 4. Follow the link to view the generated trace:

Basic trace

Already using OTLP exporter?

If you are already using OTLP exporter, you can continue to use it with Uptrace by changing some configuration options.

To maximize performance and efficiency, consider the following recommendations when configuring OpenTelemetry SDK.

Recommendation	Signals	Significance
Use `BatchSpanProcessor` to export multiple spans in a single request.	All	Essential
Enable `gzip` compression to compress the data before sending and reduce the traffic cost.	All	Essential
Prefer `delta` metrics temporality, because such metrics are smaller and Uptrace must convert `cumulative` metrics to `delta` anyway.	Metrics	Recommended
Use AWS X-Ray ID generator for OpenTelemetry.	Traces, Logs	Optional

To configure OpenTelemetry to send data to Uptrace, use the provided endpoint and pass the DSN via uptrace-dsn header:

# Only for OTLP/gRPC
export OTEL_EXPORTER_OTLP_ENDPOINT="otlp.uptrace.dev:4317"

# Only for OTLP/HTTP
export OTEL_EXPORTER_OTLP_ENDPOINT="https://otlp.uptrace.dev"

# Pass Uptrace DSN in gRPC/HTTP headers.
export OTEL_EXPORTER_OTLP_HEADERS="uptrace-dsn=https://token@api.uptrace.dev/project_id"

# Enable gzip compression.
export OTEL_EXPORTER_OTLP_COMPRESSION=gzip

# Enable exponential histograms.
export OTEL_EXPORTER_OTLP_METRICS_DEFAULT_HISTOGRAM_AGGREGATION=BASE2_EXPONENTIAL_BUCKET_HISTOGRAM

# Prefer delta temporality.
export OTEL_EXPORTER_OTLP_METRICS_TEMPORALITY_PREFERENCE=DELTA

When configuring BatchSpanProcessor, use the following settings:

# Maximum allowed time to export data in milliseconds.
export OTEL_BSP_EXPORT_TIMEOUT=5000

# Maximum batch size.
# Using larger batch sizes can be problematic,
# because Uptrace rejects requests larger than 20MB.
export OTEL_BSP_MAX_EXPORT_BATCH_SIZE=10000

# Maximum queue size.
# Increase queue size if you have lots of RAM, for example,
# `10000 * number_of_gigabytes`.
export OTEL_BSP_MAX_QUEUE_SIZE=30000

# Max concurrent exports.
# Setting this to the number of available CPUs might be a good idea.
export OTEL_BSP_MAX_CONCURRENT_EXPORTS=2

Exporting traces

Hereopen in new window is how you can configure OTLP/gRPC exporter for Uptrace following the recommendations above:

#!/usr/bin/env ruby
# frozen_string_literal: true

require 'rubygems'
require 'bundler/setup'
require 'opentelemetry/sdk'
require 'opentelemetry/exporter/otlp'
require 'opentelemetry-propagator-xray'

dsn = ENV.fetch('UPTRACE_DSN')
puts("using dsn: #{dsn}")

exporter = OpenTelemetry::Exporter::OTLP::Exporter.new(
  endpoint: 'https://otlp.uptrace.dev/v1/traces',
  # Set the Uptrace DSN here or use UPTRACE_DSN env var.
  headers: { 'uptrace-dsn': dsn },
  compression: 'gzip'
)
span_processor = OpenTelemetry::SDK::Trace::Export::BatchSpanProcessor.new(
  exporter,
  max_queue_size: 1000,
  max_export_batch_size: 1000
)

OpenTelemetry::SDK.configure do |c|
  c.service_name = 'myservice'
  c.service_version = '1.0.0'
  c.id_generator = OpenTelemetry::Propagator::XRay::IDGenerator

  c.add_span_processor(span_processor)
end

tracer = OpenTelemetry.tracer_provider.tracer('my_app_or_gem', '1.0.0')

tracer.in_span('main') do |span|
  puts("trace id: #{span.context.hex_trace_id}")
end

# Send buffered spans and free resources.
OpenTelemetry.tracer_provider.shutdown

What's next?

Next, instrument more operations to get a more detailed picture. Try to prioritize network calls, disk operations, database queries, error and logs.

You can also create your own instrumentations using OpenTelemetry Ruby Tracing APIopen in new window.

# OpenTelemetry Ruby distro for Uptrace

# Uptrace Ruby

# Configuration

# Quickstart

# Already using OTLP exporter?

# Exporting traces

# What's next?