›

API reference

edit

API reference

edit

Although most usage is covered automatically, Elastic APM also has a public API that allows custom usage.

Agent life cycle

edit

Controlling when the agent starts and stops.

`ElasticAPM.start`

edit

To create and start an ElasticAPM agent use ElasticAPM.start:

ElasticAPM.start(server_url: 'http://localhost:8200')

config: An optional hash or ElasticAPM::Config instance with configuration options. See Configuration.

If you are using Ruby on Rails this is done automatically for you. If you choose not to require the elastic_apm gem and instead want to start the agent and hook into Rails manually, see hooking into Rails explicitly. If you’re not using Rails, see Getting started with Rack.

`ElasticAPM.stop`

edit

Stop the currently running agent. Use this inside at_exit in your Rack app to gracefully shut down.

`ElasticAPM.restart`

edit

If the agent is already running, this method will stop and start the agent.

If the agent is not already running, this method will start the agent.

A config can be passed to the method that will be used to start the agent. If the agent is already running and no config is passed to the #restart method, the running agent’s config will be used.

`ElasticAPM.running?`

edit

Returns whether the ElasticAPM Agent is currently running.

`ElasticAPM.agent`

edit

Returns the currently running agent or nil.

Instrumentation

edit

`ElasticAPM.current_transaction`

edit

Returns the current ElasticAPM::Transaction or nil.

`ElasticAPM.start_transaction`

edit

Start a transaction eg. an incoming web request or a background job.

# call with block
ElasticAPM.start_transaction('Name')
do_work # ...
ElasticAPM.end_transaction('result')

Arguments:

name: A name for your transaction. Transactions are grouped by name. Required.
type: A type for your transaction eg. db.postgresql.sql.
context:: An optional Context used to enrich the transaction with information about the current request.
trace_context:: An optional TraceContext object for Distributed Tracing.

Returns the transaction.

`ElasticAPM.end_transaction`

edit

Ends the currently running transaction.

Arguments:

result: A String result of the transaction, eg. 'success'.

`ElasticAPM.with_transaction`

edit

Wrap a block in a Transaction, starting and ending around the block

ElasticAPM.with_transaction 'Do things' do |transaction|
  do_work # ...

  transaction.result = 'success'
end

Arguments:

name: A name for your transaction. Transactions are grouped by name. Required.
type: A type for your transaction eg. db.postgresql.sql.
context:: An optional Context used to enrich the transaction with information about the current request.
trace_context:: An optional TraceContext object for Distributed Tracing.
&block: A block to wrap. Optionally yields the transaction.

Returns the return value of the given block.

`ElasticAPM.start_span`

edit

Start a new span.

ElasticAPM.with_transaction 'Do things' do
  ElasticAPM.start_span 'Do one of the things'
  Database.query # ...
  ElasticAPM.end_span
end

Arguments:

name: A name for your span. Required.
type: The type of span eg. db.
subtype: The subtype of span eg. postgresql.
action: The action type of span eg. connect or query.
context: An instance of Span::Context.
include_stacktrace: Whether or not to collect a Stacktrace.
trace_context:: An optional TraceContext object for Distributed Tracing.
parent:: An optional parent transaction or span. Relevant when the span is created in another thread.
sync:: An boolean to indicate whether the span is created synchronously or not.
&block: An optional block to wrap with the span. The block is passed the span as an optional argument.

Returns the created span.

If you’d like to create an asynchronous span, you have to pass the parent Span or Transaction to the start_span method. You can also set the sync flag to false, if you’d like the span to be marked as asynchronous. This has no effect other than being queryable in Elasticsearch.

transaction = ElasticAPM.current_transaction # or start one with `.start_transaction`
Thread.new do
  ElasticAPM.start_span(
    'job 1',
    parent: transaction,
    sync: false
  ) { Worker.perform }
  ElasticAPM.end_span
end

`ElasticAPM.end_span`

edit

Ends the currently running span.

`ElasticAPM.with_span`

edit

Wraps a block in a Span.

Arguments:

name: A name for your span. Required.
type: The type of span eg. db.
subtype: The subtype of span eg. postgresql.
action: The action type of span eg. connect or query.
context: An instance of Span::Context.
include_stacktrace: Whether or not to collect a Stacktrace.
trace_context:: An optional TraceContext object for Distributed Tracing.
parent:: An optional parent transaction or span. Relevant when the span is created in another thread.
sync:: An boolean to indicate whether the span is created synchronously or not.
&block: An optional block to wrap with the span. The block is passed the span as an optional argument.

Returns the return value of the given block.

If you’d like to create an asynchronous span, you have to pass the parent Span or Transaction to the with_span method. You can also set the sync flag to false, if you’d like the span to be marked as asynchronous.

transaction = ElasticAPM.current_transaction # or start one with `.start_transaction`
Thread.new do
  ElasticAPM.with_span(
    'job 1',
    parent: transaction,
    sync: false
  ) { Worker.perform }
end

`ElasticAPM.build_context`

edit

Build a new Context from a Rack env.

A context provides information about the current request, response, user and more.

Arguments:

rack_env: An instance of Rack::Env
for_type: Symbol representing type of event, eg. :transaction or error

Returns the built context.

Rails

edit

Start the agent and hook into Rails manually. This is useful if you skip requiring the gem and using the Railtie.

ElasticAPM::Rails.start(server_url: 'http://localhost:8200')

Sinatra

edit

Start the agent and hook into Sinatra.

ElasticAPM::Sinatra.start(MySinatraApp, server_url: 'http://localhost:8200')

Grape

edit

Start the agent and hook into Grape.

ElasticAPM::Grape.start(MyGrapeApp, server_url: 'http://localhost:8200')

Errors

edit

`ElasticAPM.report`

edit

Send an Exception to Elastic APM.

If reported inside a transaction, the context from that will be added.

begin
  do_a_thing_and_fail
rescue Exception => e
  ElasticAPM.report(e)
end

Arguments:

exception: An instance of Exception. Required.
handled: Whether the error was handled eg. wasn’t rescued and was represented to the user. Default: true.

Returns [String] ID of the generated [ElasticAPM::Error] object.

`ElasticAPM.report_message`

edit

Send a custom message to Elastic APM.

If reported inside a transaction, the context from that will be added.

ElasticAPM.report_message('This should probably never happen?!')

Arguments:

message: A custom error string. Required.

Returns [String] ID of the generated [ElasticAPM::Error] object.

Context

edit

`ElasticAPM.set_label`

edit

Add a label to the current transaction. Labels are basic key-value pairs that are indexed in your Elasticsearch database and therefore searchable. The value can be a string, nil, numeric or boolean.

Before using custom labels, ensure you understand the different types of metadata that are available.

before_action do
  ElasticAPM.set_label(:company_id, current_user.company.id)
end

Arguments:

key: A string key. Note that ., * or " will be converted to _.
value: A value.

Returns the set value.

Be aware that labels are indexed in Elasticsearch. Using too many unique keys will result in Mapping explosion.

`ElasticAPM.set_custom_context`

edit

Add custom context to the current transaction. Use this to further specify a context that will help you track or diagnose what’s going on inside your app.

Before using custom context, ensure you understand the different types of metadata that are available.

If called several times during a transaction the custom context will be destructively merged with merge!.

before_action do
  ElasticAPM.set_custom_context(company: current_user.company.to_h)
end

Arguments:

context: A hash of JSON-compatible key-values. Can be nested.

Returns current custom context.

`ElasticAPM.set_user`

edit

Add the current user to the current transaction’s context.

Arguments:

user: An object representing the user

Returns the given user

Data

edit

`ElasticAPM.add_filter`

edit

Provide a filter to transform payloads before sending.

Arguments:

key: A unique key identifying the filter
callable: An object or proc (responds to .call(payload))

Return the altered payload.

If nil is returned all subsequent filters will be skipped and the post request cancelled.

Example:

ElasticAPM.add_filter(:filter_pings) do |payload|
  payload[:transactions]&.reject! do |t|
    t[:name] == 'PingsController#index'
  end
  payload
end

Transaction

edit

ElasticAPM.transaction returns a Transaction (if the agent is running).

Properties

edit

name: String
type: String
result: String
outcome: String (unknown, success, failure, nil)
trace_id: String (readonly)

`#sampled?`

edit

Whether the transaction is sampled eg. it includes stacktraces for its spans.

`#ensure_parent_id`

edit

If the transaction does not have a parent-ID yet, calling this method generates a new ID, sets it as the parent-ID of this transaction, and returns it as a String.

This enables the correlation of the spans the JavaScript Real User Monitoring (RUM) agent creates for the initial page load with the transaction of the backend service.

If your service generates the HTML page dynamically, initializing the JavaScript RUM agent with the value of this method allows analyzing the time spent in the browser vs in the backend services.

To enable the JavaScript RUM agent, initialize the RUM agent with the Ruby agent’s current transaction:

<script src="elastic-apm-js-base/dist/bundles/elastic-apm-js-base.umd.min.js"></script>
<script>
  var elasticApm = initApm({
    serviceName: '',
    serverUrl: 'http://localhost:8200',
    pageLoadTraceId: "<%= ElasticAPM.current_transaction&.trace_id %>",
    pageLoadSpanId: "<%= ElasticAPM.current_transaction&.ensure_parent_id %>",
    pageLoadSampled: <%= ElasticAPM.current_transaction&.sampled? %>
  })
</script>

See the JavaScript RUM agent documentation for more information.

Span

edit

Properties

edit

name: String
type: String

« Custom instrumentation Metrics »