Public APIedit

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

Agent life cycleedit

Controlling when the agent starts and stops.

ElasticAPM.startedit

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 not see Getting started with Rack.

ElasticAPM.stopedit

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

ElasticAPM.running?edit

Returns whether the ElasticAPM Agent is currently running.

ElasticAPM.agentedit

Returns the currently running agent or nil.

Instrumentationedit

ElasticAPM.current_transactionedit

Returns the current ElasticAPM::Transaction or nil.

ElasticAPM.transactionedit

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

If called without a block you are expected to end the transaction yourself. If given a block, the code inside will be wrapped in a transaction.

You need to submit it yourself with transaction.submit(status).

# call with block
transaction = ElasticAPM.transaction('Do things') do
  do_work # ...
end # .done is called when block ends

transaction.submit(200)

# without block
transaction = ElasticAPM.transaction('Do things')
do_work
transaction.submit(200) # .submit(result) will also .done(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.
  • &block: An optional block to wrap with the transaction. The block is passed the transaction as an optional argument.

Returns the transaction.

ElasticAPM.spanedit

Most transactions have nested spans signifying work of a specific sort eg. database queries or external web requests.

If given a block, wrap the code inside in a span. If not you are expected to close the span yourself with span.done(result).

ElasticAPM.transaction 'Do things' do
  ElasticAPM.span 'Do one of the things' do
    Database.query # ...
  end
end

Arguments:

  • name: A name for your span. Required.
  • type: The type of work eg. db.postgresql.query.
  • context: An instance of Span::Context.
  • include_stacktrace: Whether or not to collect a Stacktrace.
  • &block: An optional block to wrap with the span. The block is passed the span as an optional argument.

Return the span or the return value of the given block.

ElasticAPM.build_contextedit

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

Returns the built context.

Errorsedit

ElasticAPM.reportedit

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 [ElasticAPM::Error].

ElasticAPM.report_messageedit

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 [ElasticAPM::Error].

Contextedit

ElasticAPM.set_tagedit

Add a tag to the current transaction. Tags are basic key-value pairs that are indexed in your Elasticsearch database and therefore searchable.

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

Arguments:

  • key: A string key.
  • value: A string value.

Returns the set value.

ElasticAPM.set_custom_contextedit

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.

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_useredit

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

Arguments:

  • user: An object representing the user

Returns the given user

Dataedit

ElasticAPM.add_filteredit

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

Transactionedit

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

Propertiesedit

  • name: String
  • type: String

#releaseedit

Makes sure the transaction is no longer ElasticAPM.current_transaction.

#done(result)edit

Args:

  • result: String result of transaction, eg. success. Default: nil.

Ends the transaction, settings its duration to µs since it began and sets its result.

Returns self.

#done?edit

Returns whether the transaction is done.

#submit(result, status:, headers:)edit

Args:

  • result: String result of transaction, eg. success. Default: nil.
  • status: HTTP status code (for request transactions). Default: nil.
  • headers: HTTP headers (for request transactions). Default: {}.

Ends transaction with done, adds HTTP request information, releases it and submits it to the queue of transactions waiting to be sent to APM Server.

Returns self.

#sampled?edit

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

Spanedit

Propertiesedit

  • name: String
  • type: String

Contextedit

A Context provides more information to transactions. Build one with ElasticAPM.build_context.