Configurationedit

There are several ways to configure how Elastic APM behaves.

The recommended way to configure Elastic APM is to create a file config/elastic_apm.yml and specify options in there:

---
server_url: 'http://localhost:8200'
secret_token: 'very_very_secret'

Options are applied in the following order (last one wins):

Ruby on Railsedit

When using Rails it’s also possible to specify options inside config/application.rb:

# config/application.rb
config.elastic_apm.service_name = 'MyApp'

Sinatra and Rackedit

When using APM with Sinatra and Rack you can configure it when starting the agent:

# config.ru or similar
ElasticAPM.start(
  app: MyApp,
  service_name: 'SomeOtherName'
)

See Getting started with Rack.

Optionsedit

Some options can be set with ENV variables and all of them may be set in your source code.

When setting values for lists using ENV variables, strings are split by comma eg ELASTIC_APM_ENBALED_ENVIRONMENTS=development,production.

config_fileedit

Path to the configuration Yaml-file. Elastic APM will load config options from this if the file exists.

server_urledit

The URL for your APM Server. The URL must be fully qualified, including protocol (http or https) and port.

secret_tokenedit

This string is used to ensure that only your agents can send data to your APM server. Both the agents and the APM server have to be configured with the same secret token. One example to generate a secure secret token is:

ruby -r securerandom -e 'print SecureRandom.uuid'

Secret tokens only provide any real security if your APM server use TLS.

service_nameedit

The name of your service. This is used to keep all the errors and transactions of your service together and is the primary filter in the Elastic APM user interface.

If you’re using Ruby on Rails this will default to your app’s name. If you’re using Sinatra it will default to the name of your app’s class.

The service name must conform to this regular expression: ^[a-zA-Z0-9 _-]+$. In less regexy terms: Your service name must only contain characters from the ASCII alphabet, numbers, dashes, underscores and spaces.

service_versionedit

Deployed version of your service. Defaults to git rev-parse --verify HEAD.

environmentedit

The name of the environment this service is deployed in, e.g. "production" or "staging".

Defaults to ENV['RAILS_ENV'] || ENV['RACK_ENV'].

enabled-environmentsedit

Specify which environments to enable APM in.

If the current envrironment isn’t included, the agent will effectively be a noop and do nothing. So you can keep in your custom instrumentation code without the agent sending anything nor complain.

framework_nameedit

Name of the used framework. For Rails or Sinatra, this defaults to Ruby on Rails and Sinatra respectively, otherwise defaults to nil.

framework_versionedit

Version number of the used framework. For Ruby on Rails and Sinatra, this defaults to the used version of the framework, otherwise, the default is nil.

hostnameedit

The host name to use when sending error and transaction data to the APM server.

log_pathedit

A path to a log file.

By default Elastic APM logs to stdout or uses Rails.log when used with Rails.

Should support both absolute and relative paths. Just make sure the directory exists.

log_leveledit

By default Elastic APM logs to stdout or uses Rails.log when used with Rails.

loggeredit

By default Elastic APM logs to stdout or uses Rails.log when used with Rails.

Use this to provide another logger. Expected to have the same API as Ruby’s built-in Logger.

source_lines_error_app_framesedit

source_lines_error_library_framesedit

source_lines_span_app_framesedit

source_lines_span_library_framesedit

By default, the APM agent collects source code snippets for errors. With the above settings, you can modify how many lines of source code is collected.

We differ between errors and spans, as well as library frames and app frames.

Especially for spans, collecting source code can have a large impact on storage use in your Elasticsearch cluster.

span_frames_min_durationedit

Use this to disable stacktrace collection for spans with a duration shorter than or equal to the given amount of milleseconds.

The default is 5ms.

Set it to -1 to disable the feature and collect stack traces for all spans. Setting it to a positive value, e.g. 5, will limit stack trace collection to spans with durations equal or longer than the given value in milliseconds, e.g. 5 milliseconds.

To disable stack trace collection for spans completely, set the value to 0.

max_queue_sizeedit

Maximum queue length of transactions before sending transactions to the APM server. A lower value will increase the load on your APM server, while a higher value can increase the memory pressure of your app. A higher value also impacts the time until transactions are indexed and searchable in Elasticsearch.

This setting is useful to limit memory consumption if you experience a sudden spike of traffic.

flush_intervaledit

Interval with which transactions should be sent to the APM server, in seconds. A lower value will increase the load on your APM server, while a higher value can increase the memory pressure on your app. A higher value also impacts the time until transactions are indexed and searchable in Elasticsearch.

transaction_sample_rateedit

By default, the agent will sample every transaction (e.g. request to your service). To reduce overhead and storage requirements, you can set the sample rate to a value between 0.0 and 1.0. We still record overall time and the result for unsampled transactions, but no context information, tags, or spans.

transaction_max_spansedit

Limits the amount of spans that are recorded per transaction. This is helpful in cases where a transaction creates a very high amount of spans (e.g. thousands of SQL queries). Setting an upper limit will prevent overloading the agent and the APM server with too much work for such edge cases.

verify_server_certedit

By default, the agent verifies the SSL certificate if you use an HTTPS connection to the APM server. Verification can be disabled by changing this setting to false.

disabled_spiesedit

Elastic APM automatically instruments select third party libraries. Use this option to disable any of these.

Get an array of enabled spies with ElasticAPM.agent.config.enabled_spies.

instrumented_rake_tasksedit

Elastic APM can instrument your Rake tasks but given that they are used for a multitude of sometimes very different and not always relevant things, this is opt in.

default_tagsedit

Add default tags to add to every transaction.

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

custom_key_filtersedit

Elastic APM strips what looks like confidential information from the request/response headers. Use this option to add your own custom header keys to the list of filtered keys.

When setting this option via ENV, use a comma separated string. Eg. ELASTIC_APM_CUSTOM_KEY_FILTERS="a,b" # => [/a/, /b/]

ignore_url_patternsedit

Use this option to ignroe certain URL patterns eg. healthchecks or admin sections.

Ignoring in this context means don’t wrap in a Transaction. Errors will still be reported.

When setting this option via ENV, use a comma separated string. Eg. ELASTIC_APM_IGNORE_URL_PATTERNS="a,b" # => [/a/, /b/]

filter_exception_typesedit

Use this to filter error tracking for specific error constants.

disable_sendedit

Disables sending payloads to APM Server.