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: <%= ENV["VERY_SECRET_TOKEN"] %>

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_ENABLED_ENVIRONMENTS=development,production.

config_fileedit

Path to the configuration YAML-file. Elastic APM will load config options from this if the file exists. The file will be evaluated as ERB, so you can include ENV variables like in your database.yml, eg:

secret_token: <%= ENV['VERY_SECRET_TOKEN'] %>

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.

activeedit

Whether or not to start the agent. If active is false, ElasticAPM.start will do nothing and all calls to the root API will return nil.

api_buffer_sizeedit

Maximum amount of objects kept in queue, before sending to APM Server.

If you hit this limit you either have to increase the agent’s worker pool size or it could mean the agent has trouble connecting to APM Server. The logs should tell you what went wrong.

api_request_sizeedit

Maximum amount of bytes sent over one request to APM Server. When reached the agent will open a new request.

It has to be provided in size format.

api_request_timeedit

Maximum duration of a single streaming request to APM Server before opening a new one.

APM Server has its own limit of 30 seconds before it will close requests.

It has to be provided in duration format.

capture_bodyedit

For transactions that are HTTP requests, the Ruby agent can optionally capture the request body (e.g. POST variables or JSON data).

Possible values: "errors", "transactions", "all", "off".

If the request has a body and this setting is disabled, the body will be shown as [SKIPPED].

request bodies often contain sensitive values like passwords, credit card numbers etc. We try to strip sensitive looking data from form bodies but don’t touch text bodies like JSON. If your service handles data like this, we advise to only enable this feature with care.

capture_headersedit

Whether or not to attach the request headers to transactions and errors.

capture_envedit

Whether or not to attach ENV from Rack to transactions and errors.

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/]

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.

disable_sendedit

Disables sending payloads to APM Server.

disable_start_messageedit

Disables the agent’s startup message announcing itself.

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.

environmentedit

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

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

Kibana will not differentiate between different environments. To avoid mixing data from multiple environments, consider appending the environment to service_name.

filter_exception_typesedit

Use this to filter error tracking for specific error constants.

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.

ignore_url_patternsedit

Use this option to ignore 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/]

instrumentedit

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

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.

log_leveledit

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

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.

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.

metrics_intervaledit

Specify the interval for reporting metrics to APM Server. The interval should be in seconds, or should include a time suffix.

To disable metrics reporting, set the interval to 0.

pool_sizeedit

Elastic APM uses a thread pool to send its data to APM Server.

This makes sure the agent doesn’t block the main thread any more than necessary.

If you have high load and get warnings about the buffer being full, increasing the worker pool size might help.

proxy_addressedit

An address to use as a proxy for the HTTP client.

Options available are:

There are also ENV version of these following the same pattern of putting ELASTIC_APM_ in front.

See Http.rb’s docs.

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 layman’s 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.

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 frame 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 collect stack traces for all spans. Set it to 0 to disable stack trace collection for all spans.

It has to be provided in duration format.

server_ca_certedit

The path to a custom CA certificate for connecting to APM Server.

stack_trace_limitedit

The maximum number of stack trace lines per span/error.

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.

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.

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.

Configuration formatsedit

Some options require a unit, either duration or size. These need to be provided in a specific format.

Duration formatedit

The duration format is used for options like timeouts. The unit is provided as suffix directly after the number, without any separation by whitespace.

Example: "5ms"

Supported units

Size formatedit

The size format is used for options like maximum buffer sizes. The unit is provided as suffix directly after the number, without any separation by whitespace.

Example: 10kb

Supported units:

we use the power-of-two sizing convention, e.g. 1 kilobyte == 1024 bytes