Set Up Crons

Once implemented, it'll allow you to get alerts and metrics to help you solve errors, detect timeouts, and prevent disruptions to your service.

Requirements

• Use our getting started guide to install and configure the Sentry Ruby SDK (min v5.12.0) for your recurring job.
• Create and configure your first Monitor.

Job Monitoring

If you're using sidekiq-cron or sidekiq-scheduler, Sentry can automatically capture check-ins for all jobs that are scheduled to run periodically. To achieve this, you need to enable the corresponding Sentry plugin:

Sentry.init do |config|
  config.enabled_patches += [:sidekiq_cron]
  # or, for sidekiq-scheduler:
  config.enabled_patches += [:sidekiq_scheduler]
end

More generally, popular job frameworks such as ActiveJob and Sidekiq with a perform method can use the Sentry::Cron::MonitorCheckIns mixin module to automatically capture check-ins.

class ExampleJob < ApplicationJob
  include Sentry::Cron::MonitorCheckIns

  sentry_monitor_check_ins

  def perform(*args)
    # do stuff
  end
end

You can pass in optional attributes to sentry_monitor_check_ins as follows.

# slug defaults to the job class name
sentry_monitor_check_ins slug: 'custom_slug'

# define the monitor config with an interval
# the units supported are :year, :month, :week, :day, :hour, :minute
sentry_monitor_check_ins monitor_config: Sentry::Cron::MonitorConfig.from_interval(1, :minute)

# define the monitor config with a crontab
sentry_monitor_check_ins monitor_config: Sentry::Cron::MonitorConfig.from_crontab('5 * * * *')

Manual Setup

If you're using Clockwork or Whenever, you'll need to instrument your jobs manually.

Check-Ins (Recommended)

Check-in monitoring allows you to track a job's progress by completing two check-ins: one at the start of your job and another at the end of your job. This two-step process allows Sentry to notify you if your job didn't start when expected (missed) or if it exceeded its maximum runtime (failed).

check_in_id = Sentry.capture_check_in('<monitor-slug>', :in_progress)
# Execute your scheduled task here...
Sentry.capture_check_in('<monitor-slug>', :ok, check_in_id: check_in_id)

If your job execution fails, you can notify Sentry about the failure:

Sentry.capture_check_in('<monitor-slug>', :error, check_in_id: check_in_id)

Heartbeat

Heartbeat monitoring notifies Sentry of a job's status through one check-in. This setup will only notify you if your job didn't start when expected (missed). If you need to track a job to see if it exceeded its maximum runtime (failed), use check-ins instead.

Sentry.capture_check_in('<monitor-slug>', :ok)

If your job execution fails, you can notify Sentry about the failure:

Sentry.capture_check_in('<monitor-slug>', :error)

Upserting Cron Monitors

You can create and update your Monitors programmatically with code rather than creating and configuring them in Sentry.io.

First create a config object from either a crontab or an interval.

# Create a config from a crontab schedule (every 10 minutes)
monitor_config = Sentry::Cron::MonitorConfig.from_crontab(
  '5 * * * *',
  checkin_margin: 5, # Optional check-in margin in minutes
  max_runtime: 15, # Optional max runtime in minutes
  timezone: 'Europe/Vienna', # Optional timezone
)

# Create a config from an interval schedule (every 10 minutes)
monitor_config = Sentry::Cron::MonitorConfig.from_interval(
  10,
  :minute,
  checkin_margin: 5, # Optional check-in margin in minutes
  max_runtime: 15, # Optional max runtime in minutes
  timezone: 'Europe/Vienna', # Optional timezone
)

Then, use that config object during your check-ins.

# 🟡 Notify Sentry your job is running:
check_in_id = Sentry.capture_check_in(
  '<monitor-slug>',
  :in_progress,
  monitor_config: monitor_config
)

# Execute your scheduled task here...

# 🟢 Notify Sentry your job has completed successfully:
Sentry.capture_check_in(
  '<monitor-slug>',
  :ok,
  check_in_id: check_in_id,
  monitor_config: monitor_config
)`

Alerts

When your recurring job fails to check in (missed), runs beyond its configured maximum runtime (failed), or manually reports a failure, Sentry will create an error event with a tag to your monitor.

To receive alerts about these events:

1. Navigate to Alerts in the sidebar.
2. Create a new alert and select "Issues" under "Errors" as the alert type.
3. Configure your alert and define a filter match to use: The event's tags match {key} {match} {value}.

Example: The event's tags match monitor.slug equals my-monitor-slug-here

Learn more in Issue Alert Configuration.

Rate Limits

Crons imposes a rate limit on check-ins to prevent abuse and resource overuse. Specifically, you can only send a maximum of 6 check-ins per minute per existing monitor environment. This limit is enforced on a per-project basis, meaning that the rate limit applies collectively to all monitor environments within a given project. You can check if any of your check-ins are being dropped in the Usage Stats page.

To avoid dropped check-ins, it is crucial to manage and distribute your check-ins efficiently within the rate limits. This will help maintain accurate monitoring and ensure that all critical check-ins are captured and processed.