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 Elixir SDK (min v10.2.0) for your recurring job.
• Create and configure your first monitor.

Job Monitoring

If you're using Oban or Quantum, 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:

config :sentry,
  integrations: [
    oban: [cron: [enabled: true]],
    # Or for Quantum:
    quantum: [cron: [enabled: true]],
  ]

Manual Setup

If you're using another library or a custom solution for scheduling jobs, you'll need to instrument those 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).

{:ok, check_in_id} = Sentry.capture_check_in(status: :in_progress, monitor_slug: "<monitor-slug>")

# Execute your scheduled task here
my_scheduled_job()

Sentry.capture_check_in(check_in_id: check_in_id, status: :ok, monitor_slug: "<monitor-slug>")

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

Sentry.capture_check_in(check_in_id: check_in_id, status: :error, monitor_slug: "<monitor-slug>")

Heartbeats

Heartbeat monitoring notifies Sentry of a job's status through a single 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(status: :ok, monitor_slug: "<monitor-slug>")

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

Sentry.capture_check_in(status: :error, monitor_slug: "<monitor-slug>")

Upserting Cron Monitors

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

To do that, you need to pass a :monitor_config set of options to Sentry.capture_check_in/3:

# Create a config from a crontab schedule (every 10 minutes)
monitor_config = [
  schedule: [
    type: :crontab,
    value: "5 * * * *",
  ],
  checkin_margin: 5, # Optional check-in margin in minutes
  max_runtime: 15, # Optional max runtime in minutes
  timezone: "Europe/Vienna", # Optional timezone
]

# Alternatively, create a config from an interval schedule (every 10 minutes in this case):
monitor_config = [
  schedule: [
    type: :interval,
    unit: :minute,
    value: 10
  ],
  checkin_margin: 5, # Optional check-in margin in minutes
  max_runtime: 15, # Optional max runtime in minutes
  timezone: "Europe/Vienna", # Optional timezone
]

# Notify Sentry your job is running:
{:ok, check_in_id} =
  Sentry.capture_check_in(
    status: :in_progress,
    monitor_slug: "<monitor-slug>",
    monitor_config: monitor_config
  )

# Execute your job:
execute_job()

# Notify Sentry your job has completed successfully:
Sentry.capture_check_in(
  status: :ok,
  check_in_id: check_in_id,
  monitor_slug: "<monitor-slug>",
  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 connected 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.