healthchecks/templates/docs/configuring_checks.md

Configuring Checks

In SITE_NAME, a Check represents a single service you want to monitor. For example, when monitoring cron jobs, you would create a separate check for each cron job to be monitored. SITE_NAME pricing plans are structured primarily around how many checks you can have in your account. You can create checks either in SITE_NAME web interface or by calling Management API.

Name, Tags, Description

Describe each check using an optional name, tags, and description fields.

• Name: names are optional, but it is a good idea to set them. Good naming becomes especially important as you add more checks to the account. SITE_NAME will display check names in the web interface, in email reports, and notifications.
• Tags: a space-separated list of optional labels. Use tags to organize and group checks within a project. You can tag checks by the environment (prod, staging, dev, etc.) or by role (www, db, worker, etc.) or using any other system.
• Description: a free-form text field with any related information for your team or your future self. Describe the cron job's role, who set it up, what to do in case of failures, where to look for additional information.

Simple Schedules

SITE_NAME supports two types of schedules: Simple and Cron. Use Simple schedules for monitoring processes that you expect to run at relatively regular time intervals: once an hour, once a day, once a week.

For the simple schedules, you can configure two parameters, Period and Grace Time.

• Period is the expected time between pings.
• Grace Time is the additional time to wait before sending an alert when a check is late. Use this parameter to account for small, expected deviations in job execution times.

Cron Schedules

Use "cron" for monitoring processes with more complex schedules. This monitoring mode ensures that jobs run at the correct time, and not just at correct time intervals.

You will need to specify Cron Expression, Server's Time Zone, and Grace Time.

• Cron Expression is the cron expression you specified in the crontab.
• Server's Time Zone is the timezone of your server. The cron daemon typically uses system's local time. If the machine is not using the UTC timezone, you need to specify it here.
• Grace Time, same as for simple schedules, is how long to wait before sending an alert for a late check.

Filtering Rules

In the "Filtering Rules" dialog, you can control several advanced aspects of how SITE_NAME handles incoming pings for a particular check.

• Allowed request methods for HTTP requests. You can require the ping requests to use HTTP POST. Use the "Only POST" option if you run into issues of preview bots hitting the ping URLs when you send them in email or post them in chat.
• Filter by keywords in the Subject line. When pinging via email, look for specific keywords in the subject line. If the subject line contains any of the keywords listed in Success Keywords, SITE_NAME will assume it to be a success signal. Likewise, if it contains any of the keywords listed in Failure Keywords, SITE_NAME will treat it as an explicit failure signal. For example, this is useful if your backup software sends an email after each backup run with a different subject line depending on success or failure.
• Pinging a Paused Check. Normally, when you ping a paused check, it leaves the paused state and goes into the "up" state (or the "down" state in case of a failure signal). You can change this behavior by selecting the "Ignore the ping, stay in the paused state" option. With this option selected, the paused state becomes "sticky": SITE_NAME will ignore all incoming pings until you explicitly resume the check.