Configuring Checks

In Hostchecks, 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. Hostchecks pricing plans are structured primarily around how many checks you can have in your account. You can create checks either in Hostchecks web interface or via 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. Hostchecks will display check names in the web interface, in email reports, and in 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

Hostchecks 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.

Note: if you use the "start" signal to measure job run times, then Grace Time also specifies the maximum allowed time gap between "start" and "success" signals. Whenever Hostchecks receives a "start" signal, it expects to receive a subsequent "success" signal within Grace Time. If the success signal does not arrive within the configured Grace Time, Hostchecks will mark the check as failed and send out alerts.

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 the 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 the 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 Hostchecks 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 Start Keywords, Success Keywords, or Failure Keywords, Hostchecks will assume it to be a start, a success, or a failure signal respectively. This is useful if, for example, your backup software sends an email after each backup run with a different subject line depending on success or failure.
• Filter by keywords in the message body. Same as the previous option, but looks for the keywords in the email message body. Supports both plain text and HTML email messages.
• 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": Hostchecks will ignore all incoming pings until you explicitly resume the check.