Cron Monitoring Setup Guide

How to Create a Cron Monitor

There are three common ways to create cron monitors.

1. Install the CronitorCLI to automatically add monitoring to your crontab files.

   If you are monitoring cron jobs on Linux, BSD or MacOS our CLI will detect the crontabs on your system, and will walk you through adding monitoring as desired. It will automatically create the monitors and make the required modifications to your crontab files.

2. Use the web dashboard to create individual monitors.

   Our web dashboard is an easy to use interface, and creating new monitors can be done quickly by anyone with a Cronitor account.

3. Integrate with our Monitor API to programatically create monitors.

   For more advanced use cases, such as adding Cronitor to provisioning or deployment scripts, we offer an easy to use REST API as well as open-source API clients for many popular languages.

How to Configure Alert Recipients

Cronitor can send alerts via many different channels, including: Email, Slack, PagerDuty, Microsoft Teams, SMS, webhooks and more.

Notification lists are configurable sets of channels that are attached to your monitors. When a monitor fails or recovers, an alert will be sent to every channel/recipient on the attached list. You can create or modify a list from the Notification Lists section of your settings page.

• Dashboard
• Monitor API

In the monitor's edit form locate the Alert Receipients panel. You may choose to add a notification list or add channels/recipients directly (or both).

Specify alert recipients adding a notifications object to your monitor JSON as shown below. Notification lists are attached using the template key. For complete list of options see our API docs.

curl -X POST https://cronitor.io/v3/monitors -u <API-KEY>: -d '{
    "name": "Database Backup",
    "type": "cron",
    "rules": [
    {
    "rule_type": "not_on_schedule",
    "value": "0 */3 * * 1-5"
    },
    ],
    notifications: {
    templates: ['devops-emergency'],
    slack: ['https://hooks.slack.com/2af3bvbnjwg9882']
    phone: ['+1555-555-5555']
    }

    }' -H "Content-Type: application/json"
            

Tip: When your Cronitor account is created a list named "Default" will automatically be created, and your email address will be added to it. When no list is specified the default list will be used.

How to Customize Duration Alerts

Cronitor uses the performance history of your job to detect anomalies in runtime. Our prediction algorithm grows more precise as we learn more about your job performance but it won't work perfectly for every job.

If you are receiving Running longer than expected alerts earlier than you would like, you can set a threshold duration for the job:

• Dashboard
• Monitor API

In the monitor's edit form locate the Alert Preferences panel and select Alert if this job runs longer than.

Specify a duration alert threshold by adding a ran_longer_than rule along with the not_on_schedule rule.

curl -X POST https://cronitor.io/v3/monitors -u <API-KEY>: -d '{
"name": "Database Backup",
"type": "cron",
"rules": [
{
    "rule_type": "not_on_schedule",
    "value": "0 */3 * * 1-5"
},
{
    "rule_type": "ran_longer_than",
    "value": 5,
    "time_unit": "minutes"
},

]
}' -H "Content-Type: application/json"
            

Nota Bene: With less data available on a new monitor we use a wider implied grace period and we will not send Running longer than expected alerts until the job has completed successfully at least once.

How to Customize Failure Tolerance Alerts

By default Cronitor will alert you every time we detect a problem. If you can tolerate a few failures, and do not wish be alerted each time, you can set the failure tolerance threshold of your monitor. You will be sent an alert when the number of consecutive failures exceededs the threshold.

• Dashboard
• Monitor API

In the monitor's edit form locate the Alert Preferences panel and select Failure Tolerance. Choose "Only send an alert if there is a persistent problem". Set the failure tolerance as desired.

Specify failure tolerance by adding the key tolerated_failures to your monitor's JSON object. The value is the threhold number.

curl -X POST https://cronitor.io/v3/monitors -u <API-KEY>: -d '{
"name": "Database Backup",
"type": "cron",
"tolerated_failures": 5,
"rules": [
{
    "rule_type": "not_on_schedule",
    "value": "0 */3 * * 1-5"
}
]
}' -H "Content-Type: application/json"
            

Adding Cronitor to Your Cron Jobs

For Cronitor to alert you when something goes wrong with your job a small amount of integration work is required to tell Cronitor when your job runs and completes or fails.

If you are monitoring traditional cron jobs the easiest way to do this the CronitorCLI. Running cronitor discover will add the integration for you automatically.

If you do not want to install the CLI, or you are not using crontab, you can integrate with Cronitor by instrumenting HTTP pings that correspond to the job running and completing. This can be done with curl as in the example below, or any http library. Cronitor's SDKs make it easy to integrate Cronitor with a number of popular languages.

# m h dom mon dow   command

0 1 * * * cronitor exec d3x0c1 /path/to/mysqlbackup.sh

# m h dom mon dow   command

0 1 * * * CRONITOR_ID=d3x0c1 cronitor /path/to/mysqlbackup.sh

# m h dom mon dow   command

0 1 * * * curl https://cronitor.link/d3x0c1/run -m 10 ;  /path/to/mysqlbackup.sh && 
curl https://cronitor.link/d3x0c1/complete -m 10

#!/usr/bin/env bash
cronitor ping d3x0c1 --run
/path/to/do_things.sh
cronitor ping d3x0c1 --complete

#!/usr/bin/env bash
curl https://cronitor.link/d3x0c1/run -m 10 || true
/path/to/do_things.sh
curl https://cronitor.link/d3x0c1/complete -m 10 || true

import requests
requests.get(
   'https://cronitor.link/d3x0c1/run',
   timeout=10
)

# Application Code Here

requests.get(
   'https://cronitor.link/d3x0c1/complete',
   timeout=10
)

from urllib2 import urlopen
try:
  urlopen('https://cronitor.link/d3x0c1/run', timeout=10)
except Exception:
    pass

# Application Code Here
try:
  urlopen('https://cronitor.link/d3x0c1/complete', timeout=10)
except Exception:
    pass

from urllib2 import urlopen
try:
  # Application Code Here
except Exception e:
    try:
      urlopen('https://cronitor.link/d3x0c1/fail?msg=' + e, timeout=10)
    except Exception:
      pass

require 'open-uri'
open(
   'https://cronitor.link/d3x0c1/run',
   :read_timeout=>10
)

# Application Code Here

open(
   'https://cronitor.link/d3x0c1/complete',
   :read_timeout=>10
)

require 'net/http'
begin
    Net::HTTP.get(URI.parse('https://cronitor.link/d3x0c1/run'))
rescue Exception => e
end

# Application Code Here

begin
    Net::HTTP.get(URI.parse('https://cronitor.link/d3x0c1/complete'))
rescue Exception => e
end

file_get_contents('https://cronitor.link/d3x0c1/run');
# Application Code Here
file_get_contents('https://cronitor.link/d3x0c1/complete');

$curl = curl_init();
curl_setopt_array($curl, array(
  CURLOPT_URL => 'https://cronitor.link/d3x0c1/run',
  CURLOPT_TIMEOUT => 10,
));
curl_exec($curl);

# Application Code Here

$curl = curl_init();
curl_setopt_array($curl, array(
CURLOPT_URL => 'https://cronitor.link/d3x0c1/complete',
CURLOPT_TIMEOUT => 10,
));
curl_exec($curl);

Tip:Our Cron Integration Guide has more examples and an overview of our Ping API.

Frequently Asked Questions

• What if my cron job starts after a random delay, like anacron?

  If you don't expect your job to start immediately at the scheduled time, expand the grace time on your monitor. Ensure your grace period exceeds any intentional or expected delay.

• How do I determine my server timezone?

  On Linux and MacOS, use timedatectl or date to determine the current timezone locale. On Windows, use tzutil /g. Timezones can be set per monitor, and an account-wide default is available on the account settings page.