Heartbeat

Heartbeat is a simple way to check a process's vital signs. Use it instead of Monit, Pingdom, Uptime Robot, or any combination thereof.

It's intended to be used in simple applications where full-scale process monitoring is overkill.

Usage

Making a new Heartbeat is easy. Just open up a terminal and type:

curl http://heartbeat.alexose.com/[email protected]/60

This will create a new heartbeat that will alert "[email protected]" in 60 seconds. You can postpone this alert by running the same command again, or you can stop it altogether by sending a cancellation:

curl http://heartbeat.alexose.com/[email protected]/cancel

Heartbeat handles these nonstandard URLs and does not require them to be encoded in any special way.

Examples

It's often useful to know whether a machine has lost power or internet connectivity. An easy to monitor this might be to add a Heartbeat to your crontab. From the terminal, type:

(crontab -l ; echo "* * * * * curl http://heartbeat.alexose.com/[email protected]/120") |   crontab -

This updates the Heartbeat every 60 seconds. If it fails to update, you'll receive an alert after 120 seconds.

Advanced

Note that each request is tracked by a combination of your IP and User-Agent, so there's no need for unique IDs or tags. If you need multiple heartbeats, simply use a different User-Agent:

curl -A "process one" http://hearbeat.server/[email protected]/30
curl -A "process two" http://hearbeat.server/[email protected]/30

Heartbeat can also alert you if a particular value is out of range:

curl http://heartbeat.server/[email protected]/30/70/60/80  # in range
curl http://heartbeat.server/[email protected]/30/72        # in range
curl http://heartbeat.server/[email protected]/30/59        # out of range

Installation

If you'd like to run it on your own machine, just npm checkout heartbeat-server.

npm install heartbeat-server
node heartbeat-server app.js [port]

Security

There is none.

Redundancy

Nope!

Rate Limiting

By default, each IP is only allowed to send 20 alerts per day.