Introducing Watchdog Custom Alerts: Monitor Anything on Your Servers, For Free

We’re pleased to now introduce Watchdog Custom Alerts, part of our Watchdog 2.0 release. Where Watchdog’s Essential Alerts™ automatically monitor vital server metrics, Custom Alerts cover everything else. With Custom Alerts, the possibilities for monitoring key indicators for maintaining uptime just became limitless.

Watchdog, our free-forever server monitor, already notifies you of all your systems’ vitals and health metrics with built-in zero-config Essential Alerts™. These alert on CPU, swap space, memory, ulimits, VM steal time and more.

“Custom Alerts can be configured to monitor apps metrics, IP blacklists, cron jobs — any arbitrary thing,” says Keilan Jackson, our senior engineer. “It’s also easy to migrate your Nagios scripts to instead utilize Watchdog Custom Alerts.”

With Custom Alerts, Watchdog detects changes in a directory and sends an alert when a file is created or removed from the directory. So when a file is created, an alert will be created with the filename of the file as the title, and the contents of the file as the body. When the file is removed, the alert will be resolved.

How We’re Using Watchdog Custom Alerts to Improve Blue Matador’s Uptime

Watchdog uses Elasticsearch in our stack to provide fast and reliable search results for Lumberjack log entries. One known issue with Elasticsearch is that performance can degrade when there are too many indices.

Fortunately, one of the Watchdog Custom Alerts we use gives us peace of mind, is just a short script running on a cron job that simply checks if our elasticsearch clusters have grown too big. Watchdog Custom Alerts allow us to simply put a file in a directory to trigger an alert on anything, and remove it when the issue is resolved.

Here is the simple script we use to check for Elasticsearch indices on an Ubuntu server:


SIZE=$(curl -s "http://localhost:9200/_cat/indices" | wc -l)


if [[ "$SIZE" -gt 10000 ]]; then

    echo "We have too many indices. Currently at $SIZE" | tee $FILE


    rm -f $FILE


This runs on a cron job every minute and is a quick and simple way to set up a Custom Alert and augment the system vital monitoring that Watchdog already provides in our Elasticsearch cluster.

Try Watchdog Custom Alerts Now

We made our Watchdog product free forever because we want to help system admins get ahead of the firefighting curve. Our founders spent years doing on-call DevOps monitoring, day and night. So we get the frustration of fighting fires all the time, always balancing the need to fix production, add more monitoring, and do more of the “real” DevOps work you were hired to do.

You can install Watchdog on your servers right now by creating a free Blue Matador account and and installing on your Linux or Windows servers. No credit card is needed because we really mean it when we say Watchdog is free forever.

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Blue Matador Staff

Author Bio

Blue Matador is the AI-powered DevOps monitoring platform that solves the "Franken-monitor" effect, enabling organizations to have all their monitoring tools in one place.

What is Blue Matador?

Blue Matador is the AI-powered DevOps monitoring platform that provides real-time, predictive alerts that help your team decrease downtime and increase customer confidence in your brand. Learn more

Our Monitoring Products

Watchdog is the free server monitor that sends you and your team proactive system vitals alerts, proactively notifying you of all the metrics you need to know to prevent downtime. Install for free

Lumberjack is the AI-powered centralized log management tool that proactively warns your DevOps team of impending server and app issues that affect uptime. Try free for 14 days