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Sematext Alerts User Guide

Receiving Alerts when your software is misbehaving or underperforming is crucial for every developer. Good alerting practices include:

  • Alert Rules that detect Anomalies and notify when key performance indicators spike or drop
  • Criteria that trigger Alerts for monitored resources
  • Thresholds defined for Alerts when selected metrics reach certain severity levels
  • Notification channels through which the responsible team will be notified about the incident

Sematext Alerts help you address underlying issues before they affect user experience. There are three types of Alerts.

  • Threshold - Alerts that are based on classic thresholds. They are triggered when something crosses a pre-defined threshold.
  • Anomaly - Alerts based on statistical anomaly detection. They are triggered when values suddenly change and deviate from the baseline.
  • Heartbeat - Alerts triggered when something you are monitoring, like your servers, containers, or your applications, stops sending data to Sematext Cloud.

Threshold and Anomaly Alerts can be triggered for both Monitoring and Logs Apps, while Heartbeat Alerts are only available for Monitoring Apps.

Sematext lets you manage Alert Rules across your whole stack. You can use various notification channels to get alerted when critical issues occur so you can take action and resolve them. Our Alerts easily integrate with notification and chat software.

  • PagerDuty
  • OpsGenie
  • HipChat
  • Slack, and many more.

Default Alerts

As soon as an App is created, either for Logs or Monitoring, you will see several app-specific Alerts Rules created for you by default.

Default Alerts for a Logs App:

  • Anomaly Alerts for Error and Warning search queries

Default Alerts for a Monitoring App:

  • Metric Alert for Disk Usage
  • Heartbeat Alert if the Agent stops sending data to the Monitoring App
  • Metric Anomaly Alert for misbehaving Nodes

In this example which is an Elasticsearch Monitoring App, the Java usage threshold and Elasticsearch Node Anomalies are integration-specific default Alerts.

Sematext Cloud System Generated Alerts

You can view all the default and custom Alerts on the Alert Rules page. This is where you can toggle, edit or delete any existing Alerts.

Sematext Cloud Alerts Rules Window

Creating Alerts

Sematext Alerts can cover both complicated alerting scenarios with multiple rules for both Logs and Monitoring, as well as Events. A basic Alert Rule with an email or Slack notification is enough to cover elementary alerting needs.

Alerting on Logs

To create an Alert you need to run a search query and press Save Query/Alert Rule.

Create Alert Search Query

A Save Query window will open with the option to Enable Alert. When it's toggled, the Alert Type picker and Condition will expand, and the Notifications and Schedule tabs will be enabled. You'll see:

  • Alert Type, to choose either Threshold Alerts or Anomaly Alerts. For more information on alerting capabilities check alerts documentation pages.
  • Condition, to choose when the Alert will be triggered.
  • Ignore regularly occuring spikes and dips, where we look at historical data and try to decide if an alert fits the regular stream of spikes and dips in metrics. If it does, we won't interrupt you with notifications.

    Based on the filter combination we find all previous spikes and dips from the past. Split them into group-by values (+-5% we assume as the same), find LCM (least common multiple) in the groups. This means we're trying to include the current value into our LCM groups to check if it fits any of them or not. If it fits, we assume this is a regular event and ignore it.

Enable Alert Notification

  • Notification hook details with a default email notification hook used to send the message to your account. You can also add additional email addresses as well as other types of notification hooks.

Set Alert Notification Hooks

  • Schedule, to choose when the Alerts will notify you based on a period, schedule or time.

Press Save and you're done. Check out the integrations documentation for more information about alert notification hooks.

Alerting on Metrics

Monitoring Apps have metric-based Alerting. Metrics have both Threshold and Anomaly Alerts which can be created on a per-metric basis.

Sematext Cloud Metric Component Alerts

Monitoring Apps also have Heartbeat Alerts as part of their settings. You can find it in the App Settings dropdown menu. They are triggered when what you are monitoring, like your servers, containers, or your applications stop sending data to Sematext.

Sematext Cloud Metric Component Custom Alerts