Types of anomalous behavior
Summarize
Summary of Types of Anomalous Behavior
Anomalous behavior in a configuration item (CI) or service can signify critical issues, such as a spike in message frequency. The system monitors log streams to establish baseline behavior patterns over various time periods (hourly, daily, weekly, or unlimited). Any deviation from these baselines is classified as anomalous behavior.
Show less
Key Features
- Log Property Types:
- Pattern: Repeating values or rates in text, time, or relationships.
- Meter: Numeric or text values such as status codes or actions.
- Gauge: Continuously reported numerical values representing resource consumption (e.g., CPU or memory usage).
- Anomaly Card: Displays anomalous activity with a blue line indicating recent anomalies and shaded areas showing expected behavior. Different colors represent data from previous periods for comparison.
Key Outcomes
Understanding the types of anomalies can help in identifying and addressing issues promptly. The types of anomalies include:
- New Behavior: Unseen patterns that trigger alerts without charts.
- Signal Dead: Lack of data from a source for over five minutes.
- Signal Alive: Resumption of data from previously inactive sources.
- Above/Below Average: Deviations from expected baseline behavior.
- Baseline Reference Change: Increases or decreases in log properties compared to established baselines.
- Severity and Keyword Alerts: Increased volume of specific severity levels or keywords.
Anomalous behavior in a CI or a service can indicate an important issue. For example, a spike in the frequency or number of messages of a particular type can indicate a problem.
Understanding anomalies
To build models of expected behavior, the system monitors the log stream to learn baselines for patterns, metrics, and gauges over various time periods. Time periods can be hourly, daily, weekly, or unlimited. Behavior that departs from the learned models is considered anomalous behavior.
Types of log property
- Pattern
- A pattern is a value or rate that repeats, whether in text, time, or relationships.
- Meter
- A meter property is a numeric or text value. For example, a status code, a response code, an action, or a pattern.
- Gauge
- A gauge property has a numerical value that is reported continuously. Gauge properties represent operations that consume resources. For example, CPU usage, memory usage, or response time.
How anomalies appear in the Service Operations Workspace
- The blue line shows the recent anomalous activity.
- On some charts, the lightly shaded area indicates the expected (learned
baseline) behavior.
A peach-shaded area represents the baseline values for the same hour one day earlier. A pink-shaded area shows the values for the same period in the previous week.
- Click the information icon to see how the anomaly was identified:
.
Kinds of anomalies
| Behavior | Description |
|---|---|
| New behavior | A pattern that has not ever been seen. The New Behavior alert type does not display a chart. |
| Signal dead/Stopped appearing | All pattern or log data from a source has stopped. There has been no signal for at least five minutes. |
| Signal alive/Appearing again | A pattern or log data from a "dead" source is appearing again. For a baseline of one hour, a pattern is "dead" if it appears less than once per minute. |
| Anomaly above average or below average | Activity that deviates from expected baseline behavior for pattern or meter or gauge metrics, such as keywords metrics or severity metrics. |
| Baseline reference increase or decrease | An increase or decrease in the value or volume of a log property as compared to the one-hour or one-week baseline. |
| Correlation of severity and keyword alerts | An increase in the volume of a severity level or keyword. |