Methodologies and systems for detecting an anomaly in a flow of data or data stream are described herein. To detect an anomaly, an anomaly detection server may create a baseline based on historical or other known non-anomalous data within the data stream. The anomaly detection server then generates one or more test values based on current data in the data stream, and compares the test value(s) to the baseline to determine whether they vary by more than a predetermined amount. If the deviation exceeds the predetermined amount, an alarm is triggered. The anomaly detection server may continually adjust the baseline based on the current data in the data stream, and may renormalize the baseline periodically if desired or necessary.