How to reduce false positives and frequent temperature alerts
Filed under: Data Center, environmental monitoring, SensorProbes, temperature monitoring
Previously, I wrote about managing the sensitivity of your motion detector to prevent or reduce false positives from normal environmental motion, while maintaining the security that the motion detector sensor provides. I thought I would elaborate on the subject by providing some tips on how to limit frequent alerts and false positives for any environmental monitoring sensor, like temperature.
As I mentioned before, the “continuous time to report,” or “rearm” as it is called on the SecurityProbe, are an excellent way to say, “Don’t alert me as soon as a sensor goes into a ‘warning’ or ‘critical’ status. However, if it has been in a ‘warning’ state for 30 seconds, let me know.”
Another way to limit how often – or how easily – your BitSight2 or SecurityProbe sends you Skype alerts or emails is to adjust the “reading offset” field, which can be found under each sensor’s advanced settings. The “reading offset” forces the sensor’s reading to move over or under a certainly value before generating an alarm. So basically, if your temperature upper “warning” threshold is set to 80 degrees and your “reading offset” is set to 2, and the current temperature is 79 degrees, then your SensorProbe will not alarm until the temperature drops another degree.
This prohibits the sensor from being right on the verge of a threshold and consistently bouncing between two statuses. You don’t want 20 emails in your inbox because the temperature in your data center is exactly on your threshold and wobbling back forth between “normal” and “warning.”
Another way of limiting alerts during off hours, maintenance windows or times when you are not really concerned with the readings breaching a threshold is to use the calendar feature. Please note that the calendar feature is available only on the SecurityProbe line of SensorProbes.
Block off times that you do not wish to receive alerts and the SecurityProbe will ignore the breached thresholds during those time frames. Perhaps you don’t want to receive alerts during the day, because people are always present and aware of the environmental conditions in the locations you are monitoring. However, maybe you want the temperature of your walk-in cooler monitored at night, when no one is in the building.
Whatever the reason, these are two great tips for better managing your alarms. This ensures that your alarms are more meaningful and so when you or you staff see an alert from your BitSight2 or SecurityProbe, you know it is time to act.
~ Jon Mills
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Help desk: How sensitive is your motion detector sensor?
Recently, I blogged about using the motion detector sensor to increase the security presence of your data center. Well, expanding on the topic, I thought I would answer one of those frequently asked questions I get from customers using the motion detector to beef up security. “How do I keep the motion sensor from being set off by very small movements?” The answer – you can adjust the sensitivity of the motion detector using the sensor status filter.
The sensor status filter allows you to enter a time delay that must occur before the sensor changes status, thus filtering out noise in the signal. This avoids unnecessary sending of notifications, as fluctuations can occur during normal working conditions.
To find this setting, go to the Motion Sensor Settings page of the web interface, and click on the sensor status filters button. Change the “Continuous time (secs) sensor is to report” field to some value other than zero. 1 second is a good place to start, but it all depends on your specific working conditions.
At any rate, increasing the continuous time to report field a bit can help keep you from getting false positives and give a little extra room for normal environmental shifts.
Stay tuned to the Ravica blog for more helpful environmental monitoring tips.
~ Jon Mills
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