Real Time Monitoring of DCE

[DCIM_Support]

This question was originally posted on DCIM Support by Roxan Grace on 2019-01-30

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Hi Team,

We have a DCE in our office and its currently monitoring our UPS. What we notice is, some alarm are not being picked-up by the UPS. Like the fluctuation that cause the UPS to go on battery mode for several seconds, like 5-10 seconds. Also, during our genset operation, the transfer from normal-to-UPS power and vice versa, that cause the UPS to battery mode for about 20 seconds, is not picked up by DCE. No alarm has been registered on the DCE dashboard.

My question is, how real time is our DCE? Is it true that there are alarms that DCE can't detect because of time? Thank you.

(CID:138811205)

[DCIM_Support · Accepted solution]

This answer was originally posted on DCIM Support by Cory McDonald on 2019-01-30

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Roxan Grace,

DCE works by polling the devices.  The default polling interval is 5 minutes, but can be defined to be different within the Device Menu > SNMP Device Community Settings > Device Scan Settings.

APC (NMC) devices have the ability to utilize priority scanning.  Priority scanning takes place when an APC device has an active alarm.  An SNMP trap will be sent to the DCE server that will move the device scan towards the top of the queue.  DCE will then reach out to the device (SNMP) within a short period of time to check the device for what alarm may be active.  ModbusTCP devices do not have priority scanning as they work strictly on the polling interval and do not have a function similar to an SNMPtrap.

Additional information on priority scanning: 

https://www.apc.com/us/en/faqs/FA271584/

DCE does not take the trap and pull the error from it to add to the DCE alarm history.  It utilizes the SNMP scan from the priority scanning.  If an alarm is active when the priority scanning takes place it will then show the alarm within DCE.

It depends on the load on your server (number of devices, polling intervals, amount of sensors, surveillance, etc.) on how fast priority scanning takes place.  Usually it will take place within 30 seconds of an alarm going active on the device.

Here is an example of how this would work with your short time-frame alarms:

UPS on battery.

UPS NMC sends SNMPtrap to DCE (via priority scanning)

DCE recieves priority scanning & queues an SNMP scan.

12:00:20 - UPS no longer on battery.

DCE scans the device, but no alarm is active.

If the alarm stays active long enough, it would occur more like this:

UPS on battery.

UPS NMC sends SNMPtrap to DCE (via priority scanning)

DCE receives priority scanning & queues an SNMP scan.

DCE scans the device and sees the active alarm.

UPS no longer on battery.

Kind Regards,

Cory

(CID:138811215)

[DCIM_Support]

This comment was originally posted on DCIM Support by Roxan Grace on 2019-01-30

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Hi Cory,

Thank you very much for clarifying this one. I do now understand how the DCE processes the alarm notification. I will now have to check the scanning interval set to each of our devices and will utilize the priority scanning.

Thank you and Best Regards,

Roxan

(CID:138811262)

[DCIM_Support]

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