[OSM-dev] [OSM-talk] Tile and dev down

Raphael Jacquot sxpert at esitcom.org
Mon Sep 25 09:00:36 BST 2006


Nick Hill wrote:
> Hello Etienne
> 
> If there is a local power failure, given the upstream network 
> infrastructure will not be on UPS, we will inevitably experience some 
> service outage. If we can ensure the servers come back up in the event 
> of power interruption, all should be well.
> 
> There are some other aspects of UPS which come into the equation; 
> potential data loss, potential UPS failures and increased energy demand 
> through UPS systems.
> 
> Data loss is the biggest concern. UPS can help, but this is really best 
> addressed through backup strategy, as there are so many potential points 
> of failure which could lead to data loss, not related to power source 
> failure.

properly set up UPS will allow for orderly shutdown of the boxes, thus 
preventing potential database corruption.
good UPSs have a network connection and can be handled by munin (snmp), 
we have that type at work

> Potential UPS failure; If the UPS failed, all systems will be offline 
> until someone can bypass the UPS. UPSs also need periodic maintenance 
> and replacement of lead-acid accumulators. This brings in disposal 
> issues and environmental issues.

a good UPS will have it's default failure mode to bridge the power to 
the box, removing itself from the equation, and sending a message (snmp 
trap) or failing to send a message (watchdog timer) to the munin 
management console (which can also send warning mails), thus telling the 
interested people to look into the failure

> Increased energy demand. UPS systems loose some supply energy. 
> Currently, this financial cost would be externalised from the OSM 
> project as we don't (currently) pay for the direct electricity and 
> electricity used for air conditioning cooling. However, OSM servers are 
> built with environmental consideration and use recycled materials where 
> appropriate. OSM can therefore claim to be an environmentally conscious 
> project. I personally try to live with a small ecological footprint, so 
> I prefer options which don't involve energy and material consumption.

ah well...




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