[evla-sw-discuss] severity of alerts

[Bryan Butler]

all,

we've gotten to the point where we need to define a severity level for 
alerts.  the operators need this in order to tell the importance level 
of them as they arrive on the checker screen.

i propose that we define an integer alert level from 0 to 5, with 0 
being the highest importance (issues of safety) and 5 being 
informational only.  if somebody can make a case for more granularity 
(do we need 10 levels?), that's fine.

the engineers will be going over each MIB and its monitor points and 
assigning this severity code to its alerts.  pat van buskirk is going to 
do the leg work of pestering the engineers on this.

in addition to a severity level, an "action" for the operator has to be 
defined for each of these alerts.  this would be similar to the page at: 
http://www.vla.nrao.edu/operators/alarms/ for the VLA.

once they have them defined, then we need to support them.  there are 
two ways that i see to do this:
  1 - each MIB has coded into it these severity levels, just as it
      has coded into it the levels at which alerts are triggered, and
      when the alert is sent out, the severity code goes out with it;
  2 - there is a lookup table which checker uses, given the MIB and
      the monitor point/alert, to assign severity, and any program
      that receives the alerts can use that lookup table to retrieve
      the severity level.

the advantage to 1 is that it keeps the information closest to the MIB. 
  it also saves the "management" software upstream.  the disadvantage is 
that if you decide to change anything you have to modify all of those 
MIB images.  the advantage to 2 is that you avoid that MIB image 
modification, and can centralize everything (in a database or similar). 
  another advantage is that you can also include the "action" in this 
database, as well as flagging information.  since you are going to need 
these other things there, you might as well add a column for severity.

i prefer the lookup table/database, but would like to hear other opinions.

	-bryan