Hi All,
I am in the process of evaluating Drools to use in a networks
& systems management project. Some of the initial use cases are listed
below.
Use Cases:
1.
Simple single parameter thresholds with configurable
warning and error levels.
2.
Simple multi parameter thresholds from one host with
configurable warning and error levels.
3.
Complex multi parameter thresholds from multiple hosts
with configurable warning and error levels.
4.
Complex time based multi parameter thresholds from
multiple hosts with configurable warning and error levels.
After reading about the Drools rules engine (Expert) and the
CEP (Fusion) it seems at a glance that it would be very useful in this
application. As I digging into use case 1 I am not sure Drools is actually going
to fit the bill as first thought.
Imagine a small network with 300 hosts each of which is
being polled for CPU data which can be massaged to produce an instantaneous CPU
Utilization which I want to check against some threshold, which can be
different for each host. I don’t see creating 300 rules to handle this
simple case as an ideal solution as I need to give control of the CPU
Utilization threshold to the teams who own the hosts. Thinking about how to
abstract that I imagine I could put the thresholds into a database and
rebuild/reload the rules as necessary but as the thresholds could change often
this seems like unnecessary overhead. I have moved on from that solution to the
idea that a threshold is an attribute of the parameter as name and value are
attributes. This allows me to attach the threshold value to the parameter
update and potentially have a Drools rule something like (not a working rule):
rule “test rule”
when
$param
: Parameter(name == someName) # comes from some map of params or something, not
sure yet.
$param(value
>= warningThreshold)
then
#
Fire warning alert
end
Where value and warningThreshold are members of the
Parameter object.
Having thought about this and discussed with some colleagues
we can not impose a ‘>=’ in the rule as some teams might what a
different set of comparators. Moving on to these new requirements I thought we
could have all the info encapsulated into the Parameter object as a set of
functions:
·
isInWarning
·
isInError
rule “test rule”
when
$param
: Parameter(name == someName) # comes from some map of params or something, not
sure yet.
$param.isInWarning()
then
#
Fire warning event
End
Questions:
·
Is the above possible in Drools?
·
What does Drools get me as my software is
already doing all the calculation and comparison work?
·
Is there a better way to handle this using
Drools?
Thanks for the reply’s
Glenn