Looking For Tools To Monitor Sql And Applications

I am looking for the right tools to do application monitoring.


I'm hoping to find one single tool that can do the entire job but if
it does not exist then a few monitoring apps would do as well.



I need the ability to do the standard things like testing for ping,
checking for windows services running and restarting them after some
threshold is met, and wmi.

Some of the more tricky things I need it to do are:


* Parse log files looking for specific error codes, and the ability to
set an alert only if it sees that error X times over some period of
time.

* Run custom slq queries like row counts and max values returned from
a query and if that condition is met X times over some period of
time.

* Run an external app that does its own custom testing and act on its
results, which could be to parse the result file from the app.



Keep in mind cost is not the isssue right now - so this can be
freeware to some type of enterprise solution that our company can use.
Does anyone know of any tools that you can point me towards?

Thanks...