What monitoring system to install?

Question

linux

advise which monitoring system to install, a simple vps 1GB of RAM, with attendance of 100-200 does not stand up, 90% of memory is used, which affects system performance and the site takes a long time to load. Set monit
check system $HOST
if loadavg (1min) > 4 then alert
if loadavg (5min) > 2 then alert
if cpu usage > 75% for 10 cycles then alert
if cpu usage > 85% for 10 cycles then restart
if memory usage > 75% then alert
if memory usage > 85% then restart
if swap usage > 25% then alert
but the condition
if memory usage > 85% then restart - doesn't work in
general I want the server to reboot at least for now

Answer 1

Better look at which process is loading the percent and start optimizing it
, and for reboot the correct command
is if cpu usage > 85% for 10 cycles then exec /sbin/reboot
but this is a crutch

Answer 2

Monitor here. monit-it.ru
And third-party monitoring and modules from nagios can eat
And even fix errors.
Cheap, cheerful, simple. does not load the server