monitoring tools

-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 It has been a while since I have had to seriously think about network/system/application monitoring and now I have got to look at it. Can anyone point me towards: 1. Serious documents on monitoring (i.e. not vendor whitepapers) 2. Open Source Tools that you use or would recommend (I know the obvious smokeping, mrtg, nagios). Thanks, - ---> Phil -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.7 (MingW32) iD4DBQFHJ5sZa2RfHGe2XK4RAj3bAJ4oNXS4XUfUiUz5pc8zeL4cdnCUBwCY06dP qN872ahrJT+fCX/+g0hrZw== =b5pJ -----END PGP SIGNATURE-----