After reviewing some thread about server monitoring software I end up with a simple question:
Which of the server monitoring tools should I use for automatic detection of "abnormal" situations with recommendations on how to fix them?
I look for software that checks the system performance after installation and calculate some average load values (memory, CPU, etc). And when something happens (CPU load is increased to 20%) then it tries to detect a reason for this. If it is apache, it should check for access logs. If mysql, it should check mysql logs and tell me what happens. It this is because some user decodes a lot of images, I'd like to know which command is executed, when and user name. The same for disk usage, memory, number of processes, threads and so on.
Ideally, this software should periodically checks the system and report problems: errors in PHP error log, outdated packages, security vulnerabilities.
In other words, I'm looking for software that will keep my simple Debian/Apache/PHP/MySQL server without forcing me to monitor the charts every day.