ProcMeter3 is a program for monitoring the system status and other information and displaying it in a series of graphs or as text. Most of the information comes from the /proc filesystem (cpu usage, load average , processes information, memory usage, network traffic, interrupts etc.). Other information is available for other sources (date, time, email status, log file length, disk status etc.). The program is modular and highly configurable.
The main purpose of LoFiMo is, as the name states, to monitor log files. It does this in real time, i.e. shows the contents of log files as they are changing. The user can connect to LoFiMo with a Web browser or use the console for plain text output. When using a Web browser, the output can be formatted with cascading stylesheets, which the user can define. Thus, it is possible to highlight certain log entries with different colors and fonts. It is also possible to play sounds or execute commands (send an email, play sound with a custom player, etc.) when a log entry matches a filter. LoFiMo can parse Apache style log files and syslog style log files. Among others, there are filters that can parse iptables logs and merge multiple log lines of Postfix into a single one.
ICPLD (Internet Connection Performance Logging Daemon) is a connection monitor that sends ICMP requests to IP addresses of your choice and monitors if your machine has a working network connection. It logs failed attempts to reach the hosts, and will stamp a log as soon as a reply is received. It keeps track of when and for how long the connection was unavailable and records both total down time and each occasion of interrupted connection. It supports IPv6 and can execute a command whenever a connection goes up or down, which is useful for alerting users.
Log watcher is a PHP class that polls log files and takes newly added lines to send them to a given watcher email address. Although this class can be used to poll any type of log files, it was developed with the intention to overcome a limitation of the PHP error trapping system that is not able to capture certain types of errors during script execution, like script parsing errors or form file uploading failures. It is meant to be used from cron-like task schedulers to poll log files regularly. The email notification message can be composed from text templates. The message delivery function can be replaced by custom functions like the urgent mail function that can be faster for delivering critical messages.
FSHeal aims to be a general filesystem tool that can scan and report vital "defective" information about the filesystem like broken symlinks, forgotten backup files, and left-over object files, but also source files, documentation files, user documents, and so on. It will scan the filesystem without modifying anything and reporting all the data to a logfile specified by the user which can then be reviewed and actions taken accordingly.
RRDutil is a a tool to collect statistics (typically every 5 minutes) from multiple servers, store the values in RRD databases (using RRDtool), and plot out pretty graphs to a Web server on demand. The graph types shown include CPU, memory, disk (space and I/O), Apache, MySQL queries and query types, email, Web hits, and more.