Need to monitor Linux server performance? Try these built-in command and a few add-on tools. Most Linux distributions are equipped with tons of monitoring. These tools provide metrics which can be used to get information about system activities. You can use these tools to find the possible causes of a performance problem. The commands discussed below are some of the most basic commands when it comes to system analysis and debugging server issues such as:
- Finding out bottlenecks.
- Disk (storage) bottlenecks.
- CPU and memory bottlenecks.
- Network bottlenecks.
The ss command is used to dump socket statistics. It allows showing information similar to netstat command. It can display more TCP and state information than other tools. It is a new, incredibly useful and faster (as compare to netstat) tool for tracking TCP connections and sockets. SS can provide information about:
- All TCP sockets.
- All UDP sockets.
- All established ssh / ftp / http / https connections.
- All local processes connected to X server.
- All the tcp sockets in state FIN-WAIT-1 and much more.
The round-robin database tool aims to handle time-series data like network bandwidth, temperatures, CPU load etc. The data gets stored in round-robin database so that system storage footprint remains constant over time. Lighttpd comes with mod_rrdtool to monitor the server load and other details. This is useful for debugging and tuning lighttpd / fastcgi server performance.
tail is one of the best tool to view log files in a real time (tail -f /path/to/log.file). The program MultiTail lets you view one or multiple files like the original tail program. The difference is that it creates multiple windows on your console (with ncurses). This is one of those dream come true program for UNIX sys admin job. You can browse through several log files at once and do various operations like search for errors and much more.
I’ve already written about Linux process accounting under Linux ( see how to keep a detailed audit trail of what’s being done on your Linux systems). You can easily setup process accounting under FreeBSD. This tutorial expalins how to enable and utilizing FreeBSD process accounting including many other useful options are explained to keep track of system resources used, and their allocation among users.
The convenience and reliability that monitoring programs offer system administrators is astounding. Whether at home, commuting, or on vacation, admins can continuously monitor their networks, learning of issues long before they become catastrophes.
Nagios, the most popular open source solution for system and network monitoring, is extremely robust, but it’s also intensely complex.
Nagios is free, open source host, service and network monitoring services. Nagios provides an extensible framework, that can monitor pretty much anything using plugins.
