Short bio: Computer Scientist, FOSS supporter (read more)
Tux Machines (TM)-specific
A website or network administrator relies on server/network monitoring software that can continuously keep an eye on the system and can detect slow or faulty components. These monitoring tools can automatically send updates or activate backups in case of outages caused by server crashes or overloads, network connections and other factors. For instance, to find out the status of a web server, monitoring software may occasionally send an HTTP request to fetch a page. For email servers, a test message might be dispatched through SMTP and brought back by IMAP or POP3. In the event of status request failures, the monitoring software may send an alarm message to sysadmin, turn on failover systems to eliminate the problematic server from duty until it can be fixed, or do other imperative actions.
For those of you who are looking for monitoring tools that can handle small to large-scale infrastructures, here is a list of some of the best open-source server/network monitoring software that you can use for free: