Generating Graphs

Collectd is thus superior to serverstats when it comes to extensibility. However, anyone wanting to display basic data quickly in a web interface will be happy with serverstats. A functional configuration of Apache is already located in the doc directory:

/usr/share/doc/serverstats# cp examples/apache.conf /etc/apache2/sites-available/serverstats.conf
# a2ensite serverstats.conf
# service apache2 reload

A cron job automatically creates the rrd data in /var/lib/serverstats/rrd every minute:

$ ls /var/lib/serverstats/rrd/
apache_localhost.rrd cpu.rrd disk_sda.rrd load.rrd memory.rrd traffic_proc_eth0.rrd users.rrd

After the Apache configuration is activated, the graphs are available immediately in the web interface, as shown in Figure 3.

Figure 3: Only a few steps are required in serverstats to make graphs.

Collectd does not provide its own interface for creating graphs. However, plenty of options are available for generating graphs from rrd data. As a web interface, collectd-web makes a solid impression (Figure 4). The best approach is to install it directly from the Git repository (Listing 8).

Figure 4: Collectd-web is an appealing web interface for collectd.

Collectd also stores its data in the /var directory; /var/lib/collectd/rrd has a subdirectory for each enabled plugin. Those not wanting to set up a web server for viewing graphs on their production system can either copy the data to another system or operate collectd as a client server. The network plugin allows data transfer to a central collectd server via UDP connections.

Conclusions

The tools described in this article will help you get better performance from your systems. Once you learn the basics, you'll find many ways to put these performance tools to work.