Starting in Grafana 3.x the KairosDB data source is no longer included out of the box.
But it is easy to install this plugin!
Either clone this repo into your grafana plugins directory (default /var/lib/grafana/plugins if your installing grafana with package). Then run grunt to compile typescript. Restart grafana-server and the plugin should be automatically detected and used.
git clone https://github.com/grafana/kairosdb-datasource npm install grunt sudo service grafana-server restart
Clone into a directory of your choice
Then edit your grafana.ini config file (Default location is at /etc/grafana/grafana.ini) and add this:
[plugin.kairosdb] path = /home/your/clone/dir/datasource-plugin-kairosdb
Note that if you clone it into the grafana plugins directory you do not need to add the above config option. That is only if you want to place the plugin in a directory outside the standard plugins directory. Be aware that grafana-server needs read access to the directory.