Note that keeping them separate has a benefit that when your 'Visualization' portal is down, your 'Alerting' systems are unaffected (and vice versa). Collectd,

Note that keeping them separate has a benefit that when your 'Visualization' portal is down, your 'Alerting' systems are unaffected (and vice versa). Collectd, telegraf. etc, can be configured to send the same metrics to your favorite TSDB and Alerting system (like riemann) in parallel.