Since metrics on dropped packets are counters, the alerts should use
the rate() function. This change also fixes some inconsistencies in the
alert descriptions.
Change-Id: I9abbc0a49f45ba760836c436a3e7e65aa62f652e
This change adds the Telegraf configuration to collect swap metrics, the
associated Prometheus alarms and graphs to the Grafana dashboard.
Change-Id: I3595fd0b8cab06215c620642da69dd29c398396a