db1115 crashed with out of memory (MySQL didn't crash):
```
Jun 08 06:14:58 db1115 puppet-agent[9904]: Failed to apply catalog: Cannot allocate memory - /usr/bin/dpkg-query -W --showformat '${Status} ${Package} ${Version}\n' 2>&1
Jun 08 06:15:02 db1115 nrpe[892]: fork() failed with error 12, bailing out...
Jun 08 06:15:03 db1115 systemd[1]: nagios-nrpe-server.service: Main process exited, code=exited, status=2/INVALIDARGUMENT
Jun 08 06:15:03 db1115 systemd[1]: nagios-nrpe-server.service: Failed to fork: Cannot allocate memory
Jun 08 06:15:03 db1115 systemd[1]: nagios-nrpe-server.service: Failed to run 'stop-post' task: Cannot allocate memory
Jun 08 06:15:03 db1115 systemd[1]: nagios-nrpe-server.service: Unit entered failed state.
Jun 08 06:15:03 db1115 systemd[1]: nagios-nrpe-server.service: Failed with result 'exit-code'.
Jun 08 06:15:04 db1115 cron[25646]: /usr/sbin/sendmail: Cannot allocate memory
```
https://grafana.wikimedia.org/render/dashboard-solo/file/server-board.json?refresh=1m&panelId=14&orgId=1&var-server=db1115&var-network=eth0&from=1525847607665&to=1528439607665&width=1000&height=500&tz=UTC%2B02%3A00
https://grafana.wikimedia.org/render/dashboard-solo/file/server-board.json?refresh=1m&panelId=14&orgId=1&var-server=db1115&var-network=eth0&from=1528436037689&to=1528439637689&width=1000&height=500&tz=UTC%2B02%3A00
It started swapping the 22nd at 12:45 apparently: https://grafana.wikimedia.org/render/dashboard-solo/file/server-board.json?refresh=1m&panelId=16&orgId=1&var-server=db1115&var-network=eth0&from=1525847676603&to=1528439676604&width=1000&height=500&tz=UTC%2B02%3A00
MySQL pool size is only 10G