InfluxDB stores the Time Series Data.
Good luck getting InfluxDB or Grafana to produce the graphs you want (like gaps in a sequential series).
For maximum flexibility, be prepared to use the InfluxDB API to get the data back out. Here is an example of this gem:
curl -G --user 'user' 'https://dashboard.example.com/influxdb:8086/query?pretty=true' --data-urlencode "db=iotdashdb" --data-urlencode "q=SELECT \"rssi\" FROM \"HomeSensors\" WHERE \"device\"=~/3996/"