Circular Buffer to go with Loraserver instance

Need your opinion guys.

We have a running instance of loraserver on a VPS.
Client application is either on a platform or hosted by an other VPS.
What we would like to implement is a database running on the side to get the application messages (both downlink and uplink) stored for a limited time (let’s say up to 180days)
Such database will be used as a circular buffer in case client application is disconnected or a new one is created. In such case it would be able to retrieve previously transmitted data etc…
Now, i’m really disappointed with the choice of the DB. Shall I use a Postgres as it is already running on the machine with Loraserver?

I’d like something that can eventually run into a cluster.

  • Elastic seems oversized to me, and consumes to much ressources for such use I think.
  • open source influxDB does not run in a cluster,
  • Postgres? RethinkDB?
  • any other suggestion?

After all, PostgreSQL is already running on the machine for loraserver, and messages are logged within Postgres so… Maybe Postgres is a wise choice?

Thanks for your help