2GB is allocated to the Reaper JVM on startup (see https://github.com/thelastpickle/cassandra-reaper/blob/2.2.4/src/packaging/bin/cassandra-reaper#L90-L91 ).
If you just want to test it out on a machine with only 8GB, you can update the cassandra-reaper script to only use 1GB by setting -Xms1G and -Xmx1G but you won't be able to do much with it. It might also be necessary to reduce the heap allocated to Cassandra down to 2GB so there's enough RAM left for the operating system. For test and production environments, I recommend deploying Reaper on a dedicated machine so it doesn't affect the performance of whatever cluster it is connecting to. Reaper needs a minimum of 2 vCPUs + 2GB of RAM and this works in most cases. As a side note, if you just want to play around with the likes of Reaper and Medusa (backups) then I'd recommend having a look at deploying https://k8ssandra.io/ -- it's a production-ready platform for running Apache Cassandra on Kubernetes with all the tools bundled in: - Reaper <http://cassandra-reaper.io/docs/> for automated repairs - Medusa <https://github.com/thelastpickle/cassandra-medusa/wiki> for backups and restores - Metrics Collector <https://github.com/datastax/metric-collector-for-apache-cassandra> for monitoring with Prometheus + Grafana - *Stargate.io <https://stargate.io/>* for accessing your data using REST, GraphQL and JSON Doc APIs - Traefik templates for k8s cluster ingress Cheers! >
