Cassandra Exporter

The Cassandra Exporter connects to Cassandra's JMX port and exports metrics
as Prometheus metrics. It must run on every Cassandra node.

Key features:
- Exports Cassandra JMX metrics as Prometheus metrics
- Configurable JMX connection and metric blacklisting
- Supports Cassandra 2.2.x, 3.x, and 4.x

Default ports:
- Metrics endpoint: 8080
- Cassandra JMX (target): 7199

Configuration:
- snap set cassandra-exporter cassandra.host=localhost:7199
- snap set cassandra-exporter web.listen-port=8080
- snap set cassandra-exporter cassandra.user=jmxuser
- snap set cassandra-exporter cassandra.password=jmxpassword

The exporter config file is stored at: $SNAP_COMMON/config.yml