Backends#

Strata ships first-class production backends for both layers.

LayerBackends
MetadataTiKV (raw KV with native ordered scan, lab default), Cassandra (first-class in code, available via --profile cassandra), ScyllaDB (CQL drop-in for Cassandra)
DataRADOS (default, 4 MiB chunks), S3-over-S3 (any S3-compatible upstream), memory (tests only)

Lab compose shape#

The bare docker compose up -d is the TiKV-default 2-replica lab: PD + TiKV for metadata, ceph + ceph-b as the multi-cluster RADOS pair, two strata replicas (strata-a / strata-b) behind an nginx LB on :9999. make up-cassandra (= docker compose --profile cassandra up -d) layers a single Cassandra-backed strata replica (strata-cassandra :9998) on top so both metadata backends can be exercised side-by-side.

The Cassandra meta backend remains first-class in codeinternal/meta/cassandra/** is unchanged, the storetest contract suite still covers it at parity with TiKV, and make test-integration (testcontainers Cassandra) is preserved. The lab default flip is a deployment shape change, not a backend deprecation. See the migration note for the operator-facing checklist.