JDBC and HA

Firefly uses JDBC storage for job definitions, nodes, shard leases, executions, outbox, audit logs, and Admin users. H2, PostgreSQL, and MySQL schema scripts are available.

Shard Lease

Scheduler nodes acquire shard ownership through firefly_shard_lease. Lease renewal or takeover increments a fencing token to stop old owners from advancing jobs after network stalls or long pauses.

Key rules:

• All nodes share the same firefly.scheduler.shard-count
• Database time is authoritative for node liveness, leases, and outbox claims
• When the database is unavailable, Firefly does not generate new unfenced executions

Outbox

Runtime cursor CAS, execution creation, and outbox insertion happen in one transaction. Remote dispatch can retry through outbox records.

Schema

The current schema version is 12. Fresh PostgreSQL installations use the canonical minimal script, while existing databases apply ordered dialect migrations.

scripts/postgresql/init.sql
stores/jdbc/src/main/resources/com/firefly/store/jdbc/schema/migrations/{h2,postgresql,mysql}/v12.sql

See Deployment for the script download, checksum, and execution instructions.