Lease Store Role

• ID: storage.role.lease
• Summary: Claims due rows for processor workers and tracks lease ownership.

Interface Methods

SQL Behavior

• PostgreSQL claim query uses FOR UPDATE SKIP LOCKED with due-time and lease-expiry predicates.
• Claim update sets status, lease_owner, lease_expires_at, and increments attempt_count.
• Eligible statuses include pending and failed; expired processing/publishing leases are reclaimable.

Concurrency Model

• Multiple workers can lease in parallel without double-claiming the same row.
• Lost worker case is handled by lease expiry and reclaim.
• Renewal path extends lease_expires_at when the caller still owns the lease.

Index Interaction

• Lease index (status, visible_after, lease_expires_at, created_at) is required for scalable claim scans.
• FIFO-like processing order depends on created_at ordering after due-time filtering.

Observability

• Lease outcomes feed processor counters:
  • litebus.inbox.processor.leases_acquired
  • litebus.outbox.processor.leases_acquired
  • litebus.inbox.processor.lease_lost
  • litebus.outbox.processor.lease_lost
• Queue-depth gauges move rows between pending and processing/publishing states.

Test Coverage

LiteBus.Storage.UnitTests

• Contract tests verify ordering, batch-size limits, deferred visibility handling, and reclaim behavior.
• InMemory lease availability tests validate edge cases around missing lease expiry values.

LiteBus.Storage.IntegrationTests (PostgreSql/)

• PostgreSQL contract suites validate disjoint leasing under concurrency.
• PostgreSqlInboxProcessorLeaseStressTests validates one terminal state under parallel workers.
• End-to-end inbox and outbox processor tests validate lease plus dispatch/publish workflow.

Concrete Example

Two processor instances start at the same time with batch size 10. PostgreSQL lease queries skip rows already locked by the first worker, so each worker gets a separate subset.

Related Docs

• storage.composite.processing-store
• Reliable Messaging