Glossary · System coordination, integration and orchestration
Transaction coordinator
Also known as: Transaction manager
German: Transaktionskoordinator
In distributed systems, a transaction coordinator is the component that controls a distributed transaction across several participants, collects their votes and decides whether the transaction is committed or aborted, as in the two-phase commit protocol.
- System integration
In one sentence
A transaction coordinator controls a distributed transaction, collects participants' votes and decides whether to commit or abort.
Example
When a goods receipt must update both the warehouse database and the MES, a transaction coordinator makes sure either both updates are committed or neither is.
How it applies
- Engineering: The coordinator must log its decisions durably, because participants depend on it to resolve in-doubt transactions after failures. A coordinator failure at the wrong moment can block participants.
- Architecture: Many modern service architectures avoid a central transaction coordinator and use the Saga pattern instead, accepting temporary inconsistency. In a saga, an orchestrator can take a similar coordinating role, but with compensation instead of atomic commit.
- Operation: Monitor in-doubt and long-running transactions, and have a documented procedure for resolving them manually.
- Documentation: Document which operations are transactional across systems, the recovery behavior after failures and the procedure for in-doubt transactions for administrators.
Transaction coordinator vs. orchestrator
A transaction coordinator guarantees atomicity: all or nothing. An orchestrator sequences steps of a process and may handle errors with compensation, without atomic guarantees.