Informix Error -627

Reasons / Common Causes

-627 fires during an Informix STAR distributed transaction's two-phase-commit prepare step, on the coordinator database server itself — per the official guidance, when the coordinator can't prepare, all participants eventually roll back all work associated with the transaction automatically; no administrative intervention is required.

1. A local failure on the coordinator server preventing it from entering the prepared state for its own part of the distributed transaction — per the official guidance's pointer to checking the accompanying ISAM error for the specific reason.
2. Resource contention or a local lock conflict on the coordinator at the moment the prepare step runs, distinct from any problem on the participant servers.
3. A local storage issue on the coordinator (space, corruption) surfacing during the prepare step, the same categories of cause seen elsewhere in the -600s error range.

Solutions / Resolution

1. No administrative intervention is required, per the official guidance — all participants automatically roll back their work once the coordinator can't prepare.
2. Check the accompanying ISAM error, per the official guidance, for the specific reason the coordinator's local transaction couldn't be prepared, if the underlying cause needs investigation (for instance, if this recurs frequently).
3. If this recurs frequently, investigate the coordinator server's local health (space, locks, general load) around the time these failures occur, since the automatic rollback resolves the individual transaction but doesn't address a systemic issue causing repeated failures.

Examples

Checking the accompanying ISAM error after the fact

-- Review application/database server logs for the ISAM error code
-- accompanying -627, to understand why the coordinator's local
-- prepare step failed.

Diagnostic Checks

1. Check the accompanying ISAM error for the specific local reason.
2. If recurring, check the coordinator's local resource health (space, locks, load) around the time of the failures.

Related Errors / Related Topics

• -628 — "Cannot end two-phase commit transaction at coordinator." Same STAR two-phase-commit family, at the end-transaction step rather than prepare.
• -629 — "Cannot end heuristically rolled back transaction." Same family, for a transaction already heuristically rolled back.
• -630 — "Cannot prepare database server server-name for commit." Same family, naming a specific participant server rather than the coordinator itself.

Part of the Informix STAR two-phase-commit error family — automatic rollback handles it; check the accompanying ISAM error only if this recurs and needs investigation.