Informix Error -32021: The XID already exists.

Cause and resolution

The XID already exists.

This error is same as XAER_DUPID in the X/OPEN XA Specification Standard. For more information, refer to the "Distributed Transaction Processing: The XA Specification".

According to the X/OPEN XA Specification Standard :

In the xa_start context, if neither TMRESUME nor TMJOIN was set in flags (indicating the initial use of *xid) and the XID already exists within the Resource Manager, the Resource Manager must return [XAER_DUPID]. The Resource Manager failed to associate the transaction branch with the thread of control.

Also refer to the Resource Manager guide for more details.

Oninit® Troubleshooting Guidance

Reasons / Common Causes

-32021 is the Informix representation of XAER_DUPID from the X/Open XA Specification — per the official guidance, xa_start was called without TMRESUME or TMJOIN (indicating a new use of the XID), but the XID already exists within the Resource Manager.

xa_start without TMRESUME/TMJOIN set, naming an XID that already exists in the Resource Manager, per the official guidance — the direct, only cause; the Resource Manager fails to associate the branch with the thread of control.

Solutions / Resolution

Use a unique XID for a genuinely new transaction branch, per the official guidance's implication.
If resuming/joining an existing branch was intended, set TMRESUME/TMJOIN, per the official guidance.

Examples

N/A

No specific triggering statement is documented — this is a Resource-Manager-side XA return code.

Diagnostic Checks

Check whether the XID passed to xa_start already exists in the Resource Manager, and whether TMRESUME/TMJOIN should have been set.

Related Errors / Related Topics

-32017 — "The XID is not valid." The mirror-image error (XAER_NOTA), for an unrecognized rather than duplicate XID.

xa_start was called with an XID that already exists in the Resource Manager (XAER_DUPID) — use a unique XID, or set TMRESUME/TMJOIN if resuming/joining was intended.