The ScadaBridge central shared-store live gate proved SqlServerSecretsStoreMigrator's
"safe to run concurrently" claim false on a virgin database: Serializable isolation does
not serialize the IF NOT EXISTS metadata probes against another session's in-flight
CREATE, so of two central nodes booting together the loser died with SqlException 2714
("There is already an object named 'zbsecrets'") — the retry filter covered only
deadlock 1205. Losing such a race means the object now exists (the desired end state),
so 2714 (schema/table), 1913 (index) and 2627 (schema_version MERGE-insert PK) are now
retryable alongside 1205; the retry re-runs the idempotent IF NOT EXISTS path.
Classification scans the whole SqlException.Errors collection (2714 arrives stacked with
2759), the retry cap keeps genuine conflicts failing closed, and 2705 is deliberately
excluded (unreachable — columns live in a single CREATE TABLE statement). Predicate
extracted as an internal static pinned by offline tests; live suite gains an env-gated
4-concurrent-migrators virgin-database test. Six packages pushed to the Gitea feed at
0.5.1.
Claude-Session: https://claude.ai/code/session_014WNM4vjoVksyyBraTXSZE1
Joseph Doherty
31ca9407a6