rmancinasandClaude Opus 5
2169ffa78d
Every field the replication card showed was self-reported by the replica, and the two most reassuring ones lie in the same failure. Seconds_Behind_Source reads 0 when the I/O thread is disconnected — with no incoming event there is nothing to measure staleness against — and Replica_IO_Running only says the network thread is alive, not that it is receiving. Two checks that ask the master instead: - GTID drift, folded into the polled status. GTID_SUBTRACT(master, replica) counts transactions the master executed that the replica has not, so a silent disconnect shows up as a number that climbs instead of a lag that stays 0. It also isolates transactions carried under the replica's OWN server UUID — writes that exist nowhere on the master. There are currently 518 of them, residue of the seed dump load; inert while log_replica_updates is off, and a real divergence the day anyone promotes that box. - A full row-by-row comparison behind a button, over the eight tables my.jorgecuadros.com reads. GTIDs prove the replica applied everything the master sent; they say nothing about rows changed here by another route, which is the one failure the rest of the card cannot see. The comparison hashes CONVERT(col USING binary), not CAST(col AS CHAR). CAST transcodes into the connection character set, and the two servers do not agree on it: the client inside the master's container negotiates latin1, the replica's utf8mb4. Every accented character in a Mexican name, street or note then hashes differently and the tool reports a permanent mismatch on exactly the tables that hold free text. Caught by building it and running it — customers.name gave 3344437324815 against 3339150372121 under CAST, and 3339150372121 on both under CONVERT. All eight tables now match byte for byte. Verify is POST and audited despite reading nothing: it full-scans both servers, so a prefetch or a refresh must not be able to start one. Tests cover the GTID interval arithmetic, which is inclusive at both ends and easy to get wrong by one in the direction that hides a gap. Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>