MDEV-39196: SELECT from information schema fails when FederatedX loses underlying table#4876
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itzanway wants to merge 1 commit intoMariaDB:10.6from
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MDEV-39196: SELECT from information schema fails when FederatedX loses underlying table#4876itzanway wants to merge 1 commit intoMariaDB:10.6from
itzanway wants to merge 1 commit intoMariaDB:10.6from
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…s underlying table When a remote table is unavailable, FederatedX was passing a hard error back to the SQL layer, causing INFORMATION_SCHEMA queries to abort entirely. This patch intercepts the remote error in ha_federatedx::info, downgrades it to a warning using push_warning_printf, and includes the local table name in the warning message so the user knows which table is inaccessible. Signed-off-by: Anway Durge <124391429+itzanway@users.noreply.github.com>
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Description
This PR resolves MDEV-39196 by fixing a bug where
SELECTqueries fromINFORMATION_SCHEMAfail completely when a FederatedX underlying remote table is unreachable.As noted in the issue, the storage engine was previously passing a hard error back to the SQL layer without specifying the guilty local table name, breaking the query and making debugging very difficult.
Implementation Details
ha_federatedx::info()instorage/federatedx/ha_federatedx.ccto catch remote connection and missing table errors, downgrading them from fatal errors to warnings usingpush_warning_printf.share->table_name) into the warning message so users can easily identify exactly which FederatedX table is inaccessible.error_code = 0;after pushing the warning, allowing theINFORMATION_SCHEMAloop to finish scanning the remaining tables in the database instead of aborting.Testing
federatedx_mdev39196.testand.result) to thefederatedsuite to simulate a dropped remote table and verify that the query succeeds while pushing the correct warning.