Fix data loss in logical replication. This commit is a backpatch of commit 4909b38af0 for 13.
Data loss can happen when the DDLs like ALTER PUBLICATION ... ADD TABLE ... or ALTER TYPE ... that don't take a strong lock on table happens concurrently to DMLs on the tables involved in the DDL. This happens because logical decoding doesn't distribute invalidations to concurrent transactions and those transactions use stale cache data to decode the changes. The problem becomes bigger because we keep using the stale cache even after those in-progress transactions are finished and skip the changes required to be sent to the client. This commit fixes the issue by distributing invalidation messages from catalog-modifying transactions to all concurrent in-progress transactions. This allows the necessary rebuild of the catalog cache when decoding new changes after concurrent DDL. The fix for 13 is different from what we did in branches 14 and above, such that for 13, the concurrent DDL changes (from DDL types mentioned earlier) will be visible for any newly started transactions. To make them visible in concurrent transactions, we need to introduce a new change type REORDER_BUFFER_CHANGE_INVALIDATION, already present in branches 14 and greater. We decided not to take the risk of a bigger change and fix the issue partially in 13. Reported-by: hubert depesz lubaczewski <dep...@depesz.com> Reported-by: Tomas Vondra <tomas.von...@enterprisedb.com> Author: Shlok Kyal <shlok.kyal....@gmail.com> Author: Hayato Kuroda <kuroda.hay...@fujitsu.com> Reviewed-by: Zhijie Hou <houzj.f...@fujitsu.com> Reviewed-by: Masahiko Sawada <sawada.m...@gmail.com> Reviewed-by: Amit Kapila <amit.kapil...@gmail.com> Tested-by: Benoit Lobréau <benoit.lobr...@dalibo.com> Discussion: https://postgr.es/m/de52b282-1166-1180-45a2-8d8917ca7...@enterprisedb.com Discussion: https://postgr.es/m/CAD21AoAenVqiMjpN-PvGHL1N9DWnHSq673bfgr6phmBUzx=k...@mail.gmail.com Discussion: https://postgr.es/m/CAD21AoAhU3kp8shYqP=exifdz9szxpfb5wzla0p+vee5j+7...@mail.gmail.com Branch ------ REL_13_STABLE Details ------- https://git.postgresql.org/pg/commitdiff/247ee94150b6fe8906da51afadbedf8acf3c17cf Modified Files -------------- contrib/test_decoding/Makefile | 2 +- .../expected/invalidation_distrubution.out | 20 +++++++ .../specs/invalidation_distrubution.spec | 32 +++++++++++ src/backend/replication/logical/reorderbuffer.c | 64 +++++++++++++++++++--- src/backend/replication/logical/snapbuild.c | 63 +++++++++++++++++---- src/include/replication/reorderbuffer.h | 4 ++ 6 files changed, 164 insertions(+), 21 deletions(-)
