diff --git a/src/backend/distributed/transaction/transaction_recovery.c b/src/backend/distributed/transaction/transaction_recovery.c index f25823b30..c114a2ed3 100644 --- a/src/backend/distributed/transaction/transaction_recovery.c +++ b/src/backend/distributed/transaction/transaction_recovery.c @@ -347,7 +347,23 @@ RecoverWorkerTransactions(WorkerNode *workerNode) } systable_endscan(scanDescriptor); - table_close(pgDistTransaction, NoLock); + + /* + * Here we release the lock on pg_dist_transaction while closing it to avoid + * deadlocks that might occur because of trying to acquire a lock on + * pg_dist_authinfo while holding a lock on pg_dist_transaction. Such a scenario + * can only cause a deadlock if another transaction is trying to acquire a strong + * lock on pg_dist_transaction while holding a lock on pg_dist_authinfo. As of + * today, we (implicitly) acquire a strong lock on pg_dist_transaction only when + * upgrading Citus to 11.3-1 and this happens when creating a REPLICA IDENTITY on + * pg_dist_transaction. + * + * And reglardless of the code-path we are in, it should be okay to release the + * lock now because all we do after this point is to abort the prepared + * transactions that are not part of an in-progress distributed transaction and + * releasing the lock before doing so should be just fine. + */ + table_close(pgDistTransaction, RowExclusiveLock); if (!recoveryFailed) { diff --git a/src/test/regress/expected/isolation_create_restore_point.out b/src/test/regress/expected/isolation_create_restore_point.out index 3b1bdf9eb..dce15a35d 100644 --- a/src/test/regress/expected/isolation_create_restore_point.out +++ b/src/test/regress/expected/isolation_create_restore_point.out @@ -147,16 +147,15 @@ recover_prepared_transactions step s2-create-restore: SELECT 1 FROM citus_create_restore_point('citus-test'); - -step s1-commit: - COMMIT; -step s2-create-restore: <... completed> ?column? --------------------------------------------------------------------- 1 (1 row) +step s1-commit: + COMMIT; + starting permutation: s1-begin s1-drop s2-create-restore s1-commit create_reference_table diff --git a/src/test/regress/spec/isolation_create_restore_point.spec b/src/test/regress/spec/isolation_create_restore_point.spec index 2cdc66f85..c62a64a44 100644 --- a/src/test/regress/spec/isolation_create_restore_point.spec +++ b/src/test/regress/spec/isolation_create_restore_point.spec @@ -154,7 +154,10 @@ permutation "s1-begin" "s1-ddl" "s2-create-restore" "s1-commit" // verify that citus_create_restore_point is not blocked by concurrent COPY (only commit) permutation "s1-begin" "s1-copy" "s2-create-restore" "s1-commit" -// verify that citus_create_restore_point is blocked by concurrent recover_prepared_transactions +// verify that citus_create_restore_point is partially blocked by concurrent recover_prepared_transactions. +// In the test output, we won't be able to explicitly observe this since +// recover_prepared_transactions unblocks citus_create_restore_point after in-progress prepared transactions +// are recovered. permutation "s1-begin" "s1-recover" "s2-create-restore" "s1-commit" // verify that citus_create_restore_point is blocked by concurrent DROP TABLE