DROP TABLE on child and UPDATE of parent table can cause an MDL BF-BF
conflict when applied concurrently.
DROP TABLE takes MDL locks on both child and its parent table, however
it only it did not add certification keys for the parent table.
This patch adds the following:
* Append certification keys corresponding to all parent tables
before DROP TABLE replication.
* Fix wsrep_append_fk_parent_table() so that it works when it is
given a table list containing temporary tables.
* Make sure function wsrep_append_fk_parent_table() is only called
for local transaction. That was not the case for ALTER TABLE.
* Add a test case that verifies that UPDATE parent depends on
preceeding DROP TABLE child.
* Adapt galera_ddl_fk_conflict test to work with DROP TABLE as well.
Signed-off-by: Julius Goryavsky <julius.goryavsky@mariadb.com>
A follow-up fix, for original fix for MDEV-21577, which did not handle well
temporary tables.
OPTIMIZE and REPAIR TABLE statements can take a list of tables as argument,
and some of the tables may be temporary. Proper handling of temporary tables
is to skip them and continue working on the real tables. The bad version, skipped all tables,
if a single temporary table was in the argument list. And this resulted so that FK parent
tables were not scnanned for the remaining real tables. Some mtr tests, using OPTIMIZE or REPAIR
for temporary tables caused regressions bacause of this, e.g. galera.galera_optimize_analyze_multi
The fix in this PR opens temporary and real tables first, and in the table handling loop skips
temporary tables, FK parent scanning is done only for real tables.
The test has new scenario for OPTIMIZE and REPAIR issued for two tables of which one is temporary table.
Reviewed-by: Jan Lindström <jan.lindstrom@mariadb.com>
This PR fixes same issue as MDEV-21577 for TRUNCATE TABLE.
MDEV-21577 fixed TOI replication for OPTIMIZE, REPAIR and ALTER TABLE
operating on FK child table. It was later found out that also TRUNCATE
has similar problem and needs a fix.
The actual fix is to do FK parent table lookup before TRUNCATE TOI
isolation and append found FK parent table names in certification key
list for the write set.
PR contains also new test scenario in galera_ddl_fk_conflict test where
FK child has two FK parent tables and there are two DML transactions operating
on both parent tables.
For development convenience, new TO isolation macro was added:
WSREP_TO_ISOLATION_BEGIN_IF and WSREP_TO_ISOLATION_BEGIN_ALTER macro was changed
to skip the goto statement.
Reviewed-by: Jan Lindström <jan.lindstrom@mariadb.com>
Some DDL statements appear to acquire MDL locks for a table referenced by
foreign key constraint from the actual affected table of the DDL statement.
OPTIMIZE, REPAIR and ALTER TABLE belong to this class of DDL statements.
Earlier MariaDB version did not take this in consideration, and appended
only affected table in the certification key list in write set.
Because of missing certification information, it could happen that e.g.
OPTIMIZE table for FK child table could be allowed to apply in parallel
with DML operating on the foreign key parent table, and this could lead to
unhandled MDL lock conflicts between two high priority appliers (BF).
The fix in this patch, changes the TOI replication for OPTIMIZE, REPAIR and
ALTER TABLE statements so that before the execution of respective DDL
statement, there is foreign key parent search round. This FK parent search
contains following steps:
* open and lock the affected table (with permissive shared locks)
* iterate over foreign key contstraints and collect and array of Fk parent
table names
* close all tables open for the THD and release MDL locks
* do the actual TOI replication with the affected table and FK parent
table names as key values
The patch contains also new mtr test for verifying that the above mentioned
DDL statements replicate without problems when operating on FK child table.
The mtr test scenario #1, which can be used to check if some other DDL
(on top of OPTIMIZE, REPAIR and ALTER) could cause similar excessive FK
parent table locking.
Reviewed-by: Aleksey Midenkov <aleksey.midenkov@mariadb.com>
Reviewed-by: Jan Lindström <jan.lindstrom@mariadb.com>
