MDEV-30014 Spider should not second guess server when locking / unlocking
This fixes MDEV-30014, MDEV-29456, MDEV-29667, and MDEV-30049.
The server may ask storage engines to unlock when the original sql
command is not UNLOCK. This patch makes sure that spider honours these
requests, so that the server has the correct idea which tables are
locked and which are not.
MDEV-29456, MDEV-29667, MDEV-30049: a later LOCK statement would, as
the first step, unlock locked tables and clear the OPTION_TABLE_LOCK
bit in thd->variables.option_bits, as well as locked_tables_list,
indicating no tables are locked. If Spider does not unlock because the
sql command is not UNLOCK, and if after this the LOCK statement fails
to lock any tables, these indications that no tables are locked
remains, so a later UNLOCK TABLES; statement would not try to unlock
any table. Causing later statements requiring mdl locks to hang on
waiting until lock_wait_timeout (default 1h) has passed.
MDEV-30014: when a LOCK statement tries to lock more than one tables,
say t2 and t3 as in mdev_30014.test, and t2 succeeds but t3 fails, the
sql layer would try to undo by unlocking t2, and again, if Spider does
not honour this request, the sql layer would assume t2 has been
unlocked, but later actions on t2 or t2's remote table could hang on
waiting for the mdl.
MDEV-32515 Use $MYSQLD_LAST_CMD in spider/bugfix.mdev_30370
$MYSQLD_CMD uses .1 as the defaults-group-suffix, which could cause
the use of the default port (3306) or socket, which will fail in
environment where these defaults are already in use by another server.
Adding an extra --defaults-group-suffix=.1.1 does not help, because
the first flag wins.
So we use $MYSQLD_LAST_CMD instead, which uses the correct suffix.
The extra innodb buffer pool warning is irrelevant to the goal of the
test (running --wsrep-recover with --plug-load-add=ha_spider should
not cause hang)
MDEV-32507 Spider: Use $MTR_SUITE_DIR for init-file files
This should fix certain CI builds where the spider suite test files
and the main suite test files do not follow the same relative paths
relations as the mariadb source.
MDEV-29963 MDEV-31357 Spider should clear its lock lists when locking fails
Spider populates its lock lists (a hash) in store_lock(), and normally
clears them in the actual lock_tables(). However, if lock_tables()
fails, there's no reset_lock() method for storage engine handlers,
which can cause bad things to happen. For example, if one of the table
involved is dropped and recreated, or simply TRUNCATEd, when executing
LOCK TABLES again, the lock lists would be queried again in
store_lock(), which could cause access to freed space associated with
the dropped table.
MDEV-26247 Re-implement spider gbh query rewrite of tables
Spider GBH's query rewrite of table joins is overly complex and
error-prone. We replace it with something closer to what
dbug_print() (more specifically, print_join()) does, but catered to
spider.
More specifically, we replace the body of
spider_db_mbase_util::append_from_and_tables() with a call to
spider_db_mbase_util::append_join(), and remove downstream append_X
functions.
We make it handle const tables by rewriting them as (select 1). This
fixes the main issue in MDEV-26247.
We also ban semijoin from spider gbh, which fixes MDEV-31645 and
MDEV-30392, as semi-join is an "internal" join, and "semi join" does
not parse, and it is different from "join" in that it deduplicates the
right hand side
Not all queries passed to a group by handler are valid (MDEV-32273),
for example, a join on expr may refer outer fields not in the current
context. We detect this during the handler creation when walking the
join. See also gbh_outer_fields_in_join.test.
It also skips eliminated tables, which fixes MDEV-26193.
Spider gbh query rewrite should get table for fields in a simple way.
Add a method spider_fields::find_table that searches its table holders
to find table for a given field. This way we will be able to get rid
of the first pass during the gbh creation where field_chains and
field_holders are created.
We also check that the field belongs to a spider table while walking
through the query, so we could remove
all_query_fields_are_query_table_members(). However, this requires an
earlier creation of the table_holder so that tables are added before
checking. We do that, and in doing so, also decouple table_holder and
spider_fields
