Remove one of the major sources of race condiitons in mariadb-test.
Normally, mariadb_close() sends COM_QUIT to the server and immediately
disconnects. In mariadb-test it means the test can switch to another
connection and sends queries to the server before the server even
started parsing the COM_QUIT packet and these queries can see the
connection as fully active, as it didn't reach dispatch_command yet.
This is a major source of instability in tests and many - but not all,
still less than a half - tests employ workarounds. The correct one
is a pair count_sessions.inc/wait_until_count_sessions.inc.
Also very popular was wait_until_disconnected.inc, which was completely
useless, because it verifies that the connection is closed, and after
disconnect it always is, it didn't verify whether the server processed
COM_QUIT. Sadly the placebo was as widely used as the real thing.
Let's fix this by making mariadb-test `disconnect` command _to wait_ for
the server to confirm. This makes almost all workarounds redundant.
In some cases count_sessions.inc/wait_until_count_sessions.inc is still
needed, though, as only `disconnect` command is changed:
* after external tools, like `exec $MYSQL`
* after failed `connect` command
* replication, after `STOP SLAVE`
* Federated/CONNECT/SPIDER/etc after `DROP TABLE`
and also in some XA tests, because an XA transaction is dissociated from
the THD very late, after the server has closed the client connection.
Collateral cleanups: fix comments, remove some redundant statements:
* DROP IF EXISTS if nothing is known to exist
* DROP table/view before DROP DATABASE
* REVOKE privileges before DROP USER
etc
- This patch does the following:
git revert --no-commit 673243c893
git revert --no-commit 6c669b9586
git revert --no-commit bacaf2d4f4
git checkout HEAD mysql-test
git revert --no-commit 1fd7d3a9ad
Above command reverts MDEV-29277, MDEV-25581, MDEV-29342.
When binlog is enabled, trasaction takes a lot of time to do
sync operation on innodb fts table. This leads to block
of other transaction commit. To avoid this failure, remove
the fulltext sync operation during transaction commit. So
reverted MDEV-25581 related patches.
We filed MDEV-31105 to avoid the memory consumption
problem during fulltext sync operation.
- innodb_fts.sync_block doesn't make sense after MDEV-25581's patch
because fts cache syncing is done as a part of insert operation
and it leads to completion of select over insert sometimes.
This test case is not relevant any more
Problem:
========
InnoDB FTS requesting the fts sync of the table once the fts
cache size reaches 1/10 of innodb_ft_cache_size. But fts_sync()
releases cache lock when writing the word. By doing this, InnoDB
insert thread increases the innodb fts cache memory and
SYNC operation will take more time to complete.
Solution:
=========
Remove the fts sync operation(FTS_MSG_SYNC_TABLE) from
the fts optimize background thread. Instead of that,
allow user thread to sync the InnoDB fts cache when
the cache size exceeds 512 kb. User thread holds
cache lock while doing cache syncing, it make sure that
other threads doesn't add the docs into the cache.
Removed FTS_MSG_SYNC_TABLE and its related function
because we do remove the FTS_MSG_SYNC_TABLE message
itself.
Removed fts_sync_index_check() and all related
function because other threads doesn't add while
cache operation going on.
