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
A few tests assumes that the CYCLE timer is always available,
which is not true on some platforms (e.g. ARM).
Fixing the tests not to reply on the CYCLE availability.
Before this fix, the performance schema tables were defined in UPPERCASE.
This was incompatible with the lowercase_table_names option, and caused
issues with the install / upgrade process, when changing the lower case
table names setting *after* the install or upgrade.
With this fix, all performance schema tables are exposed with lowercase names.
As a result, the name of the performance schema table is always lowercase,
no matter how / if / when the lowercase_table_names setting if changed.
The reason for the bug above is unclear but
- Modify pfs_upgrade so that it's result is easier to analyze in case something fails
- Fix several minor weaknesses which could cause that a successing test (either an
already existing or a to be developed one) fails because of imperfect cleanup,
too slow disconnected sessions etc.
should either fix the bug or reduce it's probability or at least
make the analysis of failures easier.
mysql-test/suite/perfschema/include/upgrade_check.inc:
New include file which contains redundant stuff taken from pfs_upgrade.test.
Remove any file which might harm analysis of suspicious results.
mysql-test/suite/perfschema/r/query_cache.result:
Updated results
mysql-test/suite/perfschema/r/selects.result:
Updated results
mysql-test/suite/perfschema/t/bad_option_1.test:
Add the missing remove_file at beginning and end of test.
mysql-test/suite/perfschema/t/bad_option_2.test:
Add the missing remove_file at beginning and end of test.
mysql-test/suite/perfschema/t/global_read_lock.test:
Add a wait routine which ensures that the disconnect is really completed when the test ends.
mysql-test/suite/perfschema/t/pfs_upgrade.test:
- Move redundant actions to include/upgrade_check.inc
- Add preemptive removal of files
mysql-test/suite/perfschema/t/privilege.test:
Add a wait routine which ensures that the disconnect is really completed when the test ends.
mysql-test/suite/perfschema/t/query_cache.test:
Add "flush status" so that counters are reset. (./mtr --repeat=2 perfschema.query_cache failed)
mysql-test/suite/perfschema/t/read_only.test:
Add a wait routine which ensures that the disconnect is really completed when the test ends.
mysql-test/suite/perfschema/t/selects-master.opt:
Needed for running with enabled event-scheduler
mysql-test/suite/perfschema/t/selects.test:
- Correct the sub test for the EVENT scheduler
- Replace "sleep" by wait_routine
- Add premptive cleanups like "DROP ... IF EXISTS ..."
