Commit graph

2129 commits

Author SHA1 Message Date
Georgi Kodinov
08b7c7aeb4 merge 2010-07-16 18:04:39 +03:00
Georgi Kodinov
dcaef2424e Addendum to bug #53814 : test results updates 2010-07-16 16:56:33 +03:00
Davi Arnaut
7e6eb10c49 Bug#53613: mysql_upgrade incorrectly revokes ...
Post-merge fix: adjust line numbers in pfs_upgrade test case
result given that mysql_system_tables_fix.sql was modified.
2010-07-15 18:57:47 -03:00
Davi Arnaut
711c318c07 Merge of mysql-trunk-bugfixing into mysql-trunk-merge. 2010-07-15 10:47:50 -03:00
Davi Arnaut
07e7b4d6fe WL#5486: Remove code for unsupported platforms
Remove Netware specific code.
2010-07-15 08:13:30 -03:00
Georgi Kodinov
6fb7b89fc7 merge 2010-07-09 15:40:38 +03:00
Georgi Kodinov
51ada4dcb0 Addendum #2 to bug #53095 : fixed a bad testcase result. 2010-07-09 15:17:47 +03:00
Guilhem Bichot
18bde950e3 backport of guilhem@mysql.com-20100628140739-i9vy8ugxp1v5aspb
from next-mr-bugfixing:
BUG#54682 "set sql_select_limit=0 does not work"; let SQL_SELECT_LIMIT=0
work like it does in 5.1.


mysql-test/suite/sys_vars/r/sql_select_limit_func.result:
  before the fix, the SET would emit a warning (0 being rounded up to 1)
  and SELECTs would return one row.
sql/sys_vars.cc:
  0 is allowed, it means an implicit LIMIT 0 (i.e. no rows returned)
2010-07-08 14:36:10 +02:00
Luis Soares
b84b607e87 BUG 54842: automerged bzr bundle in mysql-trunk-bugfixing. 2010-07-07 23:27:52 +01:00
Alexander Nozdrin
e1bbe2443c Fix sys_vars.large_files_support_basic failure. 2010-07-06 17:06:07 +04:00
Sergey Vojtovich
4a739a14c0 BUG#54832 - Comment for MyISAM says it is a default engine
Adjusted tests.

mysql-test/r/information_schema.result:
  Adjusted tests.
mysql-test/suite/funcs_1/r/is_engines_myisam.result:
  Adjusted tests.
2010-07-05 11:34:29 +04:00
unknown
43ef6da6ef Manul merge 2010-07-04 12:36:09 +08:00
unknown
1a17d7e807 The following statements support the CURRENT_USER() where a user is needed.
DROP USER 
RENAME USER CURRENT_USER() ...
GRANT ... TO CURRENT_USER()
REVOKE ... FROM CURRENT_USER()
ALTER DEFINER = CURRENT_USER() EVENTbut, When these statements are binlogged, CURRENT_USER() just is binlogged
as 'CURRENT_USER()', it is not expanded to the real user name. When slave 
executes the log event, 'CURRENT_USER()' is expand to the user of slave 
SQL thread, but SQL thread's user name always NULL. This breaks the replication.

After this patch, session's user will be written into query log events 
if these statements call CURREN_USER() or 'ALTER EVENT' does not assign a definer.


mysql-test/include/diff_tables.inc:
  Expend its abilities.
  Now it can diff not only in sessions of 'master' and 'slave', but 
  other sessions as well.
sql/log_event.cc:
  session's user will be written into Query_log_event, if is_current_user_used() is TRUE.
  On slave SQL thread, Only thd->invoker is written into Query_log_event,
  if it exists.
sql/sql_acl.cc:
  On slave SQL thread, grantor should copy from thd->invoker, if it exists
sql/sql_class.h:
  On slave SQL thread, thd->invoker is used to store the applying event's
  invoker.
2010-07-04 12:02:49 +08:00
Davi Arnaut
54a5c00de9 Unset the execute bit where it's not needed. 2010-07-03 20:17:03 -03:00
Alexander Nozdrin
aee88bc8aa Disabling failing NDB-tests due to Bug 54850 and Bug 54851. 2010-07-02 10:23:00 +04:00
Alfranio Correia
68ecc965a6 WL#5344 2010-06-30 20:37:41 +01:00
Alfranio Correia
c9221a2a6f BUG#53259 Unsafe statement binlogged in statement format w/MyIsam temp tables
BUG#54872 MBR: replication failure caused by using tmp table inside transaction 
      
Changed criteria to classify a statement as unsafe in order to reduce the
number of spurious warnings. So a statement is classified as unsafe when
there is on-going transaction at any point of the execution if:

1. The mixed statement is about to update a transactional table and
a non-transactional table.

2. The mixed statement is about to update a temporary transactional
table and a non-transactional table.
      
3. The mixed statement is about to update a transactional table and
read from a non-transactional table.

4. The mixed statement is about to update a temporary transactional
table and read from a non-transactional table.

5. The mixed statement is about to update a non-transactional table
and read from a transactional table when the isolation level is
lower than repeatable read.

After updating a transactional table if:

6. The mixed statement is about to update a non-transactional table
and read from a temporary transactional table.
 
7. The mixed statement is about to update a non-transactional table
 and read from a temporary transactional table.

8. The mixed statement is about to update a non-transactionala table
   and read from a temporary non-transactional table.
     
9. The mixed statement is about to update a temporary non-transactional
table and update a non-transactional table.
     
10. The mixed statement is about to update a temporary non-transactional
table and read from a non-transactional table.
     
11. A statement is about to update a non-transactional table and the
option variables.binlog_direct_non_trans_update is OFF.

The reason for this is that locks acquired may not protected a concurrent
transaction of interfering in the current execution and by consequence in
the result. So the patch reduced the number of spurious unsafe warnings.

Besides we fixed a regression caused by BUG#51894, which makes temporary
tables to go into the trx-cache if there is an on-going transaction. In
MIXED mode, the patch for BUG#51894 ignores that the trx-cache may have
updates to temporary non-transactional tables that must be written to the
binary log while rolling back the transaction.
      
So we fix this problem by writing the content of the trx-cache to the
binary log while rolling back a transaction if a non-transactional
temporary table was updated and the binary logging format is MIXED.
2010-06-30 16:25:13 +01:00
Sergey Glukhov
0ecd5b2975 5.1-bugteam->trunk-merge merge 2010-06-30 17:16:56 +04:00
Luis Soares
e0ece40b64 BUG#54842: DROP TEMPORARY TABLE not binlogged after manual
switching binlog format to ROW

BUG 52616 fixed the case which the user would switch from STMT to
ROW binlog format, but the server would silently ignore it. After
that fix thd->is_current_stmt_binlog_format_row() reports correct
value at logging time and events are logged in ROW (as expected)
instead of STMT as they were previously and wrongly logged.

However, the fix was only partially complete, because on
disconnect, at THD cleanup, the implicit logging of temporary
tables is conditionally performed. If the binlog_format==ROW and
thd->is_current_stmt_binlog_format_row() is true then DROPs are
not logged. Given that the user can switch from STMT to ROW, this
is wrong because the server cannot tell, just by relying on the
ROW binlog format, that the tables have been dropped before. This
is effectively similar to the MIXED scenario when a switch from
STMT to ROW is triggered.

We fix this by removing this condition from
close_temporary_tables.

mysql-test/extra/binlog_tests/drop_temp_table.test:
  Added binlog test case.
mysql-test/suite/binlog/r/binlog_row_drop_tmp_tbl.result:
  Result changes because:
  - there is a missing drop on three temporary tables
  - it now contains results for the test added
mysql-test/suite/binlog/r/binlog_row_mix_innodb_myisam.result:
  Result now contains the implicit drop for the temporary table.
mysql-test/suite/binlog/r/binlog_stm_drop_tmp_tbl.result:
  Result file changed because it now contains results for added
  test case.
mysql-test/suite/rpl/r/rpl_drop_temp.result:
  Result file changed because it now contains results for added
  test case.
mysql-test/suite/rpl/t/rpl_drop_temp.test:
  Added replication test case.
sql/sql_base.cc:
  Removed the condition that would make the server to skip
  logging implicit drops when ROW binary log format mode was 
  in use.
  Additionally, deployed DBUG_ENTER/RETURN macros.
2010-06-29 11:54:58 +01:00
Davi Arnaut
3a57c8d1d9 Merge of mysql-5.1-bugteam into mysql-trunk-merge. 2010-06-28 19:18:22 -03:00
Davi Arnaut
bfd3b7a109 Revert Bug#48321 due to build breakage and failing tests. 2010-06-28 17:59:41 -03:00
Alfranio Correia
77854696c4 merge mysql-5.1-bugteam (local) --> mysql-5.1-bugteam 2010-06-27 18:31:42 +01:00
unknown
af01afa0f6 Manual merge 2010-06-27 13:51:45 +08:00
unknown
451cea3f62 The following statements support the CURRENT_USER() where a user is needed.
DROP USER 
RENAME USER CURRENT_USER() ...
GRANT ... TO CURRENT_USER()
REVOKE ... FROM CURRENT_USER()
ALTER DEFINER = CURRENT_USER() EVENTbut, When these statements are binlogged, CURRENT_USER() just is binlogged
as 'CURRENT_USER()', it is not expanded to the real user name. When slave 
executes the log event, 'CURRENT_USER()' is expand to the user of slave 
SQL thread, but SQL thread's user name always NULL. This breaks the replication.

After this patch, session's user will be written into query log events 
if these statements call CURREN_USER() or 'ALTER EVENT' does not assign a definer.


mysql-test/include/diff_tables.inc:
  Expend its abilities.
  Now it can diff not only in sessions of 'master' and 'slave', but 
  other sessions as well.
mysql-test/include/rpl_diff_tables.inc:
  Diff the same table between master and slaves.
sql/log_event.cc:
  session's user will be written into Query_log_event, if is_current_user_used() is TRUE.
  On slave SQL thread, Only thd->variables.current_user is written into Query_log_event,
  if it exists.
sql/sql_acl.cc:
  On slave SQL thread, grantor should copy from thd->variables.current_user, if it exists
sql/sql_class.h:
  On slave SQL thread, thd->variables.current_user is used to store the applying event's
  invoker.
2010-06-27 12:42:06 +08:00
Jon Olav Hauglid
47edc4cade Bug #50124 Rpl failure on DROP table with concurrent txn/non-txn
DML flow and SAVEPOINT

The problem was that replication could break if a transaction involving
both transactional and non-transactional tables was rolled back to a
savepoint. It broke if a concurrent connection tried to drop a
transactional table which was locked after the savepoint was set.
This DROP TABLE completed when ROLLBACK TO SAVEPOINT was executed as the
lock on the table was dropped by the transaction. When the slave later
tried to apply the binlog, it would fail as the table would already
have been dropped.

The reason for the problem is that transactions involving both
transactional and non-transactional tables are written fully to the
binlog during ROLLBACK TO SAVEPOINT. At the same time, metadata locks
acquired after a savepoint, were released during ROLLBACK TO SAVEPOINT.
This allowed a second connection to drop a table only used between
SAVEPOINT and ROLLBACK TO SAVEPOINT. Which caused the transaction binlog
to refer to a non-existing table when it was written during ROLLBACK
TO SAVEPOINT.

This patch fixes the problem by not releasing metadata locks when
ROLLBACK TO SAVEPOINT is executed if binlogging is enabled.
2010-06-25 09:32:24 +02:00
Vasil Dimov
ea73b23e4a Merge mysql-trunk -> mysql-trunk-merge 2010-06-22 18:58:28 +03:00
Magne Mahre
7657ee10f8 Post-push fixups for WL#5349
mysql-test/suite/perfschema/t/no_threads-master.opt:
  Innodb will start multiple threads, which is
  not compatible with --one-thread.   Disable
  innodb to be able to run the test case.
2010-06-22 12:13:47 +02:00
Sergey Glukhov
1704783e84 5.1-bugteam->trunk-merge merge 2010-06-21 15:19:14 +04:00
Joerg Bruehe
100f88b86e Automerge part of mysql-trunk-bugfixing into mysql-trunk-merge. 2010-06-21 12:52:03 +02:00
Magne Mahre
240afacf8f Post-push fixup for WL#5349
InnoDB came in a new version "simultanously" with the
commit.  This patch is a minor change to the new innodb
regression test suite.
2010-06-20 22:43:34 +02:00
Ramil Kalimullin
5088fb1394 Fix for bug #54393: crash and/or valgrind errors in
mysql_client_binlog_statement

Problem: server may read from unassigned memory performing
"wrong" BINLOG queries.

Fix: never read from unassigned memory.


mysql-test/suite/binlog/r/binlog_base64_flag.result:
  Fix for bug #54393: crash and/or valgrind errors in
  mysql_client_binlog_statement
    - test result.
mysql-test/suite/binlog/t/binlog_base64_flag.test:
  Fix for bug #54393: crash and/or valgrind errors in
  mysql_client_binlog_statement
    - test case.
sql/sql_binlog.cc:
  Fix for bug #54393: crash and/or valgrind errors in
  mysql_client_binlog_statement
    - coded_len should not count trailing '/0';
    - never read from unassigned memory.
2010-06-18 21:32:23 +04:00
Magne Mahre
32b7e60e42 WL#5349 Change default storage engine to InnoDB
The default storage engine is changed from MyISAM to
InnoDB, in all builds except for the embedded server.

In addition, the following system variables are 
changed:

  * innodb_file_per_table is enabled
  * innodb_strict_mode is enabled
  * innodb_file_format_name_update is changed
    to 'Barracuda'

The test suite is changed so that tests that do not
explicitly include the have_innodb.inc are run with
--default-storage-engine=MyISAM.  This is to ease the
transition, so that most regression tests are run
with the same engine as before.

Some tests are disabled for the embedded server
regression test, as the output of certain statements
will be different that for the regular server
(i.e SELECT @@default_storage_engine).  This is to
ease transition.



mysql-test/mysql-test-run.pl:
  The regression test suite now adds a
  --default-storage-engine=MyISAM for all non-innodb 
  tests.  This behaviour can be controlled by the
  default-myisam switch in mysql-test-run
mysql-test/t/bootstrap-master.opt:
  The bootstrap test can only be run without InnoDB
  as it starts several mysqld instances on the same
  datadir. This is possible with MyISAM, but not
  with InnoDB.
storage/innobase/CMakeLists.txt:
  Build InnoDB per default
storage/innobase/handler/ha_innodb.cc:
  Change default values for system variables
  
    Enable file_per_table
    Enable strict_mode
    Upgrade default file format to Barracuda
2010-06-17 22:51:35 +02:00
Konstantin Osipov
cc6dabba37 Merge trunk-bugfixing -> trunk-runtime 2010-06-17 17:31:51 +04:00
Vasil Dimov
e4b19dd475 Adjust innodb_mysql.result after the resolved conflict from the merge 2010-06-17 12:59:53 +03:00
Vasil Dimov
b31987c141 Merge mysql-trunk-bugfixing -> mysql-trunk-innodb 2010-06-17 12:41:20 +03:00
Jimmy Yang
0cbc668fc2 This change splits innodb_file_format_check into innodb_file_format_check
and innodb_file_format_max two system variables. And this also fixes
bug #53654 after 2nd shutdown innodb_file_format_check attains strange
values.

rb://366 approved by Marko
2010-06-17 02:13:53 -07:00
Alexander Nozdrin
af632d82d9 Auto-merge from mysql-trunk. 2010-06-17 10:13:11 +04:00
Alfranio Correia
cdc4e9ebce merge mysql-5.1-bugteam (local) --> mysql-5.1-bugteam 2010-06-17 01:25:07 +01:00
Konstantin Osipov
91a7b14705 Merge trunk-bugfixing -> trunk-runtime 2010-06-16 12:50:36 +04:00
Tor Didriksen
f88e6af0bb Bug #53261 MTR tests archive_plugin and blackhole_plugin fail when compiling with cmake
Let mtr lookup the plugins, rather than hard-coding autotools lib path.


mysql-test/include/not_parallel.inc:
  Add new feature for skipping when running in parallel.
mysql-test/mysql-test-run.pl:
  Use find_plugin to locate plugins.
  Export opt_parallel in environment.
mysql-test/suite/federated/federated_plugin-master.opt:
  Use plugin dir from mtr.
mysql-test/suite/federated/federated_plugin.test:
  Skip test, disabled.
mysql-test/t/archive_plugin-master.opt:
  Use plugin dir from mtr.
mysql-test/t/archive_plugin.test:
  Skip test if running in parallel.
mysql-test/t/blackhole_plugin-master.opt:
  Use plugin dir from mtr.
mysql-test/t/blackhole_plugin.test:
  Skip test if running in parallel.
2010-06-14 11:23:49 +02:00
Marko Mäkelä
ac3c92e435 Merge a change from mysql-5.1-innodb:
------------------------------------------------------------
revno: 3507
revision-id: marko.makela@oracle.com-20100610125623-ar6qf4w2pv2kr7mb
parent: sergey.glukhov@sun.com-20100609121718-04mpk5kjxvnrxdu8
committer: Marko Mäkelä <marko.makela@oracle.com>
branch nick: 5.1-innodb
timestamp: Thu 2010-06-10 15:56:23 +0300
message:
  Bug #38999: Re-enable innodb_multi_update.test
2010-06-14 09:50:30 +03:00
Marko Mäkelä
28ec745704 Merge a change from mysql-5.1-innodb:
------------------------------------------------------------
revno: 3506
revision-id: sergey.glukhov@sun.com-20100609121718-04mpk5kjxvnrxdu8
parent: sergey.glukhov@sun.com-20100609120734-ndy2281wau9067zv
committer: Sergey Glukhov <Sergey.Glukhov@sun.com>
branch nick: mysql-5.1-innodb
timestamp: Wed 2010-06-09 16:17:18 +0400
message:
  Bug#38999 valgrind warnings for update statement in function compare_record()
  (InnoDB plugin branch)

 @ mysql-test/suite/innodb_plugin/r/innodb_mysql.result
    test case

 @ mysql-test/suite/innodb_plugin/t/innodb_mysql.test
    test case

 @ storage/innodb_plugin/row/row0sel.c
    init null bytes with default values as they might be
    left uninitialized in some cases and these uninited bytes
    might be copied into mysql record buffer that leads to
    valgrind warnings on next use of the buffer.
2010-06-14 09:35:01 +03:00
Magne Mahre
75d7bb91a3 Post-commit fixes after the push for Bug#20837 et. al.
mysql-test/suite/innodb/r/innodb_information_schema.result:
  The transaction is in REPEATABLE READ, since the
  iso level was changed to SERIALIZABLE only for the 
  previous trx.
mysql-test/suite/innodb/t/innodb-semi-consistent.test:
  'commit' was missing from the original patch
mysql-test/t/parser.test:
  Moved the test for Bug#46527 to parser_not_embedded,
  since "disconnect default" isn't allowed with
  the embedded server.
mysql-test/t/parser_not_embedded.test:
  Moved the test for Bug#46527 to parser_not_embedded,
  since "disconnect default" isn't allowed with
  the embedded server.
2010-06-09 10:46:24 +02:00
Magne Mahre
db716d11af Bug#20837 Apparent change of isolation level during transaction
Bug#46527 COMMIT AND CHAIN RELEASE does not make sense
Bug#53343 completion_type=1, COMMIT/ROLLBACK AND CHAIN don't 
          preserve the isolation level
Bug#53346 completion_type has strange effect in a stored 
          procedure/prepared statement

Added test cases to verify the expected behaviour of :
 SET SESSION TRANSACTION ISOLATION LEVEL, 
 SET TRANSACTION ISOLATION LEVEL,
 @@completion_type,
 COMMIT AND CHAIN,
 ROLLBACK AND CHAIN
 ..and some combinations of the above
2010-06-08 19:47:10 +02:00
Kristofer Pettersson
f6b5b29730 Automerge 2010-06-08 12:19:20 +02:00
Kristofer Pettersson
fd674a938c merge 5.1-bugteam => trunk-merge 2010-06-08 12:17:07 +02:00
Kristofer Pettersson
cf2e7c770c Bug#53191 Lock_time in slow log is negative when logging stored routines
Logging slow stored procedures caused the slow log to write 
very large lock times. The lock times was a result of a 
negative number being cast to an unsigned integer.
The reason the lock time appeard negative was because 
one of the measurements points was reset after execution
causing it to change order with the start time of the 
statement.
      
This bug is related to bug 47905 which in turn was 
introduced because of a joint fix for 12480,12481,12482 and 11587.

The fix is to only reset the start_time before any statement
execution in a SP while not resetting start_utime or
utime_after_lock which are used for measuring the 
performance of the SP. Start_time is used to set the
timestamp on the replication event which controlls how
the slave interprets time functions like NOW().
2010-06-08 10:58:19 +02:00
unknown
a961688d2e Postfix for bug49741 2010-06-08 10:27:34 +08:00
Alexander Nozdrin
f29d24b0f8 Manual merge from mysql-trunk-bugfixing.
Conflicts:
  - BUILD/SETUP.sh
  - mysql-test/mysql-test-run.pl
  - mysql-test/r/partition_error.result
  - mysql-test/t/disabled.def
  - mysql-test/t/partition_error.test
  - sql/share/errmsg-utf8.txt
2010-06-07 12:47:04 +04:00
Dmitry Lenev
9dbd9ce185 Patch that changes approach to how we acquire metadata
locks for DML statements and changes the way MDL locks
are acquired/granted in contended case.

Instead of backing-off when a lock conflict is encountered
and waiting for it to go away before restarting open_tables()
process we now wait for lock to be released without releasing
any previously acquired locks. If conflicting lock goes away
we resume opening tables. If waiting leads to a deadlock we
try to resolve it by backing-off and restarting open_tables()
immediately.

As result both waiting for possibility to acquire and
acquiring of a metadata lock now always happen within the
same MDL API call. This has allowed to make release of a lock
and granting it to the most appropriate pending request an
atomic operation.
Thanks to this it became possible to wake up during release
of lock only those waiters which requests can be satisfied
at the moment as well as wake up only one waiter in case
when granting its request would prevent all other requests
from being satisfied. This solves thundering herd problem
which occured in cases when we were releasing some lock and
woke up many waiters for SNRW or X locks (this was the issue
in bug#52289 "performance regression for MyISAM in sysbench
OLTP_RW test".
This also allowed to implement more fair (FIFO) scheduling
among waiters with the same priority.
It also opens the door for introducing new types of requests
for metadata locks such as low-prio SNRW lock which is
necessary in order to support LOCK TABLES LOW_PRIORITY WRITE.

Notice that after this sometimes can report ER_LOCK_DEADLOCK
error in cases in which it has not happened before.
Particularly we will always report this error if waiting for
conflicting lock has happened in the middle of transaction
and resulted in a deadlock. Before this patch the error was
not reported if deadlock could have been resolved by backing
off all metadata locks acquired by the current statement.

mysql-test/r/mdl_sync.result:
  Added test coverage for some aspects of deadlock handling in
  metadata locking subsystem.
  Adjusted test case after removing back-off in general case
  when conflicting metadata lock is encountered during
  open_tables() (now this happens only if waiting for
  conflicting lock to go away leads to a deadlock).
mysql-test/r/sp_sync.result:
  Adjusted test case after removing back-off in general case
  when conflicting metadata lock is encountered during
  open_tables() (now this happens only if waiting for
  conflicting lock to go away leads to a deadlock).
mysql-test/suite/perfschema/r/dml_setup_instruments.result:
  Adjusted test results after renaming MDL_context::
  m_waiting_for_lock rwlock to m_LOCK_waiting_for.
mysql-test/suite/rpl/r/rpl_sp.result:
  Adjusted test case after implementing new approach to
  acquiring metadata locks in open_tables(). We no longer
  release all MDL locks acquired by statement before waiting
  for conflicting lock to go away. As result DROP FUNCTION
  statement has to wait for DML statement which managed to
  acquire metadata lock on function being dropped and now
  waits for other conflicting metadata lock to go away.
mysql-test/suite/rpl/t/rpl_sp.test:
  Adjusted test case after implementing new approach to
  acquiring metadata locks in open_tables(). We no longer
  release all MDL locks acquired by statement before waiting
  for conflicting lock to go away. As result DROP FUNCTION
  statement has to wait for DML statement which managed to
  acquire metadata lock on function being dropped and now
  waits for other conflicting metadata lock to go away.
mysql-test/t/mdl_sync.test:
  Added test coverage for some aspects of deadlock handling in
  metadata locking subsystem.
  Adjusted test case after removing back-off in general case
  when conflicting metadata lock is encountered during
  open_tables() (now this happens only if waiting for
  conflicting lock to go away leads to a deadlock).
mysql-test/t/sp_sync.test:
  Adjusted test case after removing back-off in general case
  when conflicting metadata lock is encountered during
  open_tables() (now this happens only if waiting for
  conflicting lock to go away leads to a deadlock).
sql/mdl.cc:
  Changed MDL subsystem to support new approach to acquring
  metadata locks in open tables and more fair and efficient
  scheduling of metadata locks. To implement this:
  - Made releasing of the lock and granting it to the most
    appropriate pending request atomic operation. As result it
    became possible to wake up only those waiters requests from
    which can be satisfied at the moment as well as wake-up
    only one waiter in case when granting its request would
    prevent all other requests from being satisfied.
    This solved thundering herd problem which occured in cases
    when we were releasing some lock and woke up many waiters
    for SNRW or X locks (this was the issue in Bug #52289
    "performance regression for MyISAM in sysbench OLTP_RW
    test".
    To emphasize above changes wake_up_waiters() was renamed
    to MDL_context::reschedule_waiters().
  - Changed code to add tickets for new requests to the back of
    waiters queue and to select tickets to be satisfied from
    the head of the queue if possible (this makes scheduling of
    requests with the same priority fair). To be able to do
    this efficiently we now use for waiting and granted queues
    version of I_P_List class which provides fast push_back()
    method.
  - Members and methods of MDL_context related to sending
    and waiting for signal were moved to separate MDL_wait
    class.
  - Since in order to avoid race conditions we must grant the
    lock only to the context which was not chosen as a victim
    of deadlock, killed or aborted due to timeout
    MDL_wait::set_status() (former awake()) was changed not to
    send signal if signal slot is already occupied and to
    indicate this fact through its return value. As another
    consequence MDL_wait::timed_wait() method was changed to
    handle timeout (optionally) and abort due to kill as
    signals which make signal slot occupied.
  - Renamed MDL_context::acquire_lock_impl() to acquire_lock().
    Changed it to be able correctly process requests for shared
    locks when there are open HANDLERs, made this method more
    optimized for acquisition of shared locks. As part of this
    change moved code common between try_acquire_lock() and
    acquire_lock() to new try_acquire_lock_impl() method.
    Also adjusted acquire_lock()'s code to take into account
    the fact that in cases when lock is granted as result of
    MDL_context::reschedule_waiters() call (i.e. when it is
    granted after waiting for lock conflict to go away)
    updating MDL_lock state is responsibility of the thread
    calling reschedule_waiters().
  - Changed MDL_context::find_deadlock() to send VICTIM
    signal even if victim is the context which has initiated
    deadlock detection. This is required in order to avoid
    races in cases when the same context simultaneously is
    chosen as a victim and its request for lock is satisfied.
    As result return value of this method became unnecessary
    and it was changed to return void.
    Adjusted MDL_lock::find_deadlock() method to take into
    account that now there can be a discrepancy between
    MDL_context::m_waiting_for value being set and real state
    of the ticket this member points to.
  - Renamed MDL_context::m_waiting_for_lock to m_LOCK_waiting_for
    and MDL_context::stop_waiting() to done_waiting_for().
  - Finally, removed MDL_context::wait_for_lock() method.
sql/mdl.h:
  Changed MDL subsystem to support new approach to acquring
  metadata locks in open tables and more fair and efficient
  scheduling of metadata locks. To implement this:
  - Members and methods of MDL_context related to sending
    and waiting for signal were moved to separate MDL_wait
    class.
  - Since now in order to avoid race conditions we must grant
    the lock only to the context which was not chosen as a
    victim of deadlock, killed or aborted due to timeout
    MDL_wait::set_status (former awake()) was changed not to
    send signal if signal slot is already occupied and to
    indicate this fact through its return value.
    Also NORMAL_WAKE_UP signal became GRANTED, and timeouts
    and aborts due to kill became full blown signals rather
    than simple return values.
  - MDL_wait::timed_wait() now takes extra parameter that
    indicates whether signal should be set if timeout is
    reached.
  - Enabled fast push_back() operation in MDL_context::m_tickets
    list to make move_ticket_after_trans_sentinel() method more
    efficient.
  - Removed MDL_context::wait_for_lock() method.
  - Renamed MDL_context::m_waiting_for_lock to m_LOCK_waiting_for
    and MDL_context::stop_waiting() to done_waiting_for().
  - MDL_context::acquire_lock_impl() became acquire_lock().
  - Introduced MDL_context::try_acquire_lock_impl() as a
    place for code shared by try_acquire_lock and
    acquire_lock().
  - Due to fact that now VICTIM signal is sent even if victim
    is the context which has initiated deadlock detection
    find_deadlock() no longer needs a return value.
sql/sql_base.cc:
  Implemented new approach to acquiring metadata locks in
  open_tables(). We no longer perform back-off when conflicting
  metadata lock is encountered. Instead we wait for this lock
  to go away while holding all locks which were acquired so
  far. Back-off is only used in situation when further waiting
  will cause a deadlock which could be avoided by performing
  back-off and restarting open_tables() process. Absence of
  waiting between back-off and restart of acquiring metadata
  locks can't lead to livelocks as MDL subsystem was changed
  to make release of lock and granting it to waiting lock
  an atomic action, so back-off will automatically give way
  to other participants of deadlock loop.
  Accordingly:
  - open_table_get_mdl_lock() and open_and_process_routine()
    were changed to wait for conflicting metadata lock to
    go away without back-off. Only if such wait leads to a
    deadlock back-off is requested. As part of this change
    new error handler class was introduced which converts,
    if possible, ER_LOCK_DEADLOCK error to a request for
    back-off and re-start of open_tables() process.
  - Open_table_context::recover_from_failed_open() was changed
    not to wait in case of metadata lock conflict. Instead we
    immediately proceed to re-acquiring locks.
  - Open_table_context::request_backoff_action() now always
    emits error if back-off is requested in the middle of
    transaction as we can't be sure that releasing lock
    which were acquired only by current statement will
    resolve a deadlock. Before this patch such situations were
    successfully detected thanks to the fact that we called
    MDL_context::wait_for_lock() method in
    recover_from_failed_open().
  - In order to avoid deadlocks open_tables() code was adjusted
    to flush open HANDLERs for which there are pending requests
    for X locks before restarting the process of acquiring
    metadata locks.
  - Changed close_tables_for_reopen() not to reset MDL_request
    for tables belonging to the tail of prelocking list. It is
    no longer necessary as these MDL_request objects won't be
    used for any waiting.
  - Adjusted comment in tdc_wait_for_old_version() to avoid
    mentioning removed MDL_context::wait_for_lock() method.
sql/sql_base.h:
  As we no longer wait for conflicting metadata lock away in
  Open_table_context::recover_from_failed_open() method,
  Open_table_context::OT_WAIT_MDL_LOCK action was renamed to
  OT_MDL_CONFLICT.
  Also Open_table_context::m_failed_mdl_request became
  unnecessary and was removed.
sql/sql_plist.h:
  Extended I_P_List template to support efficient push_back()
  operation if it is parameterized with an appropriate policy
  class.
sql/sql_show.cc:
  Adjusted code after removal of MDL_context::wait_for_lock()
  method. Now if one needs to acquire metadata lock with waiting
  one has to use a variant of MDL_context::acquire_lock() method.
2010-06-07 11:06:55 +04:00