condition variable per context instead of one mutex and one conditional
variable for the whole subsystem.
This should increase concurrency in this subsystem.
It also opens the way for further changes which are necessary to solve
such bugs as bug #46272 "MySQL 5.4.4, new MDL: unnecessary deadlock"
and bug #37346 "innodb does not detect deadlock between update and alter
table".
Two other notable changes done by this patch:
- MDL subsystem no longer implicitly acquires global intention exclusive
metadata lock when per-object metadata lock is acquired. Now this has
to be done by explicit calls outside of MDL subsystem.
- Instead of using separate MDL_context for opening system tables/tables
for purposes of I_S we now create MDL savepoint in the main context
before opening tables and rollback to this savepoint after closing
them. This means that it is now possible to get ER_LOCK_DEADLOCK error
even not inside a transaction. This might happen in unlikely case when
one runs DDL on one of system tables while also running DDL on some
other tables. Cases when this ER_LOCK_DEADLOCK error is not justified
will be addressed by advanced deadlock detector for MDL subsystem which
we plan to implement.
This change is supposed to reduce number of ER_LOCK_DEADLOCK
errors which occur when multi-statement transaction encounters
conflicting metadata lock in cases when waiting is possible.
The idea is not to fail ER_LOCK_DEADLOCK error immediately when
we encounter conflicting metadata lock. Instead we release all
metadata locks acquired by current statement and start to wait
until conflicting lock go away. To avoid deadlocks we use simple
empiric which aborts waiting with ER_LOCK_DEADLOCK error if it
turns out that somebody is waiting for metadata locks owned by
this transaction.
This patch also fixes bug #46273 "MySQL 5.4.4 new MDL: Bug#989
is not fully fixed in case of ALTER".
The bug was that concurrent execution of UPDATE or MULTI-UPDATE
statement as a part of multi-statement transaction that already
has used table being updated and ALTER TABLE statement might have
resulted of loss of isolation between this transaction and ALTER
TABLE statement, which manifested itself as changes performed by
ALTER TABLE becoming visible in transaction and wrong binary log
order as a consequence.
This problem occurred when UPDATE or MULTI-UPDATE's wait in
mysql_lock_tables() call was aborted due to metadata lock
upgrade performed by concurrent ALTER TABLE. After such abort all
metadata locks held by transaction were released but transaction
silently continued to be executed as if nothing has happened.
We solve this problem by changing our code not to release all
locks in such case. Instead we release only locks which were
acquired by current statement and then try to reacquire them
by restarting open/lock tables process. We piggyback on simple
deadlock detector implementation since this change has to be
done anyway for it.
3655 Jon Olav Hauglid 2009-10-19
Bug #30977 Concurrent statement using stored function and DROP FUNCTION
breaks SBR
Bug #48246 assert in close_thread_table
Implement a fix for:
Bug #41804 purge stored procedure cache causes mysterious hang for many
minutes
Bug #49972 Crash in prepared statements
The problem was that concurrent execution of DML statements that
use stored functions and DDL statements that drop/modify the same
function might result in incorrect binary log in statement (and
mixed) mode and therefore break replication.
This patch fixes the problem by introducing metadata locking for
stored procedures and functions. This is similar to what is done
in Bug#25144 for views. Procedures and functions now are
locked using metadata locks until the transaction is either
committed or rolled back. This prevents other statements from
modifying the procedure/function while it is being executed. This
provides commit ordering - guaranteeing serializability across
multiple transactions and thus fixes the reported binlog problem.
Note that we do not take locks for top-level CALLs. This means
that procedures called directly are not protected from changes by
simultaneous DDL operations so they are executed at the state they
had at the time of the CALL. By not taking locks for top-level
CALLs, we still allow transactions to be started inside
procedures.
This patch also changes stored procedure cache invalidation.
Upon a change of cache version, we no longer invalidate the entire
cache, but only those routines which we use, only when a statement
is executed that uses them.
This patch also changes the logic of prepared statement validation.
A stored procedure used by a prepared statement is now validated
only once a metadata lock has been acquired. A version mismatch
causes a flush of the obsolete routine from the cache and
statement reprepare.
Incompatible changes:
1) ER_LOCK_DEADLOCK is reported for a transaction trying to access
a procedure/function that is locked by a DDL operation in
another connection.
2) Procedure/function DDL operations are now prohibited in LOCK
TABLES mode as exclusive locks must be taken all at once and
LOCK TABLES provides no way to specifiy procedures/functions to
be locked.
Test cases have been added to sp-lock.test and rpl_sp.test.
Work on this bug has very much been a team effort and this patch
includes and is based on contributions from Davi Arnaut, Dmitry
Lenev, Magne Mæhre and Konstantin Osipov.
"HANDLER statements within a transaction might lead to deadlocks".
Introduce a notion of a sentinel to MDL_context. A sentinel
is a ticket that separates all tickets in the context into two
groups: before and after it. Currently we can have (and need) only
one designated sentinel -- it separates all locks taken by LOCK
TABLE or HANDLER statement, which must survive COMMIT and ROLLBACK
and all other locks, which must be released at COMMIT or ROLLBACK.
The tricky part is maintaining the sentinel up to date when
someone release its corresponding ticket. This can happen, e.g.
if someone issues DROP TABLE under LOCK TABLES (generally,
see all calls to release_all_locks_for_name()).
MDL_context::release_ticket() is modified to take care of it.
******
A fix and a test case for Bug#46224 "HANDLER statements within a
transaction might lead to deadlocks".
An attempt to mix HANDLER SQL statements, which are transaction-
agnostic, an open multi-statement transaction,
and DDL against the involved tables (in a concurrent connection)
could lead to a deadlock. The deadlock would occur when
HANDLER OPEN or HANDLER READ would have to wait on a conflicting
metadata lock. If the connection that issued HANDLER statement
also had other metadata locks (say, acquired in scope of a
transaction), a classical deadlock situation of mutual wait
could occur.
Incompatible change: entering LOCK TABLES mode automatically
closes all open HANDLERs in the current connection.
Incompatible change: previously an attempt to wait on a lock
in a connection that has an open HANDLER statement could wait
indefinitely/deadlock. After this patch, an error ER_LOCK_DEADLOCK
is produced.
The idea of the fix is to merge thd->handler_mdl_context
with the main mdl_context of the connection, used for transactional
locks. This makes deadlock detection possible, since all waits
with locks are "visible" and available to analysis in a single
MDL context of the connection.
Since HANDLER locks and transactional locks have a different life
cycle -- HANDLERs are explicitly open and closed, and so
are HANDLER locks, explicitly acquired and released, whereas
transactional locks "accumulate" till the end of a transaction
and are released only with COMMIT, ROLLBACK and ROLLBACK TO SAVEPOINT,
a concept of "sentinel" was introduced to MDL_context.
All locks, HANDLER and others, reside in the same linked list.
However, a selected element of the list separates locks with
different life cycle. HANDLER locks always reside at the
end of the list, after the sentinel. Transactional locks are
prepended to the beginning of the list, before the sentinel.
Thus, ROLLBACK, COMMIT or ROLLBACK TO SAVEPOINT, only
release those locks that reside before the sentinel. HANDLER locks
must be released explicitly as part of HANDLER CLOSE statement,
or an implicit close.
The same approach with sentinel
is also employed for LOCK TABLES locks. Since HANDLER and LOCK TABLES
statement has never worked together, the implementation is
made simple and only maintains one sentinel, which is used either
for HANDLER locks, or for LOCK TABLES locks.
Bug#42546 Backup: RESTORE fails, thinking it finds an existing table
The problem occured when a MDL locking conflict happened for a non-existent
table between a CREATE and a INSERT statement. The code for CREATE
interpreted this lock conflict to mean that the table existed,
which meant that the statement failed when it should not have.
The problem could occur for CREATE TABLE, CREATE TABLE LIKE and
ALTER TABLE RENAME.
This patch fixes the problem for CREATE TABLE and CREATE TABLE LIKE.
It is based on code backported from the mysql-6.1-fk tree written
by Dmitry Lenev. CREATE now uses normal open_and_lock_tables() code
to acquire exclusive locks. This means that for the test case in the bug
description, CREATE will wait until INSERT completes so that it can
get the exclusive lock. This resolves the reported bug.
The patch also prohibits CREATE TABLE and CREATE TABLE LIKE under
LOCK TABLES. Note that this is an incompatible change and must
be reflected in the documentation. Affected test cases have been
updated.
mdl_sync.test contains tests for CREATE TABLE and CREATE TABLE LIKE.
Fixing the issue for ALTER TABLE RENAME is beyond the scope of this
patch. ALTER TABLE cannot be prohibited from working under LOCK TABLES
as this could seriously impact customers and a proper fix would require
a significant rewrite.
------------------------------------------------------------
revno: 2617.68.7
committer: Dmitry Lenev <dlenev@mysql.com>
branch nick: mysql-next-bg46044
timestamp: Thu 2009-08-27 10:22:17 +0400
message:
Fix for bug #46044 "MDL deadlock on LOCK TABLE + CREATE TABLE HIGH_PRIORITY
FOR UPDATE".
Deadlock occured when during execution of query to I_S we tried to open
a table or its .FRM in order to get information about it and had to wait
because we have encountered exclusive metadata lock on this table held by
a DDL operation from another connection which in its turn waited for some
resource currently owned by connection executing this I_S query.
For example, this might have happened if one under LOCK TABLES executed I_S
query targeted to particular table (which was not among locked) and also
concurrently tried to create this table using CREATE TABLE SELECT which
had to wait for one of tables locked by the first connection.
Another situation in which deadlock might have occured is when I_S query,
which was executed as part of transaction, tried to get information about
table which just has been dropped by concurrent DROP TABLES executed under
LOCK TABLES and this DROP TABLES for its completion also had to wait
transaction from the first connection.
This problem stemmed from the fact that opening of tables/.FRMs for I_S
filling is happening outside of connection's main MDL_context so code
which tries to detect deadlocks due to conflicting metadata locks doesn't
work in this case. Indeed, this led to deadlocks when during I_S filling
we tried to wait for conflicting metadata lock to go away, while its owner
was waiting for some resource held by connection executing I_S query.
This patch solves this problem by avoiding waiting in such situation.
Instead we skip this table and produce warning that information about
it was omitted from I_S due to concurrent DDL operation. We still wait
for conflicting metadata lock to go away when it is known that deadlock
is not possible (i.e. when connection executing I_S query does not hold
any metadata or table-level locks).
Basically, we apply our standard deadlock avoidance technique for metadata
locks to the process of filling of I_S tables but replace ER_LOCK_DEADLOCK
error with a warning.
Note that this change is supposed to be safe for 'mysqldump' since the
only its mode which is affected by this change is --single-transaction mode
is not safe in the presence of concurrent DDL anyway (and this fact is
documented). Other modes are unaffected because they either use
SHOW TABLES/SELECT * FROM I_S.TABLE_NAMES which do not take any metadata
locks in the process of I_S table filling and thus cannot skip tables or
execute I_S queries for tables which were previously locked by LOCK TABLES
(or in the presence of global read lock) which excludes possibility of
encountering conflicting metadata lock.
----------------------------------------------------------
revno: 2617.69.25
committer: Konstantin Osipov <kostja@sun.com>
branch nick: 5.4-42546
timestamp: Fri 2009-08-14 23:52:00 +0400
message:
A cleanup in open_tables() and lock_tables():
change return type of these functions to bool from int,
to follow convention in the rest of the code.
(Part of WL#4284 review fixes).
----------------------------------------------------------
revno: 2617.69.24
committer: Konstantin Osipov <kostja@sun.com>
branch nick: 5.4-42546
timestamp: Fri 2009-08-14 19:22:05 +0400
message:
A pre-requisite for a fix for Bug#42546 "Backup: RESTORE fails, thinking it
finds an existing table"
Back-port from WL 148 "Foreign keys" feature tree a patch
that introduced Prelocking_strategy class -- a way to parameterize
open_tables() behaviour, implemented by Dmitry Lenev.
(Part of WL#4284).
----------------------------------------------------------
revno: 2617.69.20
committer: Konstantin Osipov <kostja@sun.com>
branch nick: 5.4-4284-1-assert
timestamp: Thu 2009-08-13 18:29:55 +0400
message:
WL#4284 "Transactional DDL locking"
A review fix.
Since WL#4284 implementation separated MDL_request and MDL_ticket,
MDL_request becamse a utility object necessary only to get a ticket.
Store it by-value in TABLE_LIST with the intent to merge
MDL_request::key with table_list->table_name and table_list->db
in future.
Change the MDL subsystem to not require MDL_requests to
stay around till close_thread_tables().
Remove the list of requests from the MDL context.
Requests for shared metadata locks acquired in open_tables()
are only used as a list in recover_from_failed_open_table_attempt(),
which calls mdl_context.wait_for_locks() for this list.
To keep such list for recover_from_failed_open_table_attempt(),
introduce a context class (Open_table_context), that collects
all requests.
A lot of minor cleanups and simplications that became possible
with this change.
------------------------------------------------------------
revno: 2617.65.6
committer: Dmitry Lenev <dlenev@mysql.com>
branch nick: mysql-azalea-bg39674
timestamp: Sat 2009-07-25 00:28:43 +0400
message:
Fix for bug #39674 "On shutdown mdl_destroy() called before
plugin_shutdown()".
Attempt to shutdown PBXT engine plugin led to assertion failure
caused by using already destroyed mutex in metadata locking
subsystem.
This problem stemmed from the fact that we MDL subsystem and
table definition cache were deinitialized before plugin shutdown
while PBXT plugin during its shutdown process accessed tables and
therefore expected them to be in working shape.
This patch solves this problem by moving deinitialization of
these two subsystems after plugins are shut down.
No test case is provided since such test case would require
using PBXT or other plugin which accesses tables during its
shutdown process.
2617.31.12, 2617.31.15, 2617.31.15, 2617.31.16, 2617.43.1
- initial changeset that introduced the fix for
Bug#989 and follow up fixes for all test suite failures
introduced in the initial changeset.
------------------------------------------------------------
revno: 2617.31.1
committer: Davi Arnaut <Davi.Arnaut@Sun.COM>
branch nick: 4284-6.0
timestamp: Fri 2009-03-06 19:17:00 -0300
message:
Bug#989: If DROP TABLE while there's an active transaction, wrong binlog order
WL#4284: Transactional DDL locking
Currently the MySQL server does not keep metadata locks on
schema objects for the duration of a transaction, thus failing
to guarantee the integrity of the schema objects being used
during the transaction and to protect then from concurrent
DDL operations. This also poses a problem for replication as
a DDL operation might be replicated even thought there are
active transactions using the object being modified.
The solution is to defer the release of metadata locks until
a active transaction is either committed or rolled back. This
prevents other statements from modifying the table for the
entire duration of the transaction. This provides commitment
ordering for guaranteeing serializability across multiple
transactions.
- Incompatible change:
If MySQL's metadata locking system encounters a lock conflict,
the usual schema is to use the try and back-off technique to
avoid deadlocks -- this schema consists in releasing all locks
and trying to acquire them all in one go.
But in a transactional context this algorithm can't be utilized
as its not possible to release locks acquired during the course
of the transaction without breaking the transaction commitments.
To avoid deadlocks in this case, the ER_LOCK_DEADLOCK will be
returned if a lock conflict is encountered during a transaction.
Let's consider an example:
A transaction has two statements that modify table t1, then table
t2, and then commits. The first statement of the transaction will
acquire a shared metadata lock on table t1, and it will be kept
utill COMMIT to ensure serializability.
At the moment when the second statement attempts to acquire a
shared metadata lock on t2, a concurrent ALTER or DROP statement
might have locked t2 exclusively. The prescription of the current
locking protocol is that the acquirer of the shared lock backs off
-- gives up all his current locks and retries. This implies that
the entire multi-statement transaction has to be rolled back.
- Incompatible change:
FLUSH commands such as FLUSH PRIVILEGES and FLUSH TABLES WITH READ
LOCK won't cause locked tables to be implicitly unlocked anymore.
------------------------------------------------------------
revno: 2630.22.3
committer: Davi Arnaut <Davi.Arnaut@Sun.COM>
branch nick: 4284-6.0
timestamp: Thu 2008-08-07 22:33:43 -0300
message:
WL#4284: Transactional DDL locking
Make transaction management more modular through a new interface.
The overall objective of this change is to provide groundwork
for the design of transactional DDL locking by cleaning up the
transaction high level API to better distinguish operations implicit
and explicit, and single statement transaction from operations on
the normal transaction.
Having a a high-level interface for transaction management provides
a better base for implementing transactional concepts that are not
always tied to storage engines and also makes it easier to interect
with other higher level modules of the server.
------------------------------------------------------------
revno: 2630.13.16
committer: Davi Arnaut <Davi.Arnaut@Sun.COM>
branch nick: WL#4284
timestamp: Sat 2008-07-26 13:38:20 -0300
message:
WL#4284: Transactional DDL locking
SQL statements' effect on transactions.
Currently the MySQL server and its storage engines are not
capable of rolling back operations that define or modify data
structures (also known as DDL statements) or operations that
alter any of the system tables (the mysql database). Allowing
these group of statements to participate in transactions
is unfeasible at this time (since rollback has no effect
whatsoever on them) and goes against the design of our metadata
locking subsystem.
The solution is to issue implicit commits before and after
those statements execution. This effectively confines each of
those statements to its own special transaction and ensures
that metadata locks taken during this special transaction
are not leaked into posterior statements/transactions.
----------------------------------------------------------
revno: 2630.4.38
committer: Konstantin Osipov <konstantin@mysql.com>
branch nick: mysql-6.0-4144
timestamp: Wed 2008-06-25 22:07:06 +0400
message:
WL#4144 - Lock MERGE engine children.
Committing a version of the patch merged with WL#3726
on behalf of Ingo.
Step #1: Move locking from parent to children.
MERGE children are now left in the query list of tables
after inserted there in open_tables(). So they are locked
by lock_tables() as all other tables are.
The MERGE parent does not store locks any more. It appears
in a MYSQL_LOCK with zero lock data. This is kind of a "dummy"
lock.
All other lock handling is also done directly on the children.
To protect against parent or child modifications during LOCK
TABLES, the children are detached after every statement and
attached before every statement, even under LOCK TABLES.
The children table list is removed from the query list of tables
on every detach and on close of the parent.
Step #2: Move MERGE specific functionality from SQL layer
into table handler.
Functionality moved from SQL layer (mainly sql_base.cc)
to the table handler (ha_myisammrg.cc).
Unnecessary code is removed from the SQL layer.
Step #3: Moved all MERGE specific members from TABLE
to ha_myisammrg.
Moved members from TABLE to ha_myisammrg.
Renamed some mebers.
Fixed comments.
Step #4: Valgrind and coverage testing
Valgrind did not uncover new problems.
Added purecov comments.
Added a new test for DATA/INDEX DIRECTORY options.
Changed handling of ::reset() for non-attached children.
Fixed the merge-big test.
Step #5: Fixed crashes detected during review
Changed detection when to attach/detach.
Added new tests.
Backport also the fix for Bug#44040 "MySQL allows creating a
MERGE table upon VIEWs but crashes when using it"
------------------------------------------------------------
revno: 2630.4.33
committer: Dmitry Lenev <dlenev@mysql.com>
branch nick: mysql-6.0-3726-w2
timestamp: Fri 2008-06-20 17:11:20 +0400
message:
WL#3726 "DDL locking for all metadata objects".
After-review fixes in progress.
Minimized dependency of mdl.cc on other modules (particularly
made it independant of mysql_priv.h) in order to be able
write unit tests for metadata locking subsystem.
----------------------------------------------------------
revno: 2630.10.1
committer: Konstantin Osipov <konstantin@mysql.com>
branch nick: mysql-6.0-lock-tables-tidyup
timestamp: Wed 2008-06-11 15:49:58 +0400
message:
WL#3726, review fixes.
Now that we have metadata locks, we don't need to keep a crippled
TABLE instance in the table cache to indicate that a table is locked.
Remove all code that used this technique. Instead, rely on metadata
locks and use the standard open_table() and close_thread_table()
to manipulate with the table cache tables.
Removes a list of functions that have become unused (see the comment
for sql_base.cc for details).
Under LOCK TABLES, keep a TABLE_LIST instance for each table
that may be temporarily closed. For that, implement an own class for
LOCK TABLES mode, Locked_tables_list.
This is a pre-requisite patch for WL#4144.
This is not exactly a backport: there is no new
online ALTER table in Celosia, so the old alter table
code was changed to work with the new table cache API.
------------------------------------------------------------
revno: 2630.9.3
committer: Dmitry Lenev <dlenev@mysql.com>
branch nick: mysql-6.0-3726-w3
timestamp: Wed 2008-06-11 08:33:36 +0400
message:
WL#3726 "DDL locking for all metadata objects".
After review fixes in progress.
Changed close_cached_tables() not to flush all unused TABLE
instances when flushing individual table.
Renamed expel_table_from_cache() to tdc_remove_table() and
added enum parameter to be able more explicitly specify type
of removal, rewrote its code to be more efficient.
******
Backport of:
------------------------------------------------------------
revno: 2630.9.4
committer: Dmitry Lenev <dlenev@mysql.com>
branch nick: mysql-6.0-3726-w3
timestamp: Wed 2008-06-11 15:53:53 +0400
message:
WL#3726 "DDL locking for all metadata objects".
After-review fixes in progress.
Minor changes in order to improve code readability
and simplify debugging.
Text conflict in mysql-test/collections/default.experimental
Text conflict in mysql-test/r/show_check.result
Text conflict in mysql-test/r/sp-code.result
Text conflict in mysql-test/suite/binlog/r/binlog_tmp_table.result
Text conflict in mysql-test/suite/rpl/t/disabled.def
Text conflict in mysql-test/t/show_check.test
Text conflict in mysys/my_delete.c
Text conflict in sql/item.h
Text conflict in sql/item_cmpfunc.h
Text conflict in sql/log.cc
Text conflict in sql/mysqld.cc
Text conflict in sql/repl_failsafe.cc
Text conflict in sql/slave.cc
Text conflict in sql/sql_parse.cc
Text conflict in sql/sql_table.cc
Text conflict in sql/sql_yacc.yy
Text conflict in storage/myisam/ha_myisam.cc
Corrected results for
stm_auto_increment_bug33029.reject 2009-12-01
20:01:49.000000000 +0300
<andrei> @@ -42,9 +42,6 @@
<andrei> RETURN i;
<andrei> END//
<andrei> CALL p1();
<andrei> -Warnings:
<andrei> -Note 1592 Statement may not be safe to log in statement
format.
<andrei> -Note 1592 Statement may not be safe to log in statement
format.
There should be indeed no Note present because there is in fact autoincrement
top-level query in sp() that triggers inserting in yet another auto-inc table.
(todo: alert DaoGang to improve the test).
------------------------------------------------------------
revno: 2630.4.27
committer: Dmitry Lenev <dlenev@mysql.com>
branch nick: mysql-6.0-3726-w2
timestamp: Mon 2008-06-09 14:01:19 +0400
message:
WL#3726 "DDL locking for all metadata objects".
After review fixes in progress.
Changed open_table() to return bool. This allows more easily to
distinguish cases when this function succeeds but returns no TABLE
instance (in case of view or in case of special kind of open) from
cases when we have an error. Pointer to TABLE instance is now
always returned in TABLE_LIST::table member.
This change allows to get rid of false assumption in open_tables()
implementation and makes it more clear.
------------------------------------------------------------
revno: 2630.4.20
committer: Dmitry Lenev <dlenev@mysql.com>
branch nick: mysql-6.0-3726-w2
timestamp: Wed 2008-06-04 16:27:06 +0400
message:
WL#3726 "DDL locking for all metadata objects"
After review fixes in progress.
Got rid of TABLE_LIST::mdl_upgradable member and related functions
by using special flag which to be passed to open_table() which
asks it to take upgradable metadata lock on table being opened.
---------------------------------------------
2630.7.3 Konstantin Osipov 2008-06-02
Various style changes preceding the removal of reopen_table().
(Post-review fixes for WL#3726).
------------------------------------------------------------
revno: 2630.4.16
committer: Dmitry Lenev <dlenev@mysql.com>
branch nick: mysql-6.0-3726-w
timestamp: Thu 2008-05-29 09:45:02 +0400
message:
WL#3726 "DDL locking for all metadata objects".
After review changes in progress.
Tweaked some comments and did some renames to
avoid ambiguites.
------------------------------------------------------------
revno: 2630.4.14
committer: Dmitry Lenev <dlenev@mysql.com>
branch nick: mysql-6.0-3726-w
timestamp: Wed 2008-05-28 12:16:03 +0400
message:
WL#3726 "DDL locking for all metadata objects".
After review fixes in progress. Removed unused code and
adjusted names of functions/methods to better reflect
their current function.
------------------------------------------------------------
revno: 2630.4.13
committer: Dmitry Lenev <dlenev@mysql.com>
branch nick: mysql-6.0-3726-w
timestamp: Wed 2008-05-28 12:07:30 +0400
message:
WL#3726 "DDL locking for all metadata objects".
After review fixes in progress.
Get rid of remove_table_from_cache() function since it was
doing two things at once -- waiting while no one uses particular
table (now job of metadata locking) and removing TABLE/TABLE_SHARE
instances from table definition cache (now job of
expel_table_from_cache()).
------------------------------------------------------------
revno: 2630.6.1
committer: Konstantin Osipov <konstantin@mysql.com>
branch nick: mysql-6.0-3726
timestamp: Tue 2008-05-27 13:45:34 +0400
message:
Remove an unused argument from release_table_share().
Remove unused members from TABLE_SHARE struct.
Review comments in scope of WL#3726 "DDL locking for all metadata
objects"
------------------------------------------------------------
revno: 2630.4.11
committer: Dmitry Lenev <dlenev@mysql.com>
branch nick: mysql-6.0-3726-w
timestamp: Tue 2008-05-27 21:31:53 +0400
message:
WL#3726 "DDL locking for all metadata objects".
After review fixes in progress.
Changed mysql_lock_tables() to be no longer responsible for
reopening table if waiting for the lock on it was aborted.
This allows to get rid of several annoying functions.
Backport of:
------------------------------------------------------------
revno: 2630.4.1
committer: Dmitry Lenev <dlenev@mysql.com>
branch nick: mysql-6.0-3726-w
timestamp: Fri 2008-05-23 17:54:03 +0400
message:
WL#3726 "DDL locking for all metadata objects".
After review fixes in progress.
------------------------------------------------------------
This is the first patch in series. It transforms the metadata
locking subsystem to use a dedicated module (mdl.h,cc). No
significant changes in the locking protocol.
The import passes the test suite with the exception of
deprecated/removed 6.0 features, and MERGE tables. The latter
are subject to a fix by WL#4144.
Unfortunately, the original changeset comments got lost in a merge,
thus this import has its own (largely insufficient) comments.
This patch fixes Bug#25144 "replication / binlog with view breaks".
Warning: this patch introduces an incompatible change:
Under LOCK TABLES, it's no longer possible to FLUSH a table that
was not locked for WRITE.
Under LOCK TABLES, it's no longer possible to DROP a table or
VIEW that was not locked for WRITE.
******
Backport of:
------------------------------------------------------------
revno: 2630.4.2
committer: Dmitry Lenev <dlenev@mysql.com>
branch nick: mysql-6.0-3726-w
timestamp: Sat 2008-05-24 14:03:45 +0400
message:
WL#3726 "DDL locking for all metadata objects".
After review fixes in progress.
******
Backport of:
------------------------------------------------------------
revno: 2630.4.3
committer: Dmitry Lenev <dlenev@mysql.com>
branch nick: mysql-6.0-3726-w
timestamp: Sat 2008-05-24 14:08:51 +0400
message:
WL#3726 "DDL locking for all metadata objects"
Fixed failing Windows builds by adding mdl.cc to the lists
of files needed to build server/libmysqld on Windows.
******
Backport of:
------------------------------------------------------------
revno: 2630.4.4
committer: Dmitry Lenev <dlenev@mysql.com>
branch nick: mysql-6.0-3726-w
timestamp: Sat 2008-05-24 21:57:58 +0400
message:
WL#3726 "DDL locking for all metadata objects".
Fix for assert failures in kill.test which occured when one
tried to kill ALTER TABLE statement on merge table while it
was waiting in wait_while_table_is_used() for other connections
to close this table.
These assert failures stemmed from the fact that cleanup code
in this case assumed that temporary table representing new
version of table was open with adding to THD::temporary_tables
list while code which were opening this temporary table wasn't
always fulfilling this.
This patch changes code that opens new version of table to
always do this linking in. It also streamlines cleanup process
for cases when error occurs while we have new version of table
open.
******
WL#3726 "DDL locking for all metadata objects"
Add libmysqld/mdl.cc to .bzrignore.
******
Backport of:
------------------------------------------------------------
revno: 2630.4.6
committer: Dmitry Lenev <dlenev@mysql.com>
branch nick: mysql-6.0-3726-w
timestamp: Sun 2008-05-25 00:33:22 +0400
message:
WL#3726 "DDL locking for all metadata objects".
Addition to the fix of assert failures in kill.test caused by
changes for this worklog.
Make sure we close the new table only once.
The following 6.0 revisions were analyzed:
- sp1r-brian@zim.(none)-20071228102738-21894
- sp1r-brian@zim.(none)-20071228121841-56447
- sp1r-brian@zim.(none)-20071228205403-56423
- sp1r-brian@zim.(none)-20071228221139-55341
- sp1r-brian@zim.(none)-20071228233443-55352
- sp1r-brian@zim.(none)-20071229094527-61763
- sp1r-brian@zim.(none)-20071230203739-61746
- sp1r-brian@zim.(none)-20080102213805-61741
- sp1r-brian@zim.(none)-20080103201041-61746
- sp1r-brian@zim.(none)-20080104234927-59875
- sp1r-brian@zim.(none)-20080105005827-59874
- sp1r-brian@zim.(none)-20080105012020-59865
- sp1r-brian@zim.(none)-20080106003858-59857
- sp1r-brian@zim.(none)-20080123195552-31680
- sp1r-brian@zim.(none)-20080124201848-29999
- sp1r-brian@zim.(none)-20080129075144-36991
- sp1r-cbell/Chuck@mysql_cab_desk.-20080215041806-21954
- sp1r-vvaintroub@wva.-20080212124547-06272
- sp1r-dfischer/mysqldev@mysql.com/production.mysql.com-20071223184258-15140
- sp1r-brian@zim.(none)-20080206122216-35774
- sp1r-baker@bk-internal.mysql.com-20080209005622-35947
- sp1r-baker@bk-internal.mysql.com-20080224215608-24613
- sp1r-baker@bk-internal.mysql.com-20080307170710-63543
- sp1r-baker@bk-internal.mysql.com-20080312233205-13069
- sp1r-Reggie@core.-20080402175211-28643
- kpettersson@mysql.com-20080901101150-4ne74r8v0492vv42
- alik@sun.com-20090805173811-9fzt0ymcp9tsvn7k
- alik@sun.com-20090805173937-fcv1fdveodq5x9gb
- alik@sun.com-20090805175009-g1od16i3t1xkw2qr
- kostja@sun.com-20090805200643-j9i4fy7ii8ijho5c
- alik@sun.com-20090807195303-j4fb5m4l1dgdahwo
- alik@sun.com-20090808114848-3rkzr9kifrijzaqy
- alik@sun.com-20090810041739-ugmx34h34uid8mox
- alik@sun.com-20090810105306-rf43rfyzzblsy5e7
- alik@sun.com-20090810123113-ccdjwai68b5woqdm
- alik@sun.com-20090811080423-gb7pibec1znaydzy
- alik@sun.com-20090811082130-5uckar1vx3kdsw7g
- alik@sun.com-20090812202051-uqkfwwxxcjvo5ean
The following bugfixes are also backported within this patch:
- Bug#34292: netdb.h missing in hostname.cc
- Bug#39153: Failing to lookup a host name can lead to crash
in current IPv6 implementation
- Bug#38247: Server does not resolve connecting ip's
- Bug#43006: main.skip_name_resolve fails on Windows in PB2
- Bug#45606: ACL requires IPv4-mapped addresses to be used
- Bug#45584: Host name cache does not work as a cache
-------------------------------------------------------------
revno: 2877
committer: Davi Arnaut <Davi.Arnaut@Sun.COM>
branch nick: 35164-6.0
timestamp: Wed 2008-10-15 19:53:18 -0300
message:
Bug#35164: Large number of invalid pthread_attr_setschedparam calls
Bug#37536: Thread scheduling causes performance degradation at low thread count
Bug#12702: Long queries take 100% of CPU and freeze other applications under Windows
The problem is that although having threads with different priorities
yields marginal improvements [1] in some platforms [2], relying on some
statically defined priorities (QUERY_PRIOR and WAIT_PRIOR) to play well
(or to work at all) with different scheduling practices and disciplines
is, at best, a shot in the dark as the meaning of priority values may
change depending on the scheduling policy set for the process.
Another problem is that increasing priorities can hurt other concurrent
(running on the same hardware) applications (such as AMP) by causing
starvation problems as MySQL threads will successively preempt lower
priority processes. This can be evidenced by Bug#12702.
The solution is to not change the threads priorities and rely on the
system scheduler to perform its job. This also enables a system admin
to increase or decrease the scheduling priority of the MySQL process,
if intended.
Furthermore, the internal wrappers and code for changing the priority
of threads is being removed as they are now unused and ancient.
1. Due to unintentional side effects. On Solaris this could artificially
help benchmarks as calling the priority changing syscall millions of
times is more beneficial than the actual setting of the priority.
2. Where it actually works. It has never worked on Linux as the default
scheduling policy SCHED_OTHER only accepts the static priority 0.
Correction of backport patch:
* Fixed signature of check_access_table() for embedded build
* Fixed typo for last argument in a check_access() call from UINT_MAX to 0.
# Bug#24690 Stored functions: RETURNing UTF8 strings
# do not return UTF8_UNICODE_CI collation
#
# Bug#17903: cast to char results in binary
# Regression. The character set was not being properly initialized
# for CAST() with a type like CHAR(2) BINARY, which resulted in
# incorrect results or even a server crash.
#
Backporting from mysql-6.0-codebase.
mysql-test/r/sp-ucs2.result:
mysql-test/t/sp-ucs2.test:
Adding tests
sql/mysql_priv.h:
Adding prototype
sql/sp.cc
Remember COLLATE clause for non-default collations
sql/sql_parse.cc
Adding a new helper function
sql/sql_yacc.yy
- Allow "CHARACTER SET cs COLLATE cl" in
SP parameters, RETURNS, DECLARE
- Minor reorganization for "ASCII" and "UNICODE"
related rules, to make the code more readable,
also to allow these aliases:
* "VARCHAR(10) ASCII BINARY" -> CHARACTER SET latin1 COLLATE latin1_bin
* "VARCHAR(10) BINARY ASCII" -> CHARACTER SET latin1 COLLATE latin1_bin
* "VARCHAR(10) UNICODE BINARY" -> CHARACTER SET ucs2 COLLATE ucs2_bin
* "VARCHAR(10) BINARY UNICODE" -> CHARACTER SET ucs2 COLLATE ucs2_bin
Previously these four aliases returned the error
"This version of MySQL does not yet support return value collation".
Note:
This patch allows "VARCHAR(10) CHARACTER SET cs COLLATE cl"
and the above four aliases.
"VARCHAR(10) COLLATE cl" is still not allowed
i.e. when COLLATE is given without CHARACTER SET.
If we want to support this, we need an architecture decision
which character set to use by default.
