In RBR, DDL statement will change binlog format to non row-based
format before it is binlogged, but the binlog format was not be
restored, and then manipulating a temporary table can not reset binlog
format to row-based format rightly. So that the manipulated statement
is binlogged with statement-based format.
To fix the problem, restore the state of binlog format after the DDL
statement is binlogged.
mysql-test/extra/rpl_tests/rpl_tmp_table_and_DDL.test:
Added the test file to verify if executing DDL statement before
trying to manipulate a temporary table causes row-based replication
to break with error 'table does not exist'.
mysql-test/suite/binlog/r/binlog_row_mix_innodb_myisam.result:
Correct the test result, all the above binlog event
should be row-based after the bug49132 is fixed IN RBR.
mysql-test/suite/ndb/r/ndb_tmp_table_and_DDL.result:
Test result for bug#49132 base on ndb engine.
mysql-test/suite/ndb/t/ndb_tmp_table_and_DDL.test:
Added the test file to verify if executing DDL statement before
trying to manipulate a temporary table causes row-based replication
to break with error 'table does not exist' base on ndb engine.
mysql-test/suite/rpl/r/rpl_tmp_table_and_DDL.result:
Test result for bug#49132 base on myisam engine.
mysql-test/suite/rpl/t/rpl_tmp_table_and_DDL.test:
Added the test file to verify if executing DDL statement before
trying to manipulate a temporary table causes row-based replication
to break with error 'table does not exist' base on myisam engine.
sql/event_db_repository.cc:
Added code to restore the state of binlog format after the DDL
statement is binlogged.
sql/events.cc:
Added code to restore the state of binlog format after the DDL
statement is binlogged.
sql/sp.cc:
Added code to restore the state of binlog format after the DDL
statement is binlogged.
sql/sql_acl.cc:
Added code to restore the state of binlog format after the DDL
statement is binlogged.
sql/sql_udf.cc:
Added code to restore the state of binlog format after the DDL
statement is binlogged.
In RBR, DDL statement will change binlog format to non row-based
format before it is binlogged, but the binlog format was not be
restored, and then manipulating a temporary table can not reset binlog
format to row-based format rightly. So that the manipulated statement
is binlogged with statement-based format.
To fix the problem, restore the state of binlog format after the DDL
statement is binlogged.
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.
mysql-test/include/handler.inc:
Adjusted handler_myisam.test and handler_innodb.test to the fact that
exclusive metadata locks on tables are now acquired according to
alphabetical order of fully qualified table names instead of order
in which tables are mentioned in statement.
mysql-test/r/handler_innodb.result:
Adjusted handler_myisam.test and handler_innodb.test to the fact that
exclusive metadata locks on tables are now acquired according to
alphabetical order of fully qualified table names instead of order
in which tables are mentioned in statement.
mysql-test/r/handler_myisam.result:
Adjusted handler_myisam.test and handler_innodb.test to the fact that
exclusive metadata locks on tables are now acquired according to
alphabetical order of fully qualified table names instead of order
in which tables are mentioned in statement.
mysql-test/r/mdl_sync.result:
Adjusted mdl_sync.test to the fact that exclusive metadata locks on
tables are now acquired according to alphabetical order of fully
qualified table names instead of order in which tables are mentioned
in statement.
mysql-test/t/mdl_sync.test:
Adjusted mdl_sync.test to the fact that exclusive metadata locks on
tables are now acquired according to alphabetical order of fully
qualified table names instead of order in which tables are mentioned
in statement.
sql/events.cc:
Instead of using separate MDL_context for opening system tables we now
create MDL savepoint in the main context before opening such tables
and rollback to this savepoint after closing them. To support this
change methods of THD responsible for saving/restoring open table
state were changed to use Open_tables_backup class which in addition
to Open_table_state has a member for this savepoint. As result code
opening/closing system tables was changed to use Open_tables_backup
instead of Open_table_state class as well.
sql/ha_ndbcluster.cc:
Since manipulations with open table state no longer install proxy
MDL_context it does not make sense to perform them in order to
satisfy assert in mysql_rm_tables_part2(). Removed them per agreement
with Cluster team. This has not broken test suite since scenario in
which deadlock can occur and assertion fails is not covered by tests.
sql/lock.cc:
MDL subsystem no longer implicitly acquires global intention exclusive
metadata lock when per-object exclusive metadata lock is acquired.
Now this has to be done by explicit calls outside of MDL subsystem.
sql/log.cc:
Instead of using separate MDL_context for opening system tables we now
create MDL savepoint in the main context before opening such tables
and rollback to this savepoint after closing them. To support this
change methods of THD responsible for saving/restoring open table
state were changed to use Open_tables_backup class which in addition
to Open_table_state has a member for this savepoint. As result code
opening/closing system tables was changed to use Open_tables_backup
instead of Open_table_state class as well.
sql/mdl.cc:
Changed metadata locking subsystem to use mutex per lock and condition
variable per context instead of one mutex and one conditional variable
for the whole subsystem.
Changed approach to handling of global metadata locks. Instead of
implicitly acquiring intention exclusive locks when user requests
per-object upgradeable or exclusive locks now we require them to be
acquired explicitly in the same way as ordinary metadata locks.
In fact global lock are now ordinary metadata locks in new GLOBAL
namespace.
To implement these changes:
- Removed LOCK_mdl mutex and COND_mdl condition variable.
- Introduced MDL_lock::m_mutex mutexes which protect individual lock
objects.
- Replaced mdl_locks hash with MDL_map class, which has hash for
MDL_lock objects as a member and separate mutex which protects this
hash. Methods of this class allow to find(), find_or_create() or
remove() MDL_lock objects in concurrency-friendly fashion (i.e.
for most common operation, find_or_create(), we don't acquire
MDL_lock::m_mutex while holding MDL_map::m_mutex. Thanks to MikaelR
for this idea and benchmarks!). Added three auxiliary members to
MDL_lock class (m_is_destroyed, m_ref_usage, m_ref_release) to
support this concurrency-friendly behavior.
- Introduced MDL_context::m_ctx_wakeup_cond condition variable to be
used for waiting until this context's pending request can be
satisfied or its thread has to perform actions to resolve potential
deadlock. Context which want to wait add ticket corresponding to the
request to an appropriate queue of waiters in MDL_lock object so
they can be noticed when other contexts change state of lock and be
awaken by them by signalling on MDL_context::m_ctx_wakeup_cond.
As consequence MDL_ticket objects has to be used for any waiting
in metadata locking subsystem including one which happens in
MDL_context::wait_for_locks() method.
Another consequence is that MDL_context is no longer copyable and
can't be saved/restored when working with system tables.
- Made MDL_lock an abstract class, which delegates specifying exact
compatibility matrix to its descendants. Added MDL_global_lock child
class for global lock (The old is_lock_type_compatible() method
became can_grant_lock() method of this class). Added MDL_object_lock
class to represent per-object lock (The old MDL_lock::can_grant_lock()
became its method). Choice between two classes happens based on MDL
namespace in MDL_lock::create() method.
- Got rid of MDL_lock::type member as its meaning became ambigous for
global locks.
- To simplify waking up of contexts waiting for lock split waiting queue
in MDL_lock class in two queues. One for pending requests for exclusive
(including intention exclusive) locks and another for requests for
shared locks.
- Added virtual wake_up_waiters() method to MDL_lock, MDL_global_lock and
MDL_object_lock classes which allows to wake up waiting contexts after
state of lock changes. Replaced old duplicated code with calls to this
method.
- Adjusted MDL_context::try_acquire_shared_lock()/exclusive_lock()/
global_shared_lock(), MDL_ticket::upgrade_shared_lock_to_exclusive_lock()
and MDL_context::release_ticket() methods to use MDL_map and
MDL_lock::m_mutex instead of single LOCK_mdl mutex and wake up
waiters according to the approach described above. The latter method
also was renamed to MDL_context::release_lock().
- Changed MDL_context::try_acquire_shared_lock()/exclusive_lock() and
release_lock() not to handle global locks. They are now supposed to
be taken explicitly like ordinary metadata locks.
- Added helper MDL_context::try_acquire_global_intention_exclusive_lock()
and acquire_global_intention_exclusive_lock() methods.
- Moved common code from MDL_context::acquire_global_shared_lock() and
acquire_global_intention_exclusive_lock() to new method -
MDL_context::acquire_lock_impl().
- Moved common code from MDL_context::try_acquire_shared_lock(),
try_acquire_global_intention_exclusive_lock()/exclusive_lock()
to MDL_context::try_acquire_lock_impl().
- Since acquiring of several exclusive locks can no longer happen under
single LOCK_mdl mutex the approach to it had to be changed. Now we do
it in one by one fashion. This is done in alphabetical order to avoid
deadlocks. Changed MDL_context::acquire_exclusive_locks() accordingly
(as part of this change moved code responsible for acquiring single
exclusive lock to new MDL_context::acquire_exclusive_lock_impl()
method).
- Since we no longer have single LOCK_mdl mutex which protects all
MDL_context::m_is_waiting_in_mdl members using these members to
determine if we have really awaken context holding conflicting
shared lock became inconvinient. Got rid of this member and changed
notify_shared_lock() helper function and process of acquiring
of/upgrading to exclusive lock not to rely on such information.
Now in MDL_context::acquire_exclusive_lock_impl() and
MDL_ticket::upgrade_shared_lock_to_exclusive_lock() we simply
re-try to wake up threads holding conflicting shared locks after
small time out.
- Adjusted MDL_context::can_wait_lead_to_deadlock() and
MDL_ticket::has_pending_conflicting_lock() to use per-lock
mutexes instead of LOCK_mdl. To do this introduced
MDL_lock::has_pending_exclusive_lock() method.
sql/mdl.h:
Changed metadata locking subsystem to use mutex per lock and condition
variable per context instead of one mutex and one conditional variable
for the whole subsystem. In order to implement this change:
- Added MDL_key::cmp() method to be able to sort MDL_key objects
alphabetically. Changed length fields in MDL_key class to uint16
as 16-bit is enough for length of any key.
- Changed MDL_ticket::get_ctx() to return pointer to non-const
object in order to be able to use MDL_context::awake() method
for such contexts.
- Got rid of unlocked versions of can_wait_lead_to_deadlock()/
has_pending_conflicting_lock() methods in MDL_context and
MDL_ticket. We no longer has single mutex which protects all
locks. Thus one always has to use versions of these methods
which acquire per-lock mutexes.
- MDL_request_list type of list now counts its elements.
- Added MDL_context::m_ctx_wakeup_cond condition variable to be used
for waiting until this context's pending request can be satisfied
or its thread has to perform actions to resolve potential deadlock.
Added awake() method to wake up context from such wait.
Addition of condition variable made MDL_context uncopyable.
As result we no longer can save/restore MDL_context when working
with system tables. Instead we create MDL savepoint before opening
those tables and rollback to it once they are closed.
- MDL_context::release_ticket() became release_lock() method.
- Added auxiliary MDL_context::acquire_exclusive_lock_impl() method
which does all necessary work to acquire exclusive lock on one object
but should not be used directly as it does not enforce any asserts
ensuring that no deadlocks are possible.
- Since we no longer need to know if thread trying to acquire exclusive
lock managed to wake up any threads having conflicting shared locks
(as, anyway, we will try to wake up such threads again shortly)
- MDL_context::m_is_waiting_in_mdl member became unnecessary and
notify_shared_lock() no longer needs to be friend of MDL_context.
Changed approach to handling of global metadata locks. Instead of
implicitly acquiring intention exclusive locks when user requests
per-object upgradeable or exclusive locks now we require them to be
acquired explicitly in the same way as ordinary metadata locks.
- Added new GLOBAL namespace for such locks.
- Added new type of lock to be requested MDL_INTENTION_EXCLISIVE.
- Added MDL_context::try_acquire_global_intention_exclusive_lock()
and acquire_global_intention_exclusive_lock() methods.
- Moved common code from MDL_context::acquire_global_shared_lock()
and acquire_global_intention_exclusive_lock() to new method -
MDL_context::acquire_lock_impl().
- Moved common code from MDL_context::try_acquire_shared_lock(),
try_acquire_global_intention_exclusive_lock()/exclusive_lock()
to MDL_context::try_acquire_lock_impl().
- Added helper MDL_context::is_global_lock_owner() method to be
able easily to find what kind of global lock this context holds.
- MDL_context::m_has_global_shared_lock became unnecessary as
global read lock is now represented by ordinary ticket.
- Removed assert in MDL_context::set_lt_or_ha_sentinel() which became
false for cases when we execute LOCK TABLES under global read lock
mode.
sql/mysql_priv.h:
Instead of using separate MDL_context for opening system tables we now
create MDL savepoint in the main context before opening such tables
and rollback to this savepoint after closing them. To support this
change methods of THD responsible for saving/restoring open table
state were changed to use Open_tables_backup class which in addition
to Open_table_state has a member for this savepoint. As result calls
opening/closing system tables were changed to use Open_tables_backup
instead of Open_table_state class as well.
sql/sp.cc:
Instead of using separate MDL_context for opening system tables we now
create MDL savepoint in the main context before opening such tables
and rollback to this savepoint after closing them. To support this
change methods of THD responsible for saving/restoring open table
state were changed to use Open_tables_backup class which in addition
to Open_table_state has a member for this savepoint. As result code
opening/closing system tables was changed to use Open_tables_backup
instead of Open_table_state class as well.
sql/sp.h:
Instead of using separate MDL_context for opening system tables we now
create MDL savepoint in the main context before opening such tables
and rollback to this savepoint after closing them. To support this
change methods of THD responsible for saving/restoring open table
state were changed to use Open_tables_backup class which in addition
to Open_table_state has a member for this savepoint. As result code
opening/closing system tables was changed to use Open_tables_backup
instead of Open_table_state class as well.
sql/sql_base.cc:
close_thread_tables():
Since we no longer use separate MDL_context for opening system
tables we need to avoid releasing all transaction locks when
closing system table. Releasing metadata lock on system table
is now responsibility of THD::restore_backup_open_tables_state().
open_table_get_mdl_lock(),
Open_table_context::recover_from_failed_open():
MDL subsystem no longer implicitly acquires global intention exclusive
metadata lock when per-object upgradable or exclusive metadata lock is
acquired. So this have to be done explicitly from these calls.
Changed Open_table_context class to store MDL_request object for
global intention exclusive lock acquired when opening tables.
open_table():
Do not release metadata lock if we have failed to open table as
this lock might have been acquired by one of previous statements
in transaction, and therefore should not be released.
open_system_tables_for_read()/close_system_tables()/
open_performance_schema_table():
Instead of using separate MDL_context for opening system tables we now
create MDL savepoint in the main context before opening such tables
and rollback to this savepoint after closing them. To support this
change methods of THD responsible for saving/restoring open table
state were changed to use Open_tables_backup class which in addition
to Open_table_state has a member for this savepoint. As result code
opening/closing system tables was changed to use Open_tables_backup
instead of Open_table_state class as well.
close_performance_schema_table():
Got rid of duplicated code.
sql/sql_class.cc:
Instead of using separate MDL_context for opening system tables we now
create MDL savepoint in the main context before opening such tables
and rollback to this savepoint after closing them. To support this
change methods of THD responsible for saving/restoring open table
state were changed to use Open_tables_backup class which in addition
to Open_table_state has a member for this savepoint. Also releasing
metadata lock on system table is now responsibility of
THD::restore_backup_open_tables_state().
Adjusted assert in THD::cleanup() to take into account fact that now
we also use MDL sentinel for global read lock.
sql/sql_class.h:
Instead of using separate MDL_context for opening system tables we now
create MDL savepoint in the main context before opening such tables
and rollback to this savepoint after closing them. As result:
- 'mdl_context' member was moved out of Open_tables_state to THD class.
enter_locked_tables_mode()/leave_locked_tables_mode() had to follow.
- Methods of THD responsible for saving/restoring open table state were
changed to use Open_tables_backup class which in addition to
Open_table_state has a member for this savepoint.
Changed Open_table_context class to store MDL_request object for
global intention exclusive lock acquired when opening tables.
sql/sql_delete.cc:
MDL subsystem no longer implicitly acquires global intention exclusive
metadata lock when per-object exclusive metadata lock is acquired.
Now this has to be done by explicit calls outside of MDL subsystem.
sql/sql_help.cc:
Instead of using separate MDL_context for opening system tables we now
create MDL savepoint in the main context before opening such tables
and rollback to this savepoint after closing them. To support this
change methods of THD responsible for saving/restoring open table
state were changed to use Open_tables_backup class which in addition
to Open_table_state has a member for this savepoint. As result code
opening/closing system tables was changed to use Open_tables_backup
instead of Open_table_state class as well.
sql/sql_parse.cc:
Adjusted assert reload_acl_and_cache() to the fact that global read
lock now takes full-blown metadata lock.
sql/sql_plist.h:
Added support for element counting to I_P_List list template.
One can use policy classes to specify if such counting is needed
or not needed for particular list.
sql/sql_show.cc:
Instead of using separate MDL_context for opening tables for I_S
purposes we now create MDL savepoint in the main context before
opening tables and rollback to this savepoint after closing them.
To support this and similar change for system tables methods of
THD responsible for saving/restoring open table state were changed
to use Open_tables_backup class which in addition to Open_table_state
has a member for this savepoint. As result code opening/closing tables
for I_S purposes was changed to use Open_tables_backup instead of
Open_table_state class as well.
sql/sql_table.cc:
mysql_rm_tables_part2():
Since now global intention exclusive metadata lock is ordinary
metadata lock we no longer can rely that by releasing MDL locks
on all tables we will release all locks acquired by this routine.
So in non-LOCK-TABLES mode we have to release all locks acquired
explicitly.
prepare_for_repair(), mysql_alter_table():
MDL subsystem no longer implicitly acquires global intention
exclusive metadata lock when per-object exclusive metadata lock
is acquired. Now this has to be done by explicit calls outside of
MDL subsystem.
sql/tztime.cc:
Instead of using separate MDL_context for opening system tables we now
create MDL savepoint in the main context before opening such tables
and rollback to this savepoint after closing them. To support this
change methods of THD responsible for saving/restoring open table
state were changed to use Open_tables_backup class which in addition
to Open_table_state has a member for this savepoint. As result code
opening/closing system tables was changed to use Open_tables_backup
instead of Open_table_state class as well.
Also changed code not to use special mechanism for open system tables
when it is not really necessary.
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.
Conflicts:
Text conflict in .bzr-mysql/default.conf
Text conflict in mysql-test/extra/rpl_tests/rpl_loaddata.test
Text conflict in mysql-test/r/mysqlbinlog2.result
Text conflict in mysql-test/suite/binlog/r/binlog_stm_mix_innodb_myisam.result
Text conflict in mysql-test/suite/binlog/r/binlog_unsafe.result
Text conflict in mysql-test/suite/rpl/r/rpl_insert_id.result
Text conflict in mysql-test/suite/rpl/r/rpl_loaddata.result
Text conflict in mysql-test/suite/rpl/r/rpl_stm_auto_increment_bug33029.result
Text conflict in mysql-test/suite/rpl/r/rpl_udf.result
Text conflict in mysql-test/suite/rpl/t/rpl_slow_query_log.test
Text conflict in sql/field.h
Text conflict in sql/log.cc
Text conflict in sql/log_event.cc
Text conflict in sql/log_event_old.cc
Text conflict in sql/mysql_priv.h
Text conflict in sql/share/errmsg.txt
Text conflict in sql/sp.cc
Text conflict in sql/sql_acl.cc
Text conflict in sql/sql_base.cc
Text conflict in sql/sql_class.h
Text conflict in sql/sql_db.cc
Text conflict in sql/sql_delete.cc
Text conflict in sql/sql_insert.cc
Text conflict in sql/sql_lex.cc
Text conflict in sql/sql_lex.h
Text conflict in sql/sql_load.cc
Text conflict in sql/sql_table.cc
Text conflict in sql/sql_update.cc
Text conflict in sql/sql_view.cc
Conflict adding files to storage/innobase. Created directory.
Conflict because storage/innobase is not versioned, but has versioned children. Versioned directory.
Conflict adding file storage/innobase. Moved existing file to storage/innobase.moved.
Conflict adding files to storage/innobase/handler. Created directory.
Conflict because storage/innobase/handler is not versioned, but has versioned children. Versioned directory.
Contents conflict in storage/innobase/handler/ha_innodb.cc
Conflicts:
Text conflict in .bzr-mysql/default.conf
Text conflict in mysql-test/extra/rpl_tests/rpl_loaddata.test
Text conflict in mysql-test/r/mysqlbinlog2.result
Text conflict in mysql-test/suite/binlog/r/binlog_stm_mix_innodb_myisam.result
Text conflict in mysql-test/suite/binlog/r/binlog_unsafe.result
Text conflict in mysql-test/suite/rpl/r/rpl_insert_id.result
Text conflict in mysql-test/suite/rpl/r/rpl_loaddata.result
Text conflict in mysql-test/suite/rpl/r/rpl_stm_auto_increment_bug33029.result
Text conflict in mysql-test/suite/rpl/r/rpl_udf.result
Text conflict in mysql-test/suite/rpl/t/rpl_slow_query_log.test
Text conflict in sql/field.h
Text conflict in sql/log.cc
Text conflict in sql/log_event.cc
Text conflict in sql/log_event_old.cc
Text conflict in sql/mysql_priv.h
Text conflict in sql/share/errmsg.txt
Text conflict in sql/sp.cc
Text conflict in sql/sql_acl.cc
Text conflict in sql/sql_base.cc
Text conflict in sql/sql_class.h
Text conflict in sql/sql_db.cc
Text conflict in sql/sql_delete.cc
Text conflict in sql/sql_insert.cc
Text conflict in sql/sql_lex.cc
Text conflict in sql/sql_lex.h
Text conflict in sql/sql_load.cc
Text conflict in sql/sql_table.cc
Text conflict in sql/sql_update.cc
Text conflict in sql/sql_view.cc
Conflict adding files to storage/innobase. Created directory.
Conflict because storage/innobase is not versioned, but has versioned children. Versioned directory.
Conflict adding file storage/innobase. Moved existing file to storage/innobase.moved.
Conflict adding files to storage/innobase/handler. Created directory.
Conflict because storage/innobase/handler is not versioned, but has versioned children. Versioned directory.
Contents conflict in storage/innobase/handler/ha_innodb.cc
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.
mysql-test/r/ps_ddl.result:
Update results (Bug#30977).
mysql-test/r/ps_ddl1.result:
Update results (Bug#30977).
mysql-test/r/sp-error.result:
Update results (Bug#30977).
mysql-test/r/sp-lock.result:
Update results (Bug#30977).
mysql-test/suite/rpl/r/rpl_sp.result:
Update results (Bug#30977).
mysql-test/suite/rpl/t/rpl_sp.test:
Add a test case for Bug#30977.
mysql-test/t/ps_ddl.test:
Update comments. We no longer re-prepare a prepared statement
when a stored procedure used in top-level CALL is changed.
mysql-test/t/ps_ddl1.test:
Modifying stored procedure p1 no longer invalidates prepared
statement "call p1" -- we can re-use the prepared statement
without invalidation.
mysql-test/t/sp-error.test:
Use a constant for an error value.
mysql-test/t/sp-lock.test:
Add test coverage for Bug#30977.
sql/lock.cc:
Implement lock_routine_name() - a way to acquire an
exclusive metadata lock (ex- name-lock) on
stored procedure/function.
sql/sp.cc:
Change semantics of sp_cache_routine() -- now it has an option
to make sure that the routine that is cached is up to date (has
the latest sp cache version).
Add sp_cache_invalidate() to sp_drop_routine(), where it was
missing (a bug!).
Acquire metadata locks for SP DDL (ALTER/CREATE/DROP). This is
the core of the fix for Bug#30977.
Since caching and cache invalidation scheme was changed, make
sure we don't invalidate the SP cache in the middle of a stored
routine execution. At the same time, make sure we don't access
stale data due to lack of invalidation.
For that, change ALTER FUNCTION/PROCEDURE to not use the cache,
and SHOW PROCEDURE CODE/SHOW CREATE PROCEDURE/FUNCTION to always
read an up to date version of the routine from the cache.
sql/sp.h:
Add a helper wrapper around sp_cache_routine().
sql/sp_cache.cc:
Implement new sp_cache_version() and sp_cache_flush_obsolete().
Now we flush stale routines individually, rather than all at once.
sql/sp_cache.h:
Update signatures of sp_cache_version() and sp_cache_flush_obsolete().
sql/sp_head.cc:
Add a default initialization of sp_head::m_sp_cache_version.
Remove a redundant sp_head::create().
sql/sp_head.h:
Add m_sp_cache_version to sp_head class - we now
keep track of every routine in the stored procedure cache, rather than
of the entire cache.
sql/sql_base.cc:
Implement prelocking for stored routines. Validate stored
routines after they were locked.
Flush obsolete routines upon next access, one by one, not all at once
(Bug#41804).
Style fixes.
sql/sql_class.h:
Rename a Open_table_context method.
sql/sql_parse.cc:
Make sure stored procedures DDL commits the active transaction
(issues an implicit commit before and after).
Remove sp_head::create(), a pure redundancy.
Move the semantical check during alter routine inside sp_update_routine() code in order to:
- avoid using SP cache during update, it may be obsolete.
- speed up and simplify the update procedure.
Remove sp_cache_flush_obsolete() calls, we no longer flush the entire
cache, ever, stale routines are flushed before next use, one at a time.
sql/sql_prepare.cc:
Move routine metadata validation to open_and_process_routine().
Fix Bug#49972 (don't swap flags at reprepare).
Reset Sroutine_hash_entries in reinit_stmt_before_use().
Remove SP cache invalidation, it's now done by open_tables().
sql/sql_show.cc:
Fix a warning: remove an unused label.
sql/sql_table.cc:
Reset mdl_request.ticket for tickets acquired for routines inlined
through a view, in CHECK TABLE statement, to satisfy an MDL assert.
sql/sql_update.cc:
Move the cleanup of "translation items" to close_tables_for_reopen(),
since it's needed in all cases when we back off, not just
the back-off in multi-update. This fixes a bug when the server
would crash on attempt to back off when opening tables
for a statement that uses information_schema tables.
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.
hide_view_error() does not take into account that thread query may be killed.
Added a check for thd->killed.
Addon: backported bug32140 fix from 6.0
mysql-test/r/sp_notembedded.result:
test case
mysql-test/t/sp_notembedded.test:
test case
sql/sp.cc:
backported bug32140 fix from 6.0
sql/table.cc:
Added a check for thd->killed.
------------------------------------------------------------
revno: 2617.68.25
committer: Dmitry Lenev <dlenev@mysql.com>
branch nick: mysql-next-bg-pre2-2
timestamp: Wed 2009-09-16 18:26:50 +0400
message:
Follow-up for one of pre-requisite patches for fixing bug #30977
"Concurrent statement using stored function and DROP FUNCTION
breaks SBR".
Made enum_mdl_namespace enum part of MDL_key class and removed MDL_
prefix from the names of enum members. In order to do the latter
changed name of PROCEDURE symbol to PROCEDURE_SYM (otherwise macro
which was automatically generated for this symbol conflicted with
MDL_key::PROCEDURE enum member).
------------------------------------------------------------
revno: 2617.68.25
committer: Dmitry Lenev <dlenev@mysql.com>
branch nick: mysql-next-bg-pre2-2
timestamp: Wed 2009-09-16 18:26:50 +0400
message:
Follow-up for one of pre-requisite patches for fixing bug #30977
"Concurrent statement using stored function and DROP FUNCTION
breaks SBR".
Made enum_mdl_namespace enum part of MDL_key class and removed MDL_
prefix from the names of enum members. In order to do the latter
changed name of PROCEDURE symbol to PROCEDURE_SYM (otherwise macro
which was automatically generated for this symbol conflicted with
MDL_key::PROCEDURE enum member).
------------------------------------------------------------
revno: 2617.68.24
committer: Dmitry Lenev <dlenev@mysql.com>
branch nick: mysql-next-bg-pre2-2
timestamp: Wed 2009-09-16 17:25:29 +0400
message:
Pre-requisite patch for fixing bug #30977 "Concurrent statement
using stored function and DROP FUNCTION breaks SBR".
Added MDL_request for stored routine as member to Sroutine_hash_entry
in order to be able perform metadata locking for stored routines in
future (Sroutine_hash_entry is an equivalent of TABLE_LIST class for
stored routines).
(WL#4284, follow up fixes).
sql/mdl.cc:
Introduced version of MDL_request::init() method which initializes
lock request using pre-built MDL key.
MDL_key::table_name/table_name_length() getters were
renamed to reflect the fact that MDL_key objects are
now created not only for tables.
sql/mdl.h:
Extended enum_mdl_namespace enum with values which correspond
to namespaces for stored functions and triggers.
Renamed MDL_key::table_name/table_name_length() getters
to MDL_key::name() and name_length() correspondingly to
reflect the fact that MDL_key objects are now created
not only for tables.
Added MDL_key::mdl_namespace() getter.
Also added version of MDL_request::init() method which
initializes lock request using pre-built MDL key.
sql/sp.cc:
Added MDL_request for stored routine as member to Sroutine_hash_entry.
Changed code to use MDL_key from this request as a key for LEX::sroutines
set. Removed separate "key" member from Sroutine_hash_entry as it became
unnecessary.
sql/sp.h:
Added MDL_request for stored routine as member to Sroutine_hash_entry
in order to be able perform metadata locking for stored routines in
future (Sroutine_hash_entry is an equivalent of TABLE_LIST class for
stored routines).
Removed Sroutine_hash_entry::key member as now we can use MDL_key from
this request as a key for LEX::sroutines set.
sql/sp_head.cc:
Removed sp_name::m_sroutines_key member and set_routine_type() method.
Since key for routine in LEX::sroutines set has no longer sp_name::m_qname
as suffix we won't save anything by creating it at sp_name construction
time.
Adjusted sp_name constructor used for creating temporary objects for
lookups in SP-cache to accept MDL_key as parameter and to avoid any
memory allocation.
Finally, removed sp_head::m_soutines_key member for reasons similar
to why sp_name::m_sroutines_key was removed
sql/sp_head.h:
Removed sp_name::m_sroutines_key member and set_routine_type() method.
Since key for routine in LEX::sroutines set has no longer sp_name::m_qname
as suffix we won't save anything by creating it at sp_name construction
time.
Adjusted sp_name constructor used for creating temporary objects for
lookups in SP-cache to accept MDL_key as parameter and to avoid any
memory allocation.
Finally, removed sp_head::m_soutines_key member for reasons similar
to why sp_name::m_sroutines_key was removed.
sql/sql_base.cc:
Adjusted code to the fact that we now use MDL_key from
Sroutine_hash_entry::mdl_request as a key for LEX::sroutines set.
MDL_key::table_name/table_name_length() getters were
renamed to reflect the fact that MDL_key objects are
now created not only for tables.
sql/sql_trigger.cc:
sp_add_used_routine() now takes MDL_key as parameter as now we use
instance of this class as a key for LEX::sroutines set.
------------------------------------------------------------
revno: 2617.68.24
committer: Dmitry Lenev <dlenev@mysql.com>
branch nick: mysql-next-bg-pre2-2
timestamp: Wed 2009-09-16 17:25:29 +0400
message:
Pre-requisite patch for fixing bug #30977 "Concurrent statement
using stored function and DROP FUNCTION breaks SBR".
Added MDL_request for stored routine as member to Sroutine_hash_entry
in order to be able perform metadata locking for stored routines in
future (Sroutine_hash_entry is an equivalent of TABLE_LIST class for
stored routines).
(WL#4284, follow up 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).
sql/sql_base.cc:
Implement different prelocking strategies. Use an instance of
prelocking_strategy in open_tables().
sql/sql_class.h:
Add declarations for class Prelocking_strategy.
sql/sql_lex.h:
Add a helper method to access last table of the global table list
(lex->query_tables).
sql/sql_parse.cc:
Use a special prelocking strategy when locking tables for LOCK TABLES.
sql/sql_table.cc:
Use normal open_and_lock_tables_derived() in ALTER TABLE.
sql/sql_yacc.yy:
Modify the grammar to not pollute the global table list with tables
that should not be opened.
----------------------------------------------------------
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.
sql/event_db_repository.cc:
Remove alloc_mdl_requests(). Now MDL_request instance is a member
of TABLE_LIST, and init_one_table() initializes it.
sql/ha_ndbcluster_binlog.cc:
Remove now unnecessary declaration and initialization
of binlog_mdl_request.
sql/lock.cc:
No need to allocate MDL requests in lock_table_names() now.
sql/log.cc:
Use init_one_table() method, remove alloc_mdl_requests(),
which is now unnecessary.
sql/log_event.cc:
No need to allocate mdl_request separately now.
Use init_one_table() method.
sql/log_event_old.cc:
Update to the new signature of close_tables_for_reopen().
sql/mdl.cc:
Update try_acquire_exclusive_lock() to be more easy to use.
Function lock_table_name_if_not_cached() has been removed.
Make acquire_shared_lock() signature consistent with
try_acquire_exclusive_lock() signature.
Remove methods that are no longer used.
Update comments.
sql/mdl.h:
Implement an assignment operator that doesn't
copy MDL_key (MDL_key::operator= is private and
should remain private).
This is a hack to work-around assignment of TABLE_LIST
by value in several places. Such assignments violate
encapsulation, since only perform a shallow copy.
In most cases these assignments are a hack on their own.
sql/mysql_priv.h:
Update signatures of close_thread_tables() and close_tables_for_reopen().
sql/sp.cc:
Allocate TABLE_LIST in thd->mem_root.
Use init_one_table().
sql/sp_head.cc:
Use init_one_table().
Remove thd->locked_tables_root, it's no longer needed.
sql/sql_acl.cc:
Use init_mdl_requests() and init_one_table().
sql/sql_base.cc:
Update to new signatures of try_acquire_shared_lock() and
try_acquire_exclusive_lock().
Remove lock_table_name_if_not_cached().
Fix a bug in open_ltable() that would not return ER_LOCK_DEADLOCK
in case of a failed lock_tables() and a multi-statement
transaction.
Fix a bug in open_and_lock_tables_derived() that would
not return ER_LOCK_DEADLOCK in case of a multi-statement
transaction and a failure of lock_tables().
Move assignment of enum_open_table_action to a method of Open_table_context, a new class that maintains information
for backoff actions.
Minor rearrangements of the code.
Remove alloc_mdl_requests() in functions that work with system
tables: instead the patch ensures that callers always initialize
TABLE_LIST argument.
sql/sql_class.cc:
THD::locked_tables_root is no more.
sql/sql_class.h:
THD::locked_tables_root is no more.
Add a declaration for Open_table_context class.
sql/sql_delete.cc:
Update to use the simplified MDL API.
sql/sql_handler.cc:
TABLE_LIST::mdl_request is stored by-value now.
Ensure that mdl_request.ticket is NULL for every request
that is passed into MDL, to satisfy MDL asserts.
@ sql/sql_help.cc
Function open_system_tables_for_read() no longer initializes
mdl_requests.
Move TABLE_LIST::mdl_request initialization closer to
TABLE_LIST initialization.
sql/sql_help.cc:
Function open_system_tables_for_read() no longer initializes
mdl_requests.
Move TABLE_LIST::mdl_request initialization closer to
TABLE_LIST initialization.
sql/sql_insert.cc:
Remove assignment by-value of TABLE_LIST in
TABLEOP_HOOKS. We can't carry over a granted
MDL ticket from one table list to another.
sql/sql_parse.cc:
Change alloc_mdl_requests() -> init_mdl_requests().
@todo We can remove init_mdl_requests() altogether
in some places: all places that call add_table_to_list()
already have mdl requests initialized.
sql/sql_plugin.cc:
Use init_one_table().
THD::locked_tables_root is no more.
sql/sql_servers.cc:
Use init_one_table().
sql/sql_show.cc:
Update acquire_high_priority_shared_lock() to use
TABLE_LIST::mdl_request rather than allocate an own.
Fix get_trigger_table_impl() to use init_one_table(),
check for out of memory, follow the coding style.
sql/sql_table.cc:
Update to work with TABLE_LIST::mdl_request by-value.
Remove lock_table_name_if_not_cached().
The code that used to delegate to it is quite simple and
concise without it now.
sql/sql_udf.cc:
Use init_one_table().
sql/sql_update.cc:
Update to use the new signature of close_tables_for_reopen().
sql/table.cc:
Move re-setting of mdl_requests for prepared statements
and stored procedures from close_thread_tables() to
reinit_stmt_before_use().
Change alloc_mdl_requests() to init_mdl_requests().
init_mdl_requests() is a hack that can't be deleted
until we don't have a list-aware TABLE_LIST constructor.
Hopefully its use will be minimal
sql/table.h:
Change alloc_mdl_requests() to init_mdl_requests()
TABLE_LIST::mdl_request is stored by value.
sql/tztime.cc:
We no longer initialize mdl requests in open_system_tables_for*()
functions. Move this initialization closer to initialization
of the rest of TABLE_LIST members.
storage/myisammrg/ha_myisammrg.cc:
Simplify mdl_request initialization.
----------------------------------------------------------
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: 2630.2.7
committer: Konstantin Osipov <konstantin@mysql.com>
branch nick: mysql-6.0-runtime
timestamp: Wed 2008-06-04 15:18:52 +0400
message:
Fix a code regression (not observable externally) that I introduced
in the fix for Bug#26141
(backporting as part of all patches related to WL#3726)
----------------------------------------------------------
revno: 2630.2.7
committer: Konstantin Osipov <konstantin@mysql.com>
branch nick: mysql-6.0-runtime
timestamp: Wed 2008-06-04 15:18:52 +0400
message:
Fix a code regression (not observable externally) that I introduced
in the fix for Bug#26141
(backporting as part of all patches related to WL#3726)
Problem: SHOW CREATE FUNCTION and SELECT DTD_IDENTIFIER FROM I_S.ROUTINES
returned wrong values in case of ENUM return data type and UCS2
character set.
Fix: the string to collect returned data type was incorrectly set to
"binary" character set, therefore UCS2 values where returned with
extra '\0' characters.
Setting string character set to creation_ctx->get_client_cs()
in sp_find_routine(), and to system_charset_info in sp_create_routine
fixes the problem.
Adding tests:
- the original test with Latin letters
- an extra test with non-Latin letters
Problem: SHOW CREATE FUNCTION and SELECT DTD_IDENTIFIER FROM I_S.ROUTINES
returned wrong values in case of ENUM return data type and UCS2
character set.
Fix: the string to collect returned data type was incorrectly set to
"binary" character set, therefore UCS2 values where returned with
extra '\0' characters.
Setting string character set to creation_ctx->get_client_cs()
in sp_find_routine(), and to system_charset_info in sp_create_routine
fixes the problem.
Adding tests:
- the original test with Latin letters
- an extra test with non-Latin letters
The problem is that the server could crash when attempting
to access a non-conformant proc system table. One such case
was a crash when invoking stored procedure related statements
on a 5.1 server with a proc system table in the 5.0 format.
The solution is to validate the proc system table format
before attempts to access it are made. If the table is not
in the format that the server expects, a message is written
to the error log and the statement that caused the table to
be accessed fails.
mysql-test/r/sp-destruct.result:
Add test case result for Bug#41726
mysql-test/t/sp-destruct.test:
Add test case for Bug#41726
sql/event_db_repository.cc:
Update code to use new structures.
sql/sp.cc:
Describe the proc table format and use it to validate when
opening a instance of the table.
Add a check to insure that a error message is written to
the error log only once.
sql/sql_acl.cc:
Remove unused variable and use new structure.
sql/sql_acl.h:
Export field definition.
sql/table.cc:
Accept the field count and definition in a single structure.
sql/table.h:
Combine the field count and definition in a single structure.
Transform function into a class in order to support different
ways of reporting a error.
Add a pointer cache to TABLE_SHARE.
The problem is that the server could crash when attempting
to access a non-conformant proc system table. One such case
was a crash when invoking stored procedure related statements
on a 5.1 server with a proc system table in the 5.0 format.
The solution is to validate the proc system table format
before attempts to access it are made. If the table is not
in the format that the server expects, a message is written
to the error log and the statement that caused the table to
be accessed fails.
