bug #57006 "Deadlock between HANDLER and FLUSH TABLES WITH READ
LOCK" and bug #54673 "It takes too long to get readlock for
'FLUSH TABLES WITH READ LOCK'".
The first bug manifested itself as a deadlock which occurred
when a connection, which had some table open through HANDLER
statement, tried to update some data through DML statement
while another connection tried to execute FLUSH TABLES WITH
READ LOCK concurrently.
What happened was that FTWRL in the second connection managed
to perform first step of GRL acquisition and thus blocked all
upcoming DML. After that it started to wait for table open
through HANDLER statement to be flushed. When the first connection
tried to execute DML it has started to wait for GRL/the second
connection creating deadlock.
The second bug manifested itself as starvation of FLUSH TABLES
WITH READ LOCK statements in cases when there was a constant
stream of concurrent DML statements (in two or more
connections).
This has happened because requests for protection against GRL
which were acquired by DML statements were ignoring presence of
pending GRL and thus the latter was starved.
This patch solves both these problems by re-implementing GRL
using metadata locks.
Similar to the old implementation acquisition of GRL in new
implementation is two-step. During the first step we block
all concurrent DML and DDL statements by acquiring global S
metadata lock (each DML and DDL statement acquires global IX
lock for its duration). During the second step we block commits
by acquiring global S lock in COMMIT namespace (commit code
acquires global IX lock in this namespace).
Note that unlike in old implementation acquisition of
protection against GRL in DML and DDL is semi-automatic.
We assume that any statement which should be blocked by GRL
will either open and acquires write-lock on tables or acquires
metadata locks on objects it is going to modify. For any such
statement global IX metadata lock is automatically acquired
for its duration.
The first problem is solved because waits for GRL become
visible to deadlock detector in metadata locking subsystem
and thus deadlocks like one in the first bug become impossible.
The second problem is solved because global S locks which
are used for GRL implementation are given preference over
IX locks which are acquired by concurrent DML (and we can
switch to fair scheduling in future if needed).
Important change:
FTWRL/GRL no longer blocks DML and DDL on temporary tables.
Before this patch behavior was not consistent in this respect:
in some cases DML/DDL statements on temporary tables were
blocked while in others they were not. Since the main use cases
for FTWRL are various forms of backups and temporary tables are
not preserved during backups we have opted for consistently
allowing DML/DDL on temporary tables during FTWRL/GRL.
Important change:
This patch changes thread state names which are used when
DML/DDL of FTWRL is waiting for global read lock. It is now
either "Waiting for global read lock" or "Waiting for commit
lock" depending on the stage on which FTWRL is.
Incompatible change:
To solve deadlock in events code which was exposed by this
patch we have to replace LOCK_event_metadata mutex with
metadata locks on events. As result we have to prohibit
DDL on events under LOCK TABLES.
This patch also adds extensive test coverage for interaction
of DML/DDL and FTWRL.
Performance of new and old global read lock implementations
in sysbench tests were compared. There were no significant
difference between new and old implementations.
mysql-test/include/check_ftwrl_compatible.inc:
Added helper script which allows to check that a statement is
compatible with FLUSH TABLES WITH READ LOCK.
mysql-test/include/check_ftwrl_incompatible.inc:
Added helper script which allows to check that a statement is
incompatible with FLUSH TABLES WITH READ LOCK.
mysql-test/include/handler.inc:
Adjusted test case to the fact that now DROP TABLE closes
open HANDLERs for the table to be dropped before checking
if there active FTWRL in this connection.
mysql-test/include/wait_show_condition.inc:
Fixed small error in the timeout message. The correct name
of variable used as parameter for this script is "$condition"
and not "$wait_condition".
mysql-test/r/delayed.result:
Added test coverage for scenario which triggered assert in
metadata locking subsystem.
mysql-test/r/events_2.result:
Updated test results after prohibiting event DDL operations
under LOCK TABLES.
mysql-test/r/flush.result:
Added test coverage for bug #57006 "Deadlock between HANDLER
and FLUSH TABLES WITH READ LOCK".
mysql-test/r/flush_read_lock.result:
Added test coverage for various aspects of FLUSH TABLES WITH
READ LOCK functionality.
mysql-test/r/flush_read_lock_kill.result:
Adjusted test case after replacing custom global read lock
implementation with one based on metadata locks. Use new
debug_sync point. Do not disable concurrent inserts as now
InnoDB we always use InnoDB table.
mysql-test/r/handler_innodb.result:
Adjusted test case to the fact that now DROP TABLE closes
open HANDLERs for the table to be dropped before checking
if there active FTWRL in this connection.
mysql-test/r/handler_myisam.result:
Adjusted test case to the fact that now DROP TABLE closes
open HANDLERs for the table to be dropped before checking
if there active FTWRL in this connection.
mysql-test/r/mdl_sync.result:
Adjusted test case after replacing custom global read lock
implementation with one based on metadata locks. Replaced
usage of GRL-specific debug_sync's with appropriate sync
points in MDL subsystem.
mysql-test/suite/perfschema/r/dml_setup_instruments.result:
Updated test results after removing global
COND_global_read_lock condition variable.
mysql-test/suite/perfschema/r/func_file_io.result:
Ensure that this test doesn't affect subsequent tests.
At the end of its execution enable back P_S instrumentation
which this test disables at some point.
mysql-test/suite/perfschema/r/func_mutex.result:
Ensure that this test doesn't affect subsequent tests.
At the end of its execution enable back P_S instrumentation
which this test disables at some point.
mysql-test/suite/perfschema/r/global_read_lock.result:
Adjusted test case to take into account that new GRL
implementation is based on MDL.
mysql-test/suite/perfschema/r/server_init.result:
Adjusted test case after replacing custom global read
lock implementation with one based on MDL and replacing
LOCK_event_metadata mutex with metadata lock.
mysql-test/suite/perfschema/t/func_file_io.test:
Ensure that this test doesn't affect subsequent tests.
At the end of its execution enable back P_S instrumentation
which this test disables at some point.
mysql-test/suite/perfschema/t/func_mutex.test:
Ensure that this test doesn't affect subsequent tests.
At the end of its execution enable back P_S instrumentation
which this test disables at some point.
mysql-test/suite/perfschema/t/global_read_lock.test:
Adjusted test case to take into account that new GRL
implementation is based on MDL.
mysql-test/suite/perfschema/t/server_init.test:
Adjusted test case after replacing custom global read
lock implementation with one based on MDL and replacing
LOCK_event_metadata mutex with metadata lock.
mysql-test/suite/rpl/r/rpl_tmp_table_and_DDL.result:
Updated test results after prohibiting event DDL under
LOCK TABLES.
mysql-test/t/delayed.test:
Added test coverage for scenario which triggered assert in
metadata locking subsystem.
mysql-test/t/events_2.test:
Updated test case after prohibiting event DDL operations
under LOCK TABLES.
mysql-test/t/flush.test:
Added test coverage for bug #57006 "Deadlock between HANDLER
and FLUSH TABLES WITH READ LOCK".
mysql-test/t/flush_block_commit.test:
Adjusted test case after changing thread state name which
is used when COMMIT waits for FLUSH TABLES WITH READ LOCK
from "Waiting for release of readlock" to "Waiting for commit
lock".
mysql-test/t/flush_block_commit_notembedded.test:
Adjusted test case after changing thread state name which is
used when DML waits for FLUSH TABLES WITH READ LOCK. Now we
use "Waiting for global read lock" in this case.
mysql-test/t/flush_read_lock.test:
Added test coverage for various aspects of FLUSH TABLES WITH
READ LOCK functionality.
mysql-test/t/flush_read_lock_kill-master.opt:
We no longer need to use make_global_read_lock_block_commit_loop
debug tag in this test. Instead we rely on an appropriate
debug_sync point in MDL code.
mysql-test/t/flush_read_lock_kill.test:
Adjusted test case after replacing custom global read lock
implementation with one based on metadata locks. Use new
debug_sync point. Do not disable concurrent inserts as now
InnoDB we always use InnoDB table.
mysql-test/t/lock_multi.test:
Adjusted test case after changing thread state names which
are used when DML or DDL waits for FLUSH TABLES WITH READ
LOCK to "Waiting for global read lock".
mysql-test/t/mdl_sync.test:
Adjusted test case after replacing custom global read lock
implementation with one based on metadata locks. Replaced
usage of GRL-specific debug_sync's with appropriate sync
points in MDL subsystem. Updated thread state names which
are used when DDL waits for FTWRL.
mysql-test/t/trigger_notembedded.test:
Adjusted test case after changing thread state names which
are used when DML or DDL waits for FLUSH TABLES WITH READ
LOCK to "Waiting for global read lock".
sql/event_data_objects.cc:
Removed Event_queue_element::status/last_executed_changed
members and Event_queue_element::update_timing_fields()
method. We no longer use this class for updating mysql.events
once event is chosen for execution. Accesses to instances of
this class in scheduler thread require protection by
Event_queue::LOCK_event_queue mutex and we try to avoid
updating table while holding this lock.
sql/event_data_objects.h:
Removed Event_queue_element::status/last_executed_changed
members and Event_queue_element::update_timing_fields()
method. We no longer use this class for updating mysql.events
once event is chosen for execution. Accesses to instances of
this class in scheduler thread require protection by
Event_queue::LOCK_event_queue mutex and we try to avoid
updating table while holding this lock.
sql/event_db_repository.cc:
- Changed Event_db_repository methods to not release all
metadata locks once they are done updating mysql.events
table. This allows to keep metadata lock protecting
against GRL and lock protecting particular event around
until corresponding DDL statement is written to the binary
log.
- Removed logic for conditional update of "status" and
"last_executed" fields from update_timing_fields_for_event()
method. In the only case when this method is called now
"last_executed" is always modified and tracking change
of "status" is too much hassle.
sql/event_db_repository.h:
Removed logic for conditional update of "status" and
"last_executed" fields from Event_db_repository::
update_timing_fields_for_event() method.
In the only case when this method is called now "last_executed"
is always modified and tracking change of "status" field is
too much hassle.
sql/event_queue.cc:
Changed event scheduler code not to update mysql.events
table while holding Event_queue::LOCK_event_queue mutex.
Doing so led to a deadlock with a new GRL implementation.
This deadlock didn't occur with old implementation due to
fact that code acquiring protection against GRL ignored
pending GRL requests (which lead to GRL starvation).
One of goals of new implementation is to disallow GRL
starvation and so we have to solve problem with this
deadlock in a different way.
sql/events.cc:
Changed methods of Events class to acquire protection
against GRL while perfoming DDL statement and keep it
until statement is written to the binary log.
Unfortunately this step together with new GRL implementation
exposed deadlock involving Events::LOCK_event_metadata
and GRL. To solve it Events::LOCK_event_metadata mutex was
replaced with a metadata lock on event. As a side-effect
events DDL has to be prohibited under LOCK TABLES even in
cases when mysql.events table was explicitly locked for
write.
sql/events.h:
Replaced Events::LOCK_event_metadata mutex with a metadata
lock on event.
sql/ha_ndbcluster.cc:
Updated code after replacing custom global read lock
implementation with one based on MDL. Since MDL subsystem
should now be able to detect deadlocks involving metadata
locks and GRL there is no need for special handling of
active GRL.
sql/handler.cc:
Replaced custom implementation of global read lock with
one based on metadata locks. Consequently when doing
commit instead of calling method of Global_read_lock
class to acquire protection against GRL we simply acquire
IX in COMMIT namespace.
sql/lock.cc:
Replaced custom implementation of global read lock with
one based on metadata locks. This step allows to expose
wait for GRL to deadlock detector of MDL subsystem and
thus succesfully resolve deadlocks similar to one behind
bug #57006 "Deadlock between HANDLER and FLUSH TABLES
WITH READ LOCK". It also solves problem with GRL starvation
described in bug #54673 "It takes too long to get readlock
for 'FLUSH TABLES WITH READ LOCK'" since metadata locks used
by GRL give preference to FTWRL statement instead of DML
statements (if needed in future this can be changed to
fair scheduling).
Similar to old implementation of acquisition of GRL is
two-step. During the first step we block all concurrent
DML and DDL statements by acquiring global S metadata lock
(each DML and DDL statement acquires global IX lock for
its duration). During the second step we block commits by
acquiring global S lock in COMMIT namespace (commit code
acquires global IX lock in this namespace).
Note that unlike in old implementation acquisition of
protection against GRL in DML and DDL is semi-automatic.
We assume that any statement which should be blocked by GRL
will either open and acquires write-lock on tables or acquires
metadata locks on objects it is going to modify. For any such
statement global IX metadata lock is automatically acquired
for its duration.
To support this change:
- Global_read_lock::lock/unlock_global_read_lock and
make_global_read_lock_block_commit methods were changed
accordingly.
- Global_read_lock::wait_if_global_read_lock() and
start_waiting_global_read_lock() methods were dropped.
It is now responsibility of code acquiring metadata locks
opening tables to acquire protection against GRL by
explicitly taking global IX lock with statement duration.
- Global variables, mutex and condition variable used by
old implementation was removed.
- lock_routine_name() was changed to use statement duration for
its global IX lock. It was also renamed to lock_object_name()
as it now also used to take metadata locks on events.
- Global_read_lock::set_explicit_lock_duration() was added which
allows not to release locks used for GRL when leaving prelocked
mode.
sql/lock.h:
- Renamed lock_routine_name() to lock_object_name() and changed
its signature to allow its usage for events.
- Removed broadcast_refresh() function. It is no longer needed
with new GRL implementation.
sql/log_event.cc:
Release metadata locks with statement duration at the end
of processing legacy event for LOAD DATA. This ensures that
replication thread processing such event properly releases
its protection against global read lock.
sql/mdl.cc:
Changed MDL subsystem to support new MDL-based implementation
of global read lock.
Added COMMIT and EVENTS namespaces for metadata locks. Changed
thread state name for GLOBAL namespace to "Waiting for global
read lock".
Optimized MDL_map::find_or_insert() method to avoid taking
m_mutex mutex when looking up MDL_lock objects for GLOBAL
or COMMIT namespaces. We keep pre-created MDL_lock objects
for these namespaces around and simply return pointers to
these global objects when needed.
Changed MDL_lock/MDL_scoped_lock to properly handle
notification of insert delayed handler threads when FTWRL
takes global S lock.
Introduced concept of lock duration. In addition to locks with
transaction duration which work in the way which is similar to
how locks worked before (i.e. they are released at the end of
transaction), locks with statement and explicit duration were
introduced.
Locks with statement duration are automatically released at the
end of statement. Locks with explicit duration require explicit
release and obsolete concept of transactional sentinel.
* Changed MDL_request and MDL_ticket classes to support notion
of duration.
* Changed MDL_context to keep locks with different duration in
different lists. Changed code handling ticket list to take
this into account.
* Changed methods responsible for releasing locks to take into
account duration of tickets. Particularly public
MDL_context::release_lock() method now only can release
tickets with explicit duration (there is still internal
method which allows to specify duration). To release locks
with statement or transaction duration one have to use
release_statement/transactional_locks() methods.
* Concept of savepoint for MDL subsystem now has to take into
account locks with statement duration. Consequently
MDL_savepoint class was introduced and methods working with
savepoints were updated accordingly.
* Added methods which allow to set duration for one or all
locks in the context.
sql/mdl.h:
Changed MDL subsystem to support new MDL-based implementation
of global read lock.
Added COMMIT and EVENTS namespaces for metadata locks.
Introduced concept of lock duration. In addition to locks with
transaction duration which work in the way which is similar to
how locks worked before (i.e. they are released at the end of
transaction), locks with statement and explicit duration were
introduced.
Locks with statement duration are automatically released at the
end of statement. Locks with explicit duration require explicit
release and obsolete concept of transactional sentinel.
* Changed MDL_request and MDL_ticket classes to support notion
of duration.
* Changed MDL_context to keep locks with different duration in
different lists. Changed code handling ticket list to take
this into account.
* Changed methods responsible for releasing locks to take into
account duration of tickets. Particularly public
MDL_context::release_lock() method now only can release
tickets with explicit duration (there is still internal
method which allows to specify duration). To release locks
with statement or transaction duration one have to use
release_statement/transactional_locks() methods.
* Concept of savepoint for MDL subsystem now has to take into
account locks with statement duration. Consequently
MDL_savepoint class was introduced and methods working with
savepoints were updated accordingly.
* Added methods which allow to set duration for one or all
locks in the context.
sql/mysqld.cc:
Removed global mutex and condition variables which were used
by old implementation of GRL.
Also we no longer need to initialize Events::LOCK_event_metadata
mutex as it was replaced with metadata locks on events.
sql/mysqld.h:
Removed global variable, mutex and condition variables which
were used by old implementation of GRL.
sql/rpl_rli.cc:
When slave thread closes tables which were open for handling
of RBR events ensure that it releases global IX lock which
was acquired as protection against GRL.
sql/sp.cc:
Adjusted code to the new signature of lock_object/routine_name(),
to the fact that one now needs specify duration of lock when
initializing MDL_request and to the fact that savepoints for MDL
subsystem are now represented by MDL_savepoint class.
sql/sp_head.cc:
Ensure that statements in stored procedures release statement
metadata locks and thus release their protectiong against GRL
in proper moment in time.
Adjusted code to the fact that one now needs specify duration
of lock when initializing MDL_request.
sql/sql_admin.cc:
Adjusted code to the fact that one now needs specify duration
of lock when initializing MDL_request.
sql/sql_base.cc:
- Implemented support for new approach to acquiring protection
against global read lock. We no longer acquire such protection
explicitly on the basis of statement flags. Instead we always
rely on code which is responsible for acquiring metadata locks
on object to be changed acquiring this protection. This is
achieved by acquiring global IX metadata lock with statement
duration. Code doing this also responsible for checking that
current connection has no active GRL by calling an
Global_read_lock::can_acquire_protection() method.
Changed code in open_table() and lock_table_names()
accordingly.
Note that as result of this change DDL and DML on temporary
tables is always compatible with GRL (before it was
incompatible in some cases and compatible in other cases).
- To speed-up code acquiring protection against GRL introduced
m_has_protection_against_grl member in Open_table_context
class. It indicates that protection was already acquired
sometime during open_tables() execution and new attempts
can be skipped.
- Thanks to new GRL implementation calls to broadcast_refresh()
became unnecessary and were removed.
- Adjusted code to the fact that one now needs specify duration
of lock when initializing MDL_request and to the fact that
savepoints for MDL subsystem are now represented by
MDL_savepoint class.
sql/sql_base.h:
Adjusted code to the fact that savepoints for MDL subsystem are
now represented by MDL_savepoint class.
Also introduced Open_table_context::m_has_protection_against_grl
member which allows to avoid acquiring protection against GRL
while opening tables if such protection was already acquired.
sql/sql_class.cc:
Changed THD::leave_locked_tables_mode() after transactional
sentinel for metadata locks was obsoleted by introduction of
locks with explicit duration.
sql/sql_class.h:
- Adjusted code to the fact that savepoints for MDL subsystem
are now represented by MDL_savepoint class.
- Changed Global_read_lock class according to changes in
global read lock implementation:
* wait_if_global_read_lock and start_waiting_global_read_lock
are now gone. Instead code needing protection against GRL
has to acquire global IX metadata lock with statement
duration itself. To help it new can_acquire_protection()
was introduced. Also as result of the above change
m_protection_count member is gone too.
* Added m_mdl_blocks_commits_lock member to store metadata
lock blocking commits.
* Adjusted code to the fact that concept of transactional
sentinel was obsoleted by concept of lock duration.
- Removed CF_PROTECT_AGAINST_GRL flag as it is no longer
necessary. New GRL implementation acquires protection
against global read lock automagically when statement
acquires metadata locks on tables or other objects it
is going to change.
sql/sql_db.cc:
Adjusted code to the fact that one now needs specify duration
of lock when initializing MDL_request.
sql/sql_handler.cc:
Removed call to broadcast_refresh() function. It is no longer
needed with new GRL implementation.
Adjusted code after introducing duration concept for metadata
locks. Particularly to the fact transactional sentinel was
replaced with explicit duration.
sql/sql_handler.h:
Renamed mysql_ha_move_tickets_after_trans_sentinel() to
mysql_ha_set_explicit_lock_duration() after transactional
sentinel was obsoleted by locks with explicit duration.
sql/sql_insert.cc:
Adjusted code handling delaying inserts after switching to
new GRL implementation. Now connection thread initiating
delayed insert has to acquire global IX lock in addition
to metadata lock on table being inserted into. This IX lock
protects against GRL and similarly to SW lock on table being
inserted into has to be passed to handler thread in order to
avoid deadlocks.
sql/sql_lex.cc:
LEX::protect_against_global_read_lock member is no longer
necessary since protection against GRL is automatically
taken by code acquiring metadata locks/opening tables.
sql/sql_lex.h:
LEX::protect_against_global_read_lock member is no longer
necessary since protection against GRL is automatically
taken by code acquiring metadata locks/opening tables.
sql/sql_parse.cc:
- Implemented support for new approach to acquiring protection
against global read lock. We no longer acquire such protection
explicitly on the basis of statement flags. Instead we always
rely on code which is responsible for acquiring metadata locks
on object to be changed acquiring this protection. This is
achieved by acquiring global IX metadata lock with statement
duration. This lock is automatically released at the end of
statement execution.
- Changed implementation of CREATE/DROP PROCEDURE/FUNCTION not
to release metadata locks and thus protection against of GRL
in the middle of statement execution.
- Adjusted code to the fact that one now needs specify duration
of lock when initializing MDL_request and to the fact that
savepoints for MDL subsystem are now represented by
MDL_savepoint class.
sql/sql_prepare.cc:
Adjusted code to the to the fact that savepoints for MDL
subsystem are now represented by MDL_savepoint class.
sql/sql_rename.cc:
With new GRL implementation there is no need to explicitly
acquire protection against GRL before renaming tables.
This happens automatically in code which acquires metadata
locks on tables being renamed.
sql/sql_show.cc:
Adjusted code to the fact that one now needs specify duration
of lock when initializing MDL_request and to the fact that
savepoints for MDL subsystem are now represented by
MDL_savepoint class.
sql/sql_table.cc:
- With new GRL implementation there is no need to explicitly
acquire protection against GRL before dropping tables.
This happens automatically in code which acquires metadata
locks on tables being dropped.
- Changed mysql_alter_table() not to release lock on new table
name explicitly and to rely on automatic release of locks
at the end of statement instead. This was necessary since
now MDL_context::release_lock() is supported only for locks
for explicit duration.
sql/sql_trigger.cc:
With new GRL implementation there is no need to explicitly
acquire protection against GRL before changing table triggers.
This happens automatically in code which acquires metadata
locks on tables which triggers are to be changed.
sql/sql_update.cc:
Fix bug exposed by GRL testing. During prepare phase acquire
only S metadata locks instead of SW locks to keep prepare of
multi-UPDATE compatible with concurrent LOCK TABLES WRITE
and global read lock.
sql/sql_view.cc:
With new GRL implementation there is no need to explicitly
acquire protection against GRL before creating view.
This happens automatically in code which acquires metadata
lock on view to be created.
sql/sql_yacc.yy:
LEX::protect_against_global_read_lock member is no longer
necessary since protection against GRL is automatically
taken by code acquiring metadata locks/opening tables.
sql/table.cc:
Adjusted code to the fact that one now needs specify duration
of lock when initializing MDL_request.
sql/table.h:
Adjusted code to the fact that one now needs specify duration
of lock when initializing MDL_request.
sql/transaction.cc:
Replaced custom implementation of global read lock with
one based on metadata locks. Consequently when doing
commit instead of calling method of Global_read_lock
class to acquire protection against GRL we simply acquire
IX in COMMIT namespace.
Also adjusted code to the fact that MDL savepoint is now
represented by MDL_savepoint class.
"Grantor" columns' data is lost when replicating mysql.tables_priv.
Slave SQL thread used its default user ''@'' as the grantor of GRANT|REVOKE
statements executing on it.
In this patch, current user is put in query log event for all GRANT and REVOKE
statement, SQL thread uses the user in query log event as grantor.
mysql-test/suite/rpl/r/rpl_do_grant.result:
Add test for this bug.
mysql-test/suite/rpl/t/rpl_do_grant.test:
Add test for this bug.
sql/log_event.cc:
Refactoring THD::current_user_used and related functions.
current_user_used is used to judge if current user should be
binlogged in query log event. So it is better to call it m_binlog_invoker.
The related functions are renamed too.
sql/sql_class.cc:
Refactoring THD::current_user_used and related functions.
current_user_used is used to judge if current user should be
binlogged in query log event. So it is better to call it m_binlog_invoker.
The related functions are renamed too.
sql/sql_class.h:
Refactoring THD::current_user_used and related functions.
current_user_used is used to judge if current user should be
binlogged in query log event. So it is better to call it m_binlog_invoker.
The related functions are renamed too.
sql/sql_parse.cc:
Call binlog_invoker() for GRANT and REVOKE statements.
- A prerequisite cleanup patch for making KILL reliable.
The test case main.kill did not work reliably.
The following problems have been identified:
1. A kill signal could go lost if it came in, short before a
thread went reading on the client connection.
2. A kill signal could go lost if it came in, short before a
thread went waiting on a condition variable.
These problems have been solved as follows. Please see also
added code comments for more details.
1. There is no safe way to detect, when a thread enters the
blocking state of a read(2) or recv(2) system call, where it
can be interrupted by a signal. Hence it is not possible to
wait for the right moment to send a kill signal. It has been
decided, not to fix it in the code. Instead, the test case
repeats the KILL statement until the connection terminates.
2. Before waiting on a condition variable, we register it
together with a synchronizating mutex in THD::mysys_var. After
this, we need to test THD::killed again. At some places we did
only test it in a loop condition before the registration. When
THD::killed had been set between this test and the registration,
we entered waiting without noticing the killed flag. Additional
checks ahve been introduced where required.
In addition to the above, a re-write of the main.kill test
case has been done. All sleeps have been replaced by Debug
Sync Facility synchronization. A couple of sync points have
been added to the server code.
To avoid further problems, if the test case fails in spite of
the fixes, the test case has been added to the "experimental"
list for now.
- Most of the work on this patch is authored by Ingo Struewing
mysql-test/t/kill.test:
Re-wrote test case to use Debug Sync points instead of sleeps
sql/event_queue.cc:
Fixed kill detection in Event_queue::cond_wait() by adding a check
after enter_cond().
sql/lock.cc:
Moved Debug Sync points behind enter_cond().
Fixed comments.
sql/slave.cc:
Fixed kill detection in start_slave_thread() by adding a check
after enter_cond().
sql/sql_class.cc:
Swapped order of kill and close in THD::awake().
Added comments.
sql/sql_class.h:
Added a comment to THD::killed.
sql/sql_parse.cc:
Added a sync point in do_command().
sql/sql_select.cc:
Added a sync point in JOIN::optimize().
case than in corr index".
Server was unable to find existing or explicitly created supporting
index for foreign key if corresponding statement clause used field
names in case different than one used in key specification and created
yet another supporting index.
In cases when name of constraint (and thus name of generated index)
was the same as name of existing/explicitly created index this led
to duplicate key name error.
The problem was that unlike all other code Key_part_spec::operator==()
compared field names in case sensitive fashion. As result routines
responsible for getting rid of redundant generated supporting indexes
for foreign key were not working properly for versions of field names
using different cases.
(backported from mysql-trunk)
sql/sql_class.cc:
Make field name comparison case-insensitive like it is
in the rest of server.
temp table
This patch introduces two key changes in the replication's behavior.
Firstly, it reverts part of BUG#51894 which puts any update to temporary tables
into the trx-cache. Now, updates to temporary tables are handled according to
the type of their engines as a regular table.
Secondly, an unsafe mixed statement, (i.e. a statement that access transactional
table as well non-transactional or temporary table, and writes to any of them),
are written into the trx-cache in order to minimize errors in the execution when
the statement logging format is in use.
Such changes has a direct impact on which statements are classified as unsafe
statements and thus part of BUG#53259 is reverted.
After BUG#36649, warnings for sub-statements are cleared when a
new sub-statement is started. This is problematic since it suppresses
warnings for unsafe statements in some cases. It is important that we
always give a warning to the client, because the user needs to know
when there is a risk that the slave goes out of sync.
We fixed the problem by generating warning messages for unsafe statements
while returning from a stored procedure, function, trigger or while
executing a top level statement.
We also started checking unsafeness when both performance and log tables are
used. This is necessary after the performance schema which does a distinction
between performance and log tables.
mysql-test/extra/rpl_tests/create_recursive_construct.inc:
Changed the order of the calls in the procedure because the code
that checks if a warning message is printed out expects that the
first statement gives an warning what is not the case for INSERT
INTO ta$CRC_ARG_level VALUES (47);
mysql-test/suite/binlog/r/binlog_stm_unsafe_warning.result:
Updated the result file.
mysql-test/suite/binlog/r/binlog_unsafe.result:
There are several changes here:
(1) - Changed the CREATE PROCEDURE $CRC.
(2) - The procedure $CRC was failing and the content of the binlog
was being printed out, after fix (1) the failure disappeared.
(3) - The warning message for unsafeness due to auto-increment collumns was
changed.
(4) - The warning message for unsafeness due to VERSION(), RAND() was changed.
mysql-test/suite/binlog/t/binlog_stm_unsafe_warning.test:
Tested filters.
mysql-test/suite/binlog/t/binlog_unsafe.test:
Reenabled the test case binlog_unsafe.
mysql-test/suite/binlog/t/disabled.def:
Reenabled the test case binlog_unsafe.
mysql-test/suite/rpl/r/rpl_begin_commit_rollback.result:
Updated the result file.
mysql-test/suite/rpl/r/rpl_non_direct_stm_mixing_engines.result:
Updated the result file.
mysql-test/suite/rpl/r/rpl_stm_auto_increment_bug33029.result:
Updated the result file.
sql/sql_class.cc:
Moved the stmt_accessed_table_flag variable and related information to the
LEX as we need the variable reset after each statement even inside a stored
procedure, what did not happen if the information was in the THD.
Changed the routine in the THD::binlog_query that prints the warning
messages to avoid trying to print them when inside a stored procedure,
function or trigger.
Checked for unsafeness when both performance and log tables where used.
After the introduction of the performance schema, we need to check both.
******
This patch fixes the following bugs:
- Bug#5889: Exit handler for a warning doesn't hide the warning in
trigger
- Bug#9857: Stored procedures: handler for sqlwarning ignored
- Bug#23032: Handlers declared in a SP do not handle warnings generated
in sub-SP
- Bug#36185: Incorrect precedence for warning and exception handlers
The problem was in the way warnings/errors during stored routine execution
were handled. Prior to this patch the logic was as follows:
- when a warning/an error happens: if we're executing a stored routine,
and there is a handler for that warning/error, remember the handler,
ignore the warning/error and continue execution.
- after a stored routine instruction is executed: check for a remembered
handler and activate one (if any).
This logic caused several problems:
- if one instruction generates several warnings (errors) it's impossible
to choose the right handler -- a handler for the first generated
condition was chosen and remembered for activation.
- mess with handling conditions in scopes different from the current one.
- not putting generated warnings/errors into Warning Info (Diagnostic
Area) is against The Standard.
The patch changes the logic as follows:
- Diagnostic Area is cleared on the beginning of each statement that
either is able to generate warnings, or is able to work with tables.
- at the end of a stored routine instruction, Diagnostic Area is left
intact.
- Diagnostic Area is checked after each stored routine instruction. If
an instruction generates several condition, it's now possible to take a
look at all of them and determine an appropriate handler.
mysql-test/r/signal.result:
Update result file:
1. handled conditions are not cleared any more;
2. reflect changes in signal.test
mysql-test/r/signal_demo3.result:
Update result file: handled conditions are not cleared any more.
Due to playing with max_error_count, resulting warning lists
have changed.
mysql-test/r/sp-big.result:
Update result file: handled conditions are not cleared any more.
mysql-test/r/sp-bugs.result:
Update result file: handled conditions are not cleared any more.
mysql-test/r/sp-code.result:
Update result file:
1. handled conditions are not cleared any more.
2. add result for a new test case in sp-code.test.
mysql-test/r/sp-error.result:
Update result file:
1. handled conditions are not cleared any more.
2. add result for a new test case in sp-error.test.
mysql-test/r/sp.result:
Update result file: handled conditions are not cleared any more.
mysql-test/r/sp_trans.result:
Update result file: handled conditions are not cleared any more.
mysql-test/r/strict.result:
Update result file: handled conditions are not cleared any more.
mysql-test/r/view.result:
Update result file: handled conditions are not cleared any more.
mysql-test/suite/funcs_1/r/innodb_storedproc_02.result:
Update result file: handled conditions are not cleared any more.
mysql-test/suite/funcs_1/r/memory_storedproc_02.result:
Update result file: handled conditions are not cleared any more.
mysql-test/suite/funcs_1/r/myisam_storedproc_02.result:
Update result file: handled conditions are not cleared any more.
mysql-test/suite/funcs_1/r/storedproc.result:
Update result file: handled conditions are not cleared any more.
mysql-test/suite/rpl/r/rpl_row_sp005.result:
Update result file: handled conditions are not cleared any more.
mysql-test/suite/rpl/r/rpl_row_sp006_InnoDB.result:
Update result file: handled conditions are not cleared any more.
mysql-test/suite/rpl/r/rpl_row_trig003.result:
Update result file: handled conditions are not cleared any more.
mysql-test/t/signal.test:
Make a test case more readable in the result file.
mysql-test/t/sp-code.test:
Add a test case for Bug#23032 checking that
No Data takes precedence on Warning.
mysql-test/t/sp-error.test:
Adding test cases for:
- Bug#23032
- Bug#36185
- Bug#5889
- Bug#9857
mysql-test/t/sp.test:
Fixing test case to reflect behavioral changes made by the patch.
sql/sp_head.cc:
Reset the per-statement warning count before executing
a stored procedure instruction.
Move to a separate function code which checks the
completion status of the executed statement and searches
for a handler.
Remove redundant code now that search for a handler is
done after execution, errors are always pushed.
sql/sp_pcontext.h:
Remove unused code.
sql/sp_rcontext.cc:
- Polish sp_rcontext::find_handler(): use sp_rcontext::m_hfound instead
of an extra local variable;
- Remove sp_rcontext::handle_condition();
- Introduce sp_rcontext::activate_handler(), which prepares
previously found handler for execution.
- Move sp_rcontext::enter_handler() code into activate_handler(),
because enter_handler() is used only from there;
- Cleanups;
- Introduce DBUG_EXECUTE_IF() for a test case in sp-code.test
sql/sp_rcontext.h:
- Remove unused code
- Cleanups
sql/sql_class.cc:
Merge THD::raise_condition_no_handler() into THD::raise_condition().
After the patch raise_condition_no_handler() was called
in raise_condition() only.
sql/sql_class.h:
Remove raise_condition_no_handler().
sql/sql_error.cc:
Remove Warning_info::reserve_space() -- handled conditions are not
cleared any more, so there is no need for RESIGNAL to re-push them.
sql/sql_error.h:
Remove Warning_info::reserve_space().
sql/sql_signal.cc:
Handled conditions are not cleared any more,
so there is no need for RESIGNAL to re-push them.
Remove dead and unused code.
Update to reflect the code review requests.
include/thr_lock.h:
Remove declarations for THR_LOCK_OWNER,
added along with the patch for sensitive cursors.
mysys/thr_lock.c:
Remove support for multiple thr_lock requestors
per THD.
sql/lock.cc:
Revert the patch that added support for sensitive cursors.
sql/sp_rcontext.cc:
Updated the use of mysql_open_cursor().
sql/sql_class.cc:
Move the instance of Server_side_cursor
from class Prepared_statement to class Statement.
sql/sql_class.h:
Move the isntance of Server_side_cursor
from class Prepared_statement to class
Statement.
Remove multiple lock_ids of thr_lock.
sql/sql_cursor.cc:
Remove Sensitive_cursor implementation.
sql/sql_cursor.h:
Remove declarations for sensitive cursors.
sql/sql_prepare.cc:
Move the declaration of instance of Server_side_cursor
from class Statement to class Prepared_statement,
where it's used.
sql/sql_select.cc:
Remove sensitive cursor support.
sql/sql_select.h:
Remove sensitive cursor support.
sql/sql_union.cc:
Remove sensitive cursor support.
This patch also fixes Bug#55452 "SET PASSWORD is
replicated twice in RBR mode".
The goal of this patch is to remove the release of
metadata locks from close_thread_tables().
This is necessary to not mistakenly release
the locks in the course of a multi-step
operation that involves multiple close_thread_tables()
or close_tables_for_reopen().
On the same token, move statement commit outside
close_thread_tables().
Other cleanups:
Cleanup COM_FIELD_LIST.
Don't call close_thread_tables() in COM_SHUTDOWN -- there
are no open tables there that can be closed (we leave
the locked tables mode in THD destructor, and this
close_thread_tables() won't leave it anyway).
Make open_and_lock_tables() and open_and_lock_tables_derived()
call close_thread_tables() upon failure.
Remove the calls to close_thread_tables() that are now
unnecessary.
Simplify the back off condition in Open_table_context.
Streamline metadata lock handling in LOCK TABLES
implementation.
Add asserts to ensure correct life cycle of
statement transaction in a session.
Remove a piece of dead code that has also become redundant
after the fix for Bug 37521.
mysql-test/r/variables.result:
Update results: set @@autocommit and statement transaction/
prelocked mode.
mysql-test/r/view.result:
A harmless change in CHECK TABLE <view> status for a broken view.
If previously a failure to prelock all functions used in a view
would leave the connection in LTM_PRELOCKED mode, now we call
close_thread_tables() from open_and_lock_tables()
and leave prelocked mode, thus some check in mysql_admin_table() that
works only in prelocked/locked tables mode is no longer activated.
mysql-test/suite/rpl/r/rpl_row_implicit_commit_binlog.result:
Fixed Bug#55452 "SET PASSWORD is replicated twice in
RBR mode": extra binlog events are gone from the
binary log.
mysql-test/t/variables.test:
Add a test case: set autocommit and statement transaction/prelocked
mode.
sql/event_data_objects.cc:
Simplify code in Event_job_data::execute().
Move sp_head memory management to lex_end().
sql/event_db_repository.cc:
Move the release of metadata locks outside
close_thread_tables().
Make sure we call close_thread_tables() when
open_and_lock_tables() fails and remove extra
code from the events data dictionary.
Use close_mysql_tables(), a new internal
function to properly close mysql.* tables
in the data dictionary.
Contract Event_db_repository::drop_events_by_field,
drop_schema_events into one function.
When dropping all events in a schema,
make sure we don't mistakenly release all
locks acquired by DROP DATABASE. These
include locks on the database name
and the global intention exclusive
metadata lock.
sql/event_db_repository.h:
Function open_event_table() does not require an instance
of Event_db_repository.
sql/events.cc:
Use close_mysql_tables() instead of close_thread_tables()
to bootstrap events, since the latter no longer
releases metadata locks.
sql/ha_ndbcluster.cc:
- mysql_rm_table_part2 no longer releases
acquired metadata locks. Do it in the caller.
sql/ha_ndbcluster_binlog.cc:
Deploy the new protocol for closing thread
tables in run_query() and ndb_binlog_index
code.
sql/handler.cc:
Assert that we never call ha_commit_trans/
ha_rollback_trans in sub-statement, which
is now the case.
sql/handler.h:
Add an accessor to check whether THD_TRANS object
is empty (has no transaction started).
sql/log.cc:
Update a comment.
sql/log_event.cc:
Since now we commit/rollback statement transaction in
mysql_execute_command(), we need a mechanism to communicate
from Query_log_event::do_apply_event() to mysql_execute_command()
that the statement transaction should be rolled back, not committed.
Ideally it would be a virtual method of THD. I hesitate
to make THD a virtual base class in this already large patch.
Use a thd->variables.option_bits for now.
Remove a call to close_thread_tables() from the slave IO
thread. It doesn't open any tables, and the protocol
for closing thread tables is more complicated now.
Make sure we properly close thread tables, however,
in Load_data_log_event, which doesn't
follow the standard server execution procedure
with mysql_execute_command().
@todo: this piece should use Server_runnable
framework instead.
Remove an unnecessary call to mysql_unlock_tables().
sql/rpl_rli.cc:
Update Relay_log_info::slave_close_thread_tables()
to follow the new close protocol.
sql/set_var.cc:
Remove an unused header.
sql/slave.cc:
Remove an unnecessary call to
close_thread_tables().
sql/sp.cc:
Remove unnecessary calls to close_thread_tables()
from SP DDL implementation. The tables will
be closed by the caller, in mysql_execute_command().
When dropping all routines in a database, make sure
to not mistakenly drop all metadata locks acquired
so far, they include the scoped lock on the schema.
sql/sp_head.cc:
Correct the protocol that closes thread tables
in an SP instruction.
Clear lex->sphead before cleaning up lex
with lex_end to make sure that we don't
delete the sphead twice. It's considered
to be "cleaner" and more in line with
future changes than calling delete lex->sphead
in other places that cleanup the lex.
sql/sp_head.h:
When destroying m_lex_keeper of an instruction,
don't delete the sphead that all lex objects
share.
@todo: don't store a reference to routine's sp_head
instance in instruction's lex.
sql/sql_acl.cc:
Don't call close_thread_tables() where the caller will
do that for us.
Fix Bug#55452 "SET PASSWORD is replicated twice in RBR
mode" by disabling RBR replication in change_password()
function.
Use close_mysql_tables() in bootstrap and ACL reload
code to make sure we release all metadata locks.
sql/sql_base.cc:
This is the main part of the patch:
- remove manipulation with thd->transaction
and thd->mdl_context from close_thread_tables().
Now this function is only responsible for closing
tables, nothing else.
This is necessary to be able to easily use
close_thread_tables() in procedures, that
involve multiple open/close tables, which all
need to be protected continuously by metadata
locks.
Add asserts ensuring that TABLE object
is only used when is protected by a metadata lock.
Simplify the back off condition of Open_table_context,
we no longer need to look at the autocommit mode.
Make open_and_lock_tables() and open_normal_and_derived_tables()
close thread tables and release metadata locks acquired so-far
upon failure. This simplifies their usage.
Implement close_mysql_tables().
sql/sql_base.h:
Add declaration for close_mysql_tables().
sql/sql_class.cc:
Remove a piece of dead code that has also become redundant
after the fix for Bug 37521.
The code became dead when my_eof() was made a non-protocol method,
but a method that merely modifies the diagnostics area.
The code became redundant with the fix for Bug#37521, when
we started to cal close_thread_tables() before
Protocol::end_statement().
sql/sql_do.cc:
Do nothing in DO if inside a substatement
(the assert moved out of trans_rollback_stmt).
sql/sql_handler.cc:
Add comments.
sql/sql_insert.cc:
Remove dead code.
Release metadata locks explicitly at the
end of the delayed insert thread.
sql/sql_lex.cc:
Add destruction of lex->sphead to lex_end(),
lex "reset" method called at the end of each statement.
sql/sql_parse.cc:
Move close_thread_tables() and other related
cleanups to mysql_execute_command()
from dispatch_command(). This has become
possible after the fix for Bug#37521.
Mark federated SERVER statements as DDL.
Next step: make sure that we don't store
eof packet in the query cache, and move
the query cache code outside mysql_parse.
Brush up the code of COM_FIELD_LIST.
Remove unnecessary calls to close_thread_tables().
When killing a query, don't report "OK"
if it was a suicide.
sql/sql_parse.h:
Remove declaration of a function that is now static.
sql/sql_partition.cc:
Remove an unnecessary call to close_thread_tables().
sql/sql_plugin.cc:
open_and_lock_tables() will clean up
after itself after a failure.
Move close_thread_tables() above
end: label, and replace with close_mysql_tables(),
which will also release the metadata lock
on mysql.plugin.
sql/sql_prepare.cc:
Now that we no longer release locks in close_thread_tables()
statement prepare code has become more straightforward.
Remove the now redundant check for thd->killed() (used
only by the backup project) from Execute_server_runnable.
Reorder code to take into account that now mysql_execute_command()
performs lex->unit.cleanup() and close_thread_tables().
sql/sql_priv.h:
Add a new option to server options to interact
between the slave SQL thread and execution
framework (hack). @todo: use a virtual
method of class THD instead.
sql/sql_servers.cc:
Due to Bug 25705 replication of
DROP/CREATE/ALTER SERVER is broken.
Make sure at least we do not attempt to
replicate these statements using RBR,
as this violates the assert in close_mysql_tables().
sql/sql_table.cc:
Do not release metadata locks in mysql_rm_table_part2,
this is done by the caller.
Do not call close_thread_tables() in mysql_create_table(),
this is done by the caller.
Fix a bug in DROP TABLE under LOCK TABLES when,
upon error in wait_while_table_is_used() we would mistakenly
release the metadata lock on a non-dropped table.
Explicitly release metadata locks when doing an implicit
commit.
sql/sql_trigger.cc:
Now that we delete lex->sphead in lex_end(),
zero the trigger's sphead in lex after loading
the trigger, to avoid double deletion.
sql/sql_udf.cc:
Use close_mysql_tables() instead of close_thread_tables().
sql/sys_vars.cc:
Remove code added in scope of WL#4284 which would
break when we perform set @@session.autocommit along
with setting other variables and using tables or functions.
A test case added to variables.test.
sql/transaction.cc:
Add asserts.
sql/tztime.cc:
Use close_mysql_tables() rather than close_thread_tables().
bytes_received/bytes_sent are ulonglong so they cannot be handled by the
ulong handling code in add_to_status/add_diff_to_status().
Fixed by adding code to handle these two variables in
add_to_status()/add_diff_to_status() and making sure they are not a subject
to the ulong handling code.
Essentially, the problem is that safemalloc is excruciatingly
slow as it checks all allocated blocks for overrun at each
memory management primitive, yielding a almost exponential
slowdown for the memory management functions (malloc, realloc,
free). The overrun check basically consists of verifying some
bytes of a block for certain magic keys, which catches some
simple forms of overrun. Another minor problem is violation
of aliasing rules and that its own internal list of blocks
is prone to corruption.
Another issue with safemalloc is rather the maintenance cost
as the tool has a significant impact on the server code.
Given the magnitude of memory debuggers available nowadays,
especially those that are provided with the platform malloc
implementation, maintenance of a in-house and largely obsolete
memory debugger becomes a burden that is not worth the effort
due to its slowness and lack of support for detecting more
common forms of heap corruption.
Since there are third-party tools that can provide the same
functionality at a lower or comparable performance cost, the
solution is to simply remove safemalloc. Third-party tools
can provide the same functionality at a lower or comparable
performance cost.
The removal of safemalloc also allows a simplification of the
malloc wrappers, removing quite a bit of kludge: redefinition
of my_malloc, my_free and the removal of the unused second
argument of my_free. Since free() always check whether the
supplied pointer is null, redudant checks are also removed.
Also, this patch adds unit testing for my_malloc and moves
my_realloc implementation into the same file as the other
memory allocation primitives.
client/mysqldump.c:
Pass my_free directly as its signature is compatible with the
callback type -- which wasn't the case for free_table_ent.
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.
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.
concurrently execute the statement XA START 'x', then mysqld
server could crash.
sql/sql_class.cc:
xid_cache_insert: added checking for element in cache before
insert it, return TRUE if such element already exists.
sql/sql_parse.cc:
mysql_execute_command modified:
* sequence of calls to xid_cache_search(..)/xid_cache_insert(...)
replaced by call to xid_cache_insert(...) in alternative
'case SQLCOM_XA_START:'
* added comment to alternative 'case SQLCOM_XA_COMMIT:'.
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.
an atomic counter"
Split the large LOCK_open section in open_table().
Do not call open_table_from_share() under LOCK_open.
Remove thd->version.
This fixes
Bug#50589 "Server hang on a query evaluated using a temporary
table"
Bug#51557 "LOCK_open and kernel_mutex are not happy together"
Bug#49463 "LOCK_table and innodb are not nice when handler
instances are created".
This patch has effect on storage engines that rely on
ha_open() PSEA method being called under LOCK_open.
In particular:
1) NDB is broken and left unfixed. NDB relies on LOCK_open
being kept as part of ha_open(), since it uses auto-discovery.
While previously the NDB open code was race-prone, now
it simply fails on asserts.
2) HEAP engine had a race in ha_heap::open() when
a share for the same table could be added twice
to the list of shares, or a dangling reference to a share
stored in HEAP handler. This patch aims to address this
problem by 'pinning' the newly created share in the
internal HEAP engine share list until at least one
handler instance is created using that share.
include/heap.h:
Add members to HP_CREATE_INFO.
Declare heap_release_share().
sql/lock.cc:
Remove thd->version, use thd->open_tables->s->version instead.
sql/repl_failsafe.cc:
Remove thd->version.
sql/sql_base.cc:
- close_thread_table(): move handler cleanup code outside the critical section protected by LOCK_open.
- remove thd->version
- split the large critical section in open_table() that
opens a new table from share and is protected by LOCK_open
into 2 critical sections, thus reducing the critical path.
- make check_if_table_exists() acquire LOCK_open internally.
- use thd->open_tables->s->version instead of thd->refresh_version to make sure that all tables in
thd->open_tables are in the same refresh series.
sql/sql_base.h:
Add declaration for check_if_table_exists().
sql/sql_class.cc:
Remove init_open_tables_state(), it's now equal to
reset_open_tables_state().
sql/sql_class.h:
Remove thd->version, THD::init_open_tables_state().
sql/sql_plugin.cc:
Use table->m_needs_reopen to mark the table as stale
rather than manipulate with thd->version, which is no more.
sql/sql_udf.cc:
Use table->m_needs_reopen to mark the table as stale
rather than manipulate with thd->version, which is no more.
sql/table.h:
Remove an unused variable.
sql/tztime.cc:
Use table->m_needs_reopen to mark the table as stale
rather than manipulate with thd->version, which is no more.
storage/heap/CMakeLists.txt:
Add heap tests to cmake build files.
storage/heap/ha_heap.cc:
Fix a race when ha_heap::ha_open() could insert two
HP_SHARE objects into the internal share list or store
a dangling reference to a share in ha_heap instance,
or wrongly set implicit_emptied.
storage/heap/hp_create.c:
Optionally pin a newly created share in the list of shares
by increasing its open_count. This is necessary to
make sure that a newly created share doesn't disappear while
a HP_INFO object is being created to reference it.
storage/heap/hp_open.c:
When adding a new HP_INFO object to the list of objects
in the heap share, make sure the open_count is not increased
twice.
storage/heap/hp_test1.c:
Adjust the test to new function signatures.
storage/heap/hp_test2.c:
Adjust the test to new function signatures.
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
In order to allow thread schedulers to be dynamically loaded,
it is necessary to make the following changes to the server:
- Two new service interfaces
- Modifications to InnoDB to inform the thread scheduler of state changes.
- Changes to the VIO subsystem for checking if data is available on a socket.
- Elimination of remains of the old thread pool implementation.
The two new service interfaces introduces are:
my_thread_scheduler
A service interface to register a thread
scheduler.
thd_wait
A service interface to inform thread scheduler
that the thread is about to start waiting.
In addition, the patch adds code that:
- Add a call to thd_wait for table locks in mysys
thd_lock.c by introducing a set function that
can be used to set a callback to be used when
waiting on a lock and resuming from waiting.
- Calling the mysys set function from the server
to set the callbacks correctly.
Fix various mismatches between function's language linkage. Any
particular function that is declared in C++ but should be callable
from C must have C linkage. Note that function types with different
linkages are also distinct. Thus, if a function type is declared in
C code, it will have C linkage (same if declared in a extern "C"
block).
client/mysql.cc:
Mismatch between prototype and declaration.
client/mysqltest.cc:
mysqltest used to be C code. Use C linkage where appropriate.
cmd-line-utils/readline/input.c:
Isolate unreachable code.
include/my_alloc.h:
Function type must have C linkage.
include/my_base.h:
Function type must have C linkage.
include/my_global.h:
Add helper macros to avoid spurious namespace indentation.
include/mysql.h.pp:
Update ABI file.
mysys/my_gethwaddr.c:
Remove stray carriage return and fix coding style.
plugin/semisync/semisync_master_plugin.cc:
Callback function types have C linkage.
plugin/semisync/semisync_slave_plugin.cc:
Callback function types have C linkage.
sql/derror.cc:
Expected function type has C linkage.
sql/field.cc:
Use helper macro and fix indentation.
sql/handler.cc:
Expected function type has C linkage.
sql/item_sum.cc:
Correct function linkages. Remove now unnecessary cast.
sql/item_sum.h:
Add prototypes with the appropriate linkage as otherwise they
are distinct.
sql/mysqld.cc:
Wrap functions in C linkage mode.
sql/opt_range.cc:
C language linkage is ignored for class member functions.
sql/partition_info.cc:
Add wrapper functions with C linkage for class member functions.
sql/rpl_utility.h:
Use helper macro and fix indentation.
sql/sql_class.cc:
Change type of thd argument -- THD is a class.
Use helper macro and fix indentation.
sql/sql_class.h:
Change type of thd argument -- THD is a class.
sql/sql_select.cc:
Expected function type has C linkage.
sql/sql_select.h:
Move prototype to sql_test.h
sql/sql_show.cc:
Expected function type has C linkage.
sql/sql_test.cc:
Fix required function prototype and fix coding style.
sql/sql_test.h:
Removed unnecessary export and add another.
storage/myisammrg/ha_myisammrg.cc:
Expected function type has C linkage.
storage/perfschema/pfs.cc:
PSI headers are declared with C language linkage, which also
applies to function types.
errors
In the fix of BUG#39934 in 5.1-rep+3, errors are generated when
binlog_format=row and a statement modifies a table restricted to
statement-logging (ER_BINLOG_ROW_MODE_AND_STMT_ENGINE); or if
binlog_format=statement and a statement modifies a table restricted to
row-logging (ER_BINLOG_STMT_MODE_AND_ROW_ENGINE).
However, some DDL statements that lock tables (e.g. ALTER TABLE,
CREATE INDEX and CREATE TRIGGER) were causing spurious errors,
although no row might be inserted into the binary log.
To fix the problem, we tagged statements that may generate
rows into the binary log and thence the warning messages are
only printed out when the appropriate conditions hold and rows
might be changed.
sql/log_event.cc:
Reorganized the Query_log_event's constructor based on the
CF_CAN_GENERATE_ROW_EVENTS flag and as such any statement
that has the associated flag should go through a cache
before being written to the binary log.
sql/share/errmsg-utf8.txt:
Improved the error message ER_BINLOG_UNSAFE_MIXED_STATEMENT according to Paul's
suggestion.
sql/sql_class.cc:
Created a hook to be used by innodb that checks if a statement
may write rows to the binary log. In other words, if it has
the CF_CAN_GENERATE_ROW_EVENTS flag associated.
sql/sql_class.h:
Defined the CF_CAN_GENERATE_ROW_EVENTS flag.
sql/sql_parse.cc:
Updated the sql_command_flags and added a function to check the
CF_CAN_GENERATE_ROW_EVENTS.
sql/sql_parse.h:
Added a function to check the CF_CAN_GENERATE_ROW_EVENTS.
storage/innobase/handler/ha_innodb.cc:
Added a call to the hook thd_generates_rows().
storage/innobase/handler/ha_innodb.h:
Defined an external reference to the hook thd_generates_rows().
The thd->variables.option_bits & OPTION_BIN_LOG is currently abused:
it's both a system variable and an implementation switch. The current
approach to this option bit breaks the session variable encapsulation.
Besides it is allowed to change @@session.sql_bin_log within a
transaction what may lead to not correctly logging a transaction.
To fix the problems, we created a thd->variables variable to represent
the "sql_log_bin" and prohibited its update inside a transaction or
sub-statement.
mysql-test/suite/binlog/r/binlog_stm_unsafe_warning.result:
Updated result file. The reason the warnings are removed is
related to BUG#50312.
mysql-test/suite/binlog/r/binlog_switch_inside_trans.result:
Checks when is possible to change the option @@session.sql_log_bin.
mysql-test/suite/binlog/t/binlog_switch_inside_trans.test:
Checks when is possible to change the option @@session.sql_log_bin.
mysql-test/suite/rpl/r/rpl_non_direct_stm_mixing_engines.result:
Updated the result file with warnings that were being printed
due to the wrong use of the thd->variables.option_bits and
sql_log_bin_top_level variables.
mysql-test/suite/rpl/r/rpl_stm_mixing_engines.result:
Updated the result file with warnings that were being printed
due to the wrong use of the thd->variables.option_bits and
sql_log_bin_top_level variables.
sql/share/errmsg-utf8.txt:
Introduces two error messages to notify that the @@session.sql_log_bin
cannot be changed inside a sub-statement or transaction.
sql/sql_base.cc:
Removes the variable sql_log_bin_toplevel and uses
the session variable sql_log_bin.
sql/sql_class.cc:
Replaces the variable sql_log_bin_toplevel by the
(variables.option_bits & OPTION_BIN_LOG).
sql/sql_class.h:
Removes the variable sql_log_bin_toplevel and creates
a session variable sql_log_bin.
sql/sys_vars.cc:
Checks when the sql_log_bin can be correctly updated.
