The problem is a race between a session closing its vio
(i.e. after a COM_QUIT) at the same time it is being killed by
another thread. This could trigger a assertion in vio_close()
as the two threads could end up closing the same vio, at the
same time. This could happen due to the implementation of
SIGNAL_WITH_VIO_CLOSE, which closes the vio of the thread
being killed.
The solution is to serialize the close of the Vio under
LOCK_thd_data, which protects THD data.
No regression test is added as this is essentially a debug
issue and the test case would be quite convoluted as we would
need to synchronize a session that is being killed -- which
is a bit difficult since debug sync points code does not
synchronize killed sessions.
sql/mysqld.cc:
Drop lock parameter from close_connection, its not necessary
any more. The newly introduced THD::disconnect method will take
care of locking.
sql/mysqld.h:
Change prototype, add a default parameter for the error code.
sql/sql_class.cc:
In case SIGNAL_WITH_VIO_CLOSE is defined, the active vio is
closed and cleared. Subsequent calls will only close the vio
owned by the session.
Fixed the references to security_ctx->priv_user
to be real char * pointers instead of a C array name reference.
This is somehow important for some 3d party
dtrace replacements
include/mysql/plugin_audit.h:
Connection auditing class.
include/mysql/plugin_audit.h.pp:
Connection auditing class.
sql/mysqld.cc:
Notify disconnect to auditing.
sql/sql_audit.cc:
Connection class event dispatcher.
sql/sql_audit.h:
mysql_audit_notify() is not available in embedded.
sql/sql_connect.cc:
Notify connect to auditing.
sql/sql_parse.cc:
Notify user change to auditing.
--Bug#52157 various crashes and assertions with multi-table update, stored function
--Bug#54475 improper error handling causes cascading crashing failures in innodb/ndb
--Bug#57703 create view cause Assertion failed: 0, file .\item_subselect.cc, line 846
--Bug#57352 valgrind warnings when creating view
--Recently discovered problem when a nested materialized derived table is used
before being populated and it leads to incorrect result
We have several modes when we should disable subquery evaluation.
The reasons for disabling are different. It could be
uselessness of the evaluation as in case of 'CREATE VIEW'
or 'PREPARE stmt', or we should disable subquery evaluation
if tables are not locked yet as it happens in bug#54475, or
too early evaluation of subqueries can lead to wrong result
as it happened in Bug#19077.
Main problem is that if subquery items are treated as const
they are evaluated in ::fix_fields(), ::fix_length_and_dec()
of the parental items as a lot of these methods have
Item::val_...() calls inside.
We have to make subqueries non-const to prevent unnecessary
subquery evaluation. At the moment we have different methods
for this. Here is a list of these modes:
1. PREPARE stmt;
We use UNCACHEABLE_PREPARE flag.
It is set during parsing in sql_parse.cc, mysql_new_select() for
each SELECT_LEX object and cleared at the end of PREPARE in
sql_prepare.cc, init_stmt_after_parse(). If this flag is set
subquery becomes non-const and evaluation does not happen.
2. CREATE|ALTER VIEW, SHOW CREATE VIEW, I_S tables which
process FRM files
We use LEX::view_prepare_mode field. We set it before
view preparation and check this flag in
::fix_fields(), ::fix_length_and_dec().
Some bugs are fixed using this approach,
some are not(Bug#57352, Bug#57703). The problem here is
that we have a lot of ::fix_fields(), ::fix_length_and_dec()
where we use Item::val_...() calls for const items.
3. Derived tables with subquery = wrong result(Bug19077)
The reason of this bug is too early subquery evaluation.
It was fixed by adding Item::with_subselect field
The check of this field in appropriate places prevents
const item evaluation if the item have subquery.
The fix for Bug19077 fixes only the problem with
convert_constant_item() function and does not cover
other places(::fix_fields(), ::fix_length_and_dec() again)
where subqueries could be evaluated.
Example:
CREATE TABLE t1 (i INT, j BIGINT);
INSERT INTO t1 VALUES (1, 2), (2, 2), (3, 2);
SELECT * FROM (SELECT MIN(i) FROM t1
WHERE j = SUBSTRING('12', (SELECT * FROM (SELECT MIN(j) FROM t1) t2))) t3;
DROP TABLE t1;
4. Derived tables with subquery where subquery
is evaluated before table locking(Bug#54475, Bug#52157)
Suggested solution is following:
-Introduce new field LEX::context_analysis_only with the following
possible flags:
#define CONTEXT_ANALYSIS_ONLY_PREPARE 1
#define CONTEXT_ANALYSIS_ONLY_VIEW 2
#define CONTEXT_ANALYSIS_ONLY_DERIVED 4
-Set/clean these flags when we perform
context analysis operation
-Item_subselect::const_item() returns
result depending on LEX::context_analysis_only.
If context_analysis_only is set then we return
FALSE that means that subquery is non-const.
As all subquery types are wrapped by Item_subselect
it allow as to make subquery non-const when
it's necessary.
mysql-test/r/derived.result:
test case
mysql-test/r/multi_update.result:
test case
mysql-test/r/view.result:
test case
mysql-test/suite/innodb/r/innodb_multi_update.result:
test case
mysql-test/suite/innodb/t/innodb_multi_update.test:
test case
mysql-test/suite/innodb_plugin/r/innodb_multi_update.result:
test case
mysql-test/suite/innodb_plugin/t/innodb_multi_update.test:
test case
mysql-test/t/derived.test:
test case
mysql-test/t/multi_update.test:
test case
mysql-test/t/view.test:
test case
sql/item.cc:
--removed unnecessary code
sql/item_cmpfunc.cc:
--removed unnecessary checks
--THD::is_context_analysis_only() is replaced with LEX::is_ps_or_view_context_analysis()
sql/item_func.cc:
--refactored context analysis checks
sql/item_row.cc:
--removed unnecessary checks
sql/item_subselect.cc:
--removed unnecessary code
--added DBUG_ASSERT into Item_subselect::exec()
which asserts that subquery execution can not happen
if LEX::context_analysis_only is set, i.e. at context
analysis stage.
--Item_subselect::const_item()
Return FALSE if LEX::context_analysis_only is set.
It prevents subquery evaluation in ::fix_fields &
::fix_length_and_dec at context analysis stage.
sql/item_subselect.h:
--removed unnecessary code
sql/mysql_priv.h:
--Added new set of flags.
sql/sql_class.h:
--removed unnecessary code
sql/sql_derived.cc:
--added LEX::context_analysis_only analysis intialization/cleanup
sql/sql_lex.cc:
--init LEX::context_analysis_only field
sql/sql_lex.h:
--New LEX::context_analysis_only field
sql/sql_parse.cc:
--removed unnecessary code
sql/sql_prepare.cc:
--removed unnecessary code
--added LEX::context_analysis_only analysis intialization/cleanup
sql/sql_select.cc:
--refactored context analysis checks
sql/sql_show.cc:
--added LEX::context_analysis_only analysis intialization/cleanup
sql/sql_view.cc:
--added LEX::context_analysis_only analysis intialization/cleanup
Manual merge from mysql-5.1-bugteam into mysql-5.5-bugteam.
Conflicts
=========
Text conflict in sql/log.cc
Text conflict in sql/log.h
Text conflict in sql/slave.cc
Text conflict in sql/sql_parse.cc
Text conflict in sql/sql_priv.h
when generating new name.
If find_uniq_filename returns an error, then this error is not
being propagated upwards, and execution does not report error to
the user (although a entry in the error log is generated).
Additionally, some more errors were ignored in new_file_impl:
- when writing the rotate event
- when reopening the index and binary log file
This patch addresses this by propagating the error up in the
execution stack. Furthermore, when rotation of the binary log
fails, an incident event is written, because there may be a
chance that some changes for a given statement, were not properly
logged. For example, in SBR, LOAD DATA INFILE statement requires
more than one event to be logged, should rotation fail while
logging part of the LOAD DATA events, then the logged data would
become inconsistent with the data in the storage engine.
mysql-test/include/restart_mysqld.inc:
Refactored restart_mysqld so that it is not hardcoded for
mysqld.1, but rather for the current server.
mysql-test/suite/binlog/t/binlog_index.test:
The error on open of index and binary log on new_file_impl
is now caught. Thence the user will get an error message.
We need to accomodate this change in the test case for the
failing FLUSH LOGS.
mysql-test/suite/rpl/t/rpl_binlog_errors-master.opt:
Sets max_binlog_size to 4096.
mysql-test/suite/rpl/t/rpl_binlog_errors.test:
Added some test cases for asserting that the error is found
and reported.
sql/handler.cc:
Catching error now returned by unlog (in ha_commit_trans) and
returning it.
sql/log.cc:
Propagating errors from new_file_impl upwards. The errors that
new_file_impl catches now are:
- error on generate_new_name
- error on writing the rotate event
- error when opening the index or the binary log file.
sql/log.h:
Changing declaration of:
- rotate_and_purge
- new_file
- new_file_without_locking
- new_file_impl
- unlog
They now return int instead of void.
sql/mysql_priv.h:
Change signature of reload_acl_and_cache so that write_to_binlog
is an int instead of bool.
sql/mysqld.cc:
Redeclaring not_used var as int instead of bool.
sql/rpl_injector.cc:
Changes to catch the return from rotate_and_purge.
sql/slave.cc:
Changes to catch the return values for new_file and rotate_relay_log.
sql/slave.h:
Changes to rotate_relay_log declaration (now returns int
instead of void).
sql/sql_load.cc:
In SBR, some logging of LOAD DATA events goes through
IO_CACHE_CALLBACK invocation at mf_iocache.c:_my_b_get. The
IO_CACHE implementation is ignoring the return value for from
these callbacks (pre_read and post_read), so we need to find out
at the end of the execution if the error is set or not in THD.
sql/sql_parse.cc:
Catching the rotate_relay_log and rotate_and_purge return values.
Semantic change in reload_acl_and_cache so that we report errors
in binlog interactions through the write_to_binlog output parameter.
If there was any failure while rotating the binary log, we should
then report the error to the client when handling SQLCOMM_FLUSH.
Problem: Extended characters outside of ASCII range where not displayed
properly in SHOW PROCESSLIST, because thd_info->query was always sent as
system_character_set (utf8). This was wrong, because query buffer
is never converted to utf8 - it is always have client character set.
Fix: sending query buffer using query character set
@ sql/sql_class.cc
@ sql/sql_class.h
Introducing a new class CSET_STRING, a LEX_STRING with character set.
Adding set_query(&CSET_STRING)
Adding reset_query(), to use instead of set_query(0, NULL).
@ sql/event_data_objects.cc
Using reset_query()
@ sql/log_event.cc
Using reset_query()
Adding charset argument to set_query_and_id().
@ sql/slave.cc
Using reset_query().
@ sql/sp_head.cc
Changing backing up and restore code to use CSET_STRING.
@ sql/sql_audit.h
Using CSET_STRING.
In the "else" branch it's OK not to use
global_system_variables.character_set_client.
&my_charset_latin1, which is set in constructor, is fine
(verified with Sergey Vojtovich).
@ sql/sql_insert.cc
Using set_query() with proper character set: table_name is utf8.
@ sql/sql_parse.cc
Adding character set argument to set_query_and_id().
(This is the main point where thd->charset() is stored
into thd->query_string.cs, for use in "SHOW PROCESSLIST".)
Using reset_query().
@ sql/sql_prepare.cc
Storing client character set into thd->query_string.cs.
@ sql/sql_show.cc
Using CSET_STRING to fetch and send charset-aware query information
from threads.
@ storage/myisam/ha_myisam.cc
Using set_query() with proper character set: table_name is utf8.
@ mysql-test/r/show_check.result
@ mysql-test/t/show_check.test
Adding tests
Finalize the server flags after any kind of command is executed.
To avoid updating the flag multiple times, reorganize code so that
its invoked only once for each command.
sql/log_event.cc:
Explicit update after the query is executed in the slave.
sql/sql_parse.cc:
Reorganize so that the status flag is updated for any command and
not done twice for a query command.
network when a query was slow.
When a query is slow, sent a special flag to the client
indicating this fact.
Add a test case.
Implement review comments.
include/mysql_com.h:
Clear SERVER_QUERY_WAS_SLOW at end of each statement.
Since this patch removes the technique when
thd->server_status is modified briefly only to
execute my_eof(), reset more server status
bit that may remain in the status from
execution of the previous statement.
sql/protocol.cc:
Always use thd->server_status to
in net_* functions to send the latest
status to the client.
sql/sp_head.cc:
Calculate if a query was slow before
sending EOF packet.
sql/sql_cursor.cc:
Remove juggling with thd->server_status.
The extra status bits are reset at
start of the next statement.
sql/sql_db.cc:
Remove juggling with thd->server_status.
The extra status bits are reset at
start of the next statement.
sql/sql_error.cc:
Remove m_server_status member,
it's not really part of the Diagnostics_area.
sql/sql_error.h:
Remove server_status member, it's
not part of the Diagnostics_area.
The associated hack is removed as well.
sql/sql_parse.cc:
Do not calculate if a query was
slow twice. Use a status flag in thd->server_status.
tests/mysql_client_test.c:
Add a test case for Bug#57058.
Check that the status is present
at the client, when sent.
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().
set to 128k.
sql/sp.cc:
Added checking for stack overrun at functions
db_load_routine/sp_find_routine.
sql/sp_head.cc:
sp_head::execute() modified: pass constant value STACK_MIN_SIZE
instead of 8 * STACK_MIN_SIZE as second argument value
in call to check_stack_overrun. Added checking for stack overrun
at functions sp_lex_keeper::reset_lex_and_exec_core/sp_instr_stmt::execute.
sql/sql_parse.cc:
check_stack_overrun modified: allocate buffer for error message
at heap instead of stack.
parse_sql modified: added call to check_stack_overrun() before
parsing of sql statement.
replication aborts
When recieving a 'SLAVE STOP' command, slave SQL thread will roll back the
transaction and stop immidiately if there is only transactional table updated,
even through 'CREATE|DROP TEMPOARY TABLE' statement are in it. But These
statements can never be rolled back. Because the temporary tables to the user
session mapping remain until 'RESET SLAVE', Therefore it will abort SQL thread
with an error that the table already exists or doesn't exist, when it restarts
and executes the whole transaction again.
After this patch, SQL thread always waits till the transaction ends and then stops,
if 'CREATE|DROP TEMPOARY TABLE' statement are in it.
mysql-test/extra/rpl_tests/rpl_stop_slave.test:
Auxiliary file which is used to test this bug.
mysql-test/suite/rpl/t/rpl_stop_slave.test:
Test case for this bug.
sql/slave.cc:
Checking if OPTION_KEEP_LOG is set. If it is set, SQL thread should wait
until the transaction ends.
sql/sql_parse.cc:
Add a debug point for testing this bug.
discover its existence".
The problem was that user without any privileges on
routine was able to find out whether it existed or not.
DROP FUNCTION and DROP PROCEDURE statements were
checking if routine being dropped existed and reported
ER_SP_DOES_NOT_EXIST error/warning before checking
if user had enough privileges to drop it.
This patch solves this problem by changing code not to
check if routine exists before checking if user has enough
privileges to drop it. Moreover we no longer perform this
check using a separate call instead we rely on
sp_drop_routine() returning SP_KEY_NOT_FOUND if routine
doesn't exist.
This change also simplifies one of upcoming patches
refactoring global read lock implementation.
mysql-test/r/grant.result:
Updated test case after fixing bug#57061 "User without
privilege on routine can discover its existence". Removed
DROP PROCEDURE/FUNCTION statements which have started to
fail after this fix (correctly). There is no need in
dropping routines in freshly created database anyway.
mysql-test/r/sp-security.result:
Added new test case for bug#57061 "User without privilege
on routine can discover its existence". Updated existing
tests according to new behaviour.
mysql-test/suite/funcs_1/r/innodb_storedproc_06.result:
Updated test case after fixing bug#57061 "User without
privilege on routine can discover its existence".
Now we drop routines under user which has enough
privileges to do so.
mysql-test/suite/funcs_1/r/memory_storedproc_06.result:
Updated test case after fixing bug#57061 "User without
privilege on routine can discover its existence".
Now we drop routines under user which has enough
privileges to do so.
mysql-test/suite/funcs_1/r/myisam_storedproc_06.result:
Updated test case after fixing bug#57061 "User without
privilege on routine can discover its existence".
Now we drop routines under user which has enough
privileges to do so.
mysql-test/suite/funcs_1/storedproc/storedproc_06.inc:
Updated test case after fixing bug#57061 "User without
privilege on routine can discover its existence".
Now we drop routines under user which has enough
privileges to do so.
mysql-test/t/grant.test:
Updated test case after fixing bug#57061 "User without
privilege on routine can discover its existence". Removed
DROP PROCEDURE/FUNCTION statements which have started to
fail after this fix (correctly). There is no need in
dropping routines in freshly created database anyway.
mysql-test/t/sp-security.test:
Added new test case for bug#57061 "User without privilege
on routine can discover its existence". Updated existing
tests according to new behaviour.
sql/sp.cc:
Removed sp_routine_exists_in_table() which is no longer
used.
sql/sp.h:
Removed sp_routine_exists_in_table() which is no longer
used.
sql/sql_parse.cc:
When dropping routine we no longer check if routine exists
before checking if user has enough privileges to do so.
Moreover we no longer perform this check using a separate
call instead we rely on sp_drop_routine() returning
SP_KEY_NOT_FOUND if routine doesn't exist.
Bug#54678: InnoDB, TRUNCATE, ALTER, I_S SELECT, crash or deadlock
- Incompatible change: truncate no longer resorts to a row by
row delete if the storage engine does not support the truncate
method. Consequently, the count of affected rows does not, in
any case, reflect the actual number of rows.
- Incompatible change: it is no longer possible to truncate a
table that participates as a parent in a foreign key constraint,
unless it is a self-referencing constraint (both parent and child
are in the same table). To work around this incompatible change
and still be able to truncate such tables, disable foreign checks
with SET foreign_key_checks=0 before truncate. Alternatively, if
foreign key checks are necessary, please use a DELETE statement
without a WHERE condition.
Problem description:
The problem was that for storage engines that do not support
truncate table via a external drop and recreate, such as InnoDB
which implements truncate via a internal drop and recreate, the
delete_all_rows method could be invoked with a shared metadata
lock, causing problems if the engine needed exclusive access
to some internal metadata. This problem originated with the
fact that there is no truncate specific handler method, which
ended up leading to a abuse of the delete_all_rows method that
is primarily used for delete operations without a condition.
Solution:
The solution is to introduce a truncate handler method that is
invoked when the engine does not support truncation via a table
drop and recreate. This method is invoked under a exclusive
metadata lock, so that there is only a single instance of the
table when the method is invoked.
Also, the method is not invoked and a error is thrown if
the table is a parent in a non-self-referencing foreign key
relationship. This was necessary to avoid inconsistency as
some integrity checks are bypassed. This is inline with the
fact that truncate is primarily a DDL operation that was
designed to quickly remove all data from a table.
mysql-test/suite/innodb/t/innodb-truncate.test:
Add test cases for truncate and foreign key checks.
Also test that InnoDB resets auto-increment on truncate.
mysql-test/suite/innodb/t/innodb.test:
FK is not necessary, test is related to auto-increment.
Update error number, truncate is no longer invoked if
table is parent in a FK relationship.
mysql-test/suite/innodb/t/innodb_mysql.test:
Update error number, truncate is no longer invoked if
table is parent in a FK relationship.
Use delete instead of truncate, test is used to check
the interaction of FKs, triggers and delete.
mysql-test/suite/parts/inc/partition_check.inc:
Fix typo.
mysql-test/suite/sys_vars/t/foreign_key_checks_func.test:
Update error number, truncate is no longer invoked if
table is parent in a FK relationship.
mysql-test/t/mdl_sync.test:
Modify test case to reflect and ensure that truncate takes
a exclusive metadata lock.
mysql-test/t/trigger-trans.test:
Update error number, truncate is no longer invoked if
table is parent in a FK relationship.
sql/ha_partition.cc:
Reorganize the various truncate methods. delete_all_rows is now
passed directly to the underlying engines, so as truncate. The
code responsible for truncating individual partitions is moved
to ha_partition::truncate_partition, which is invoked when a
ALTER TABLE t1 TRUNCATE PARTITION p statement is executed.
Since the partition truncate no longer can be invoked via
delete, the bitmap operations are not necessary anymore. The
explicit reset of the auto-increment value is also removed
as the underlying engines are now responsible for reseting
the value.
sql/handler.cc:
Wire up the handler truncate method.
sql/handler.h:
Introduce and document the truncate handler method. It assumes
certain use cases of delete_all_rows.
Add method to retrieve the list of foreign keys referencing a
table. Method is used to avoid truncating tables that are
parent in a foreign key relationship.
sql/share/errmsg-utf8.txt:
Add error message for truncate and FK.
sql/sql_lex.h:
Introduce a flag so that the partition engine can detect when
a partition is being truncated. Used to give a special error.
sql/sql_parse.cc:
Function mysql_truncate_table no longer exists.
sql/sql_partition_admin.cc:
Implement the TRUNCATE PARTITION statement.
sql/sql_truncate.cc:
Change the truncate table implementation to use the new truncate
handler method and to not rely on row-by-row delete anymore.
The truncate handler method is always invoked with a exclusive
metadata lock. Also, it is no longer possible to truncate a
table that is parent in some non-self-referencing foreign key.
storage/archive/ha_archive.cc:
Rename method as the description indicates that in the future
this could be a truncate operation.
storage/blackhole/ha_blackhole.cc:
Implement truncate as no operation for the blackhole engine in
order to remain compatible with older releases.
storage/federated/ha_federated.cc:
Introduce truncate method that invokes delete_all_rows.
This is required to support partition truncate as this
form of truncate does not implement the drop and recreate
protocol.
storage/heap/ha_heap.cc:
Introduce truncate method that invokes delete_all_rows.
This is required to support partition truncate as this
form of truncate does not implement the drop and recreate
protocol.
storage/ibmdb2i/ha_ibmdb2i.cc:
Introduce truncate method that invokes delete_all_rows.
This is required to support partition truncate as this
form of truncate does not implement the drop and recreate
protocol.
storage/innobase/handler/ha_innodb.cc:
Rename delete_all_rows to truncate. InnoDB now does truncate
under a exclusive metadata lock.
Introduce and reorganize methods used to retrieve the list
of foreign keys referenced by a or referencing a table.
storage/myisammrg/ha_myisammrg.cc:
Introduce truncate method that invokes delete_all_rows.
This is required in order to remain compatible with earlier
releases where truncate would resort to a row-by-row delete.
REPAIR of merge table
Bug #56422 CHECK TABLE run when the table is locked reports
corruption along with timeout
The crash happened if a table maintenance statement (ANALYZE TABLE,
REPAIR TABLE, etc.) was executed on a MERGE table and opening and
locking a child table failed. This could for example happen if a child
table did not exist or if a lock timeout happened while waiting for
a conflicting metadata lock to disappear.
Since opening and locking the MERGE table and its children failed,
the tables would be closed and the metadata locks released.
However, TABLE_LIST::table for the MERGE table would still be set,
with its value invalid since the tables had been closed.
This caused the table maintenance statement to try to continue
and upgrade the metadata lock on the MERGE table. But since the lock
already had been released, this caused a segfault.
This patch fixes the problem by setting TABLE_LIST::table to NULL
if open_and_lock_tables() fails. This prevents maintenance
statements from continuing and trying to upgrade the metadata lock.
The patch includes a 5.5 version of the fix for
Bug #46339 crash on REPAIR TABLE merge table USE_FRM.
This bug caused REPAIR TABLE ... USE_FRM to give an assert
when used on merge tables.
The patch also enables the CHECK TABLE statement for log tables.
Before, CHECK TABLE for log tables gave ER_CANT_LOCK_LOG_TABLE,
yet still counted the statement as successfully executed.
With the changes to table maintenance statement error handling
in this patch, CHECK TABLE would no longer be considered as
successful in this case. This would have caused upgrade scripts
to mistakenly think that the general and slow logs are corrupted
and have to be repaired. Enabling CHECK TABLES for log tables
prevents this from happening.
Finally, the patch changes the error message from "Corrupt" to
"Operation failed" for a number of issues not related to table
corruption. For example "Lock wait timeout exceeded" and
"Deadlock found trying to get lock".
Test cases added to merge.test and check.test.
check_merge_table_access() used to do two things:
- set proper database for every merge table child;
- check SELECT | UPDATE | DELETE for merge table children.
Setting database is not needed anymore, since it's done
on the parsing stage.
Thus, check_merge_table_access() can be removed;
needed privileges can be checked using check_table_access().
to allow temp table operations) -- prerequisite patch #2.
Introduce a new form of find_temporary_table() function:
find_temporary_table() by a table key. It will be used
in further patches.
Replace find_temporary_table(table_list->db, table_list->name)
by more appropiate find_temporary_table(table_list) across
the codebase.
'CREATE TABLE IF NOT EXISTS ... SELECT' behaviour
BUG#47132, BUG#47442, BUG49494, BUG#23992 and BUG#48814 will disappear
automatically after the this patch.
BUG#55617 is fixed by this patch too.
This is the 5.5 part.
It implements:
- 'CREATE TABLE IF NOT EXISTS ... SELECT' statement will not insert
anything and binlog anything if the table already exists.
It only generate a warning that table already exists.
- A couple of test cases for the behavior changing.
'CREATE TABLE IF NOT EXISTS ... SELECT' behaviour
BUG#55474, BUG#55499, BUG#55598, BUG#55616 and BUG#55777 are fixed
in this patch too.
This is the 5.1 part.
It implements:
- if the table exists, binlog two events: CREATE TABLE IF NOT EXISTS
and INSERT ... SELECT
- Insert nothing and binlog nothing on master if the existing object
is a view. It only generates a warning that table already exists.
mysql-test/r/trigger.result:
Ather this patch, 'CREATE TABLE IF NOT EXISTS ... SELECT' will not
insert anything if the creating table already exists and is a view.
sql/sql_class.h:
Declare virtual function write_to_binlog() for select_insert.
It's used to binlog 'create select'
sql/sql_insert.cc:
Implement write_to_binlog();
Use write_to_binlog() instead of binlog_query() to binlog the statement.
if the table exists, binlog two events: CREATE TABLE IF NOT EXISTS
and INSERT ... SELECT
sql/sql_lex.h:
Declare create_select_start_with_brace and create_select_pos.
They are helpful for binlogging 'create select'
sql/sql_parse.cc:
Do nothing on master if the existing object is a view.
sql/sql_yacc.yy:
Record the relative postion of 'SELECT' in the 'CREATE ...SELECT' statement.
Record whether there is a '(' before the 'SELECT' clause.
locks on the table
Fixing the partitioning specifics after TRUNCATE TABLE in
bug-42643 was fixed.
Reorganize of code to decrease the size of the giant switch
in mysql_execute_command, and to prepare for future parser
reengineering. Moved code into Sql_statement objects.
Updated patch according to davi's review comments.
libmysqld/CMakeLists.txt:
Added new files.
libmysqld/Makefile.am:
Added new files.
mysql-test/r/not_partition.result:
now returning error on partitioning commands
if partitioning is not enabled.
mysql-test/r/partition_disabled.result:
There is no partition handlerton, so it cannot
find the specified engine in the .frm file.
mysql-test/r/partition_truncate.result:
Updated test results.
mysql-test/suite/parts/inc/partition_mgm.inc:
Added check that TRUNCATE PARTITION does not delete on failure.
mysql-test/suite/parts/r/partition_debug_sync_innodb.result:
updated results.
mysql-test/suite/parts/r/partition_mgm_lc0_archive.result:
updated results.
mysql-test/suite/parts/r/partition_mgm_lc1_archive.result:
updated results.
mysql-test/suite/parts/r/partition_mgm_lc2_archive.result:
updated results.
mysql-test/suite/parts/t/partition_debug_sync_innodb.test:
Test case for this bug.
mysql-test/t/not_partition.test:
Added check for TRUNCATE PARTITION without partitioning.
mysql-test/t/partition_truncate.test:
Added test of TRUNCATE PARTITION on non partitioned table.
sql/CMakeLists.txt:
Added new files.
sql/Makefile.am:
Added new files.
sql/datadict.cc:
Moved out the storage engine check into an own
function, including assert for lock.
sql/datadict.h:
added dd_frm_storage_engine.
sql/sql_alter_table.cc:
moved the code for SQLCOM_ALTER_TABLE in mysql_execute_command
into its own file, and using the Sql_statement object to
prepare for future parser reengineering.
sql/sql_alter_table.h:
Created Sql_statement object for ALTER TABLE.
sql/sql_lex.cc:
resetting m_stmt.
sql/sql_lex.h:
Temporary hack for forward declaration of enum_alter_table_change_level.
sql/sql_parse.cc:
Moved out ALTER/ANALYZE/CHECK/OPTIMIZE/REPAIR TABLE
from the giant switch into their own Sql_statement
objects.
sql/sql_parse.h:
Exporting check_merge_table_access.
sql/sql_partition_admin.cc:
created Sql_statement for
ALTER TABLE t ANALYZE/CHECK/OPTIMIZE/REPAIR/TRUNCATE
PARTITION. To be able to reuse the TABLE equivalents.
sql/sql_partition_admin.h:
Added Sql_statement of partition admin statements.
sql/sql_table.cc:
Moved table maintenance code into sql_table_maintenance.cc
sql/sql_table.h:
Moved table maintenance code into sql_table_maintenance.h
exporting functions used by sql_table_maintenance.
sql/sql_table_maintenance.cc:
Moved table maintenance code from sql_table.cc
sql/sql_table_maintenance.h:
Sql_statement objects for ANALYZE/CHECK/OPTIMIZE/REPAIR TABLE.
Also declaring the keycache functions.
sql/sql_truncate.cc:
Moved code from SQLCOM_TRUNCATE in mysql_execute_command into
Truncate_statement::execute.
Added check for partitioned table on TRUNCATE PARTITION.
Moved locking fix for partitioned table into
Alter_table_truncate_partition::execute.
sql/sql_truncate.h:
Truncate_statement declaration (sub class of Sql_statement).
sql/sql_yacc.yy:
Using the new Sql_statment objects.
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.
Remove acquisition of LOCK_open around file system operations,
since such operations are now protected by metadata locks.
Rework table discovery algorithm to not require LOCK_open.
No new tests added since all MDL locking operations are covered
in lock.test and mdl_sync.test, and as long as these tests
pass despite the increased concurrency, consistency must be
unaffected.
mysql-test/t/disabled.def:
Disable NDB tests due to Bug#55799.
sql/datadict.cc:
No longer necessary to protect ha_create_table() with
LOCK_open. Serial execution is now ensured by metadata
locks.
sql/ha_ndbcluster.cc:
Do not manipulate with LOCK_open in cluster code.
sql/ha_ndbcluster_binlog.cc:
Do not manipulate with LOCK_open in cluster code.
sql/ha_ndbcluster_binlog.h:
Update function signature.
sql/handler.cc:
Implement ha_check_if_table_exists().
@todo: some engines provide ha_table_exists_in_engine()
handlerton call, for those we perhaps shouldn't
call ha_discover(), to be more efficient.
Since currently it's only NDB, postpone till
integration with NDB.
sql/handler.h:
Declare ha_check_if_table_exists() function.
sql/mdl.cc:
Remove an obsolete comment.
sql/sql_base.cc:
Update to a new signature of close_cached_tables():
from now on we always call it without LOCK_open.
Update comments.
Remove get_table_share_with_create(), we should
not attempt to create a table under LOCK_open.
Introduce get_table_share_with_discover() instead,
which would request a back off action if the table
exists in engine.
Remove acquisition of LOCK_open for
data dictionary operations, such as check_if_table_exists().
Do not use get_table_share_with_create/discover for views,
where it's not needed.
Make tdc_remove_table() optionally acquire LOCK_open
to simplify usage of this function.
Use the right mutex in the partitioning code when
manipulating with thd->open_tables.
sql/sql_base.h:
Update signatures of changes functions.
sql/sql_insert.cc:
Do not wrap quick_rm_table() with LOCK_open acquisition,
this is unnecessary.
sql/sql_parse.cc:
Update to the new calling convention of tdc_remove_table().
Update to the new signature of close_cached_tables().
Update comments.
sql/sql_rename.cc:
Update to the new calling convention of tdc_remove_table().
Remove acquisition of LOCK_open around filesystem
operations.
sql/sql_show.cc:
Remove get_trigger_table_impl().
Do not acquire LOCK_open for a dirty read of the trigger
file.
sql/sql_table.cc:
Do not acquire LOCK_open for filesystem operations.
sql/sql_trigger.cc:
Do not require LOCK_open for trigger file I/O.
sql/sql_truncate.cc:
Update to the new signature of tdc_remove_table().
sql/sql_view.cc:
Do not require LOCK_open for view I/O.
Use tdc_remove_table() to expel view share.
Update comments.
sql/sys_vars.cc:
Update to the new signature of close_cached_tables().
/*![:version:] Query Code */, where [:version:] is a sequence of 5
digits representing the mysql server version(e.g /*!50200 ... */),
is a special comment that the query in it can be executed on those
servers whose versions are larger than the version appearing in the
comment. It leads to a security issue when slave's version is larger
than master's. A malicious user can improve his privileges on slaves.
Because slave SQL thread is running with SUPER privileges, so it can
execute queries that he/she does not have privileges on master.
This bug is fixed with the logic below:
- To replace '!' with ' ' in the magic comments which are not applied on
master. So they become common comments and will not be applied on slave.
- Example:
'INSERT INTO t1 VALUES (1) /*!10000, (2)*/ /*!99999 ,(3)*/
will be binlogged as
'INSERT INTO t1 VALUES (1) /*!10000, (2)*/ /* 99999 ,(3)*/
mysql-test/suite/rpl/t/rpl_conditional_comments.test:
Test the patch for this bug.
sql/mysql_priv.h:
Rename inBuf as rawBuf and remove the const limitation.
sql/sql_lex.cc:
To replace '!' with ' ' in the magic comments which are not applied on
master.
sql/sql_lex.h:
Remove the const limitation on parameter buff, as it can be modified in the function since
this patch.
Add member function yyUnput for Lex_input_stream. It set a character back the query buff.
sql/sql_parse.cc:
Rename inBuf as rawBuf and remove the const limitation.
sql/sql_partition.cc:
Remove the const limitation on parameter part_buff, as it can be modified in the function since
this patch.
sql/sql_partition.h:
Remove the const limitation on parameter part_buff, as it can be modified in the function since
this patch.
sql/table.h:
Remove the const limitation on variable partition_info, as it can be modified since
this patch.
