"HANDLER statements within a transaction might lead to deadlocks".
Introduce a notion of a sentinel to MDL_context. A sentinel
is a ticket that separates all tickets in the context into two
groups: before and after it. Currently we can have (and need) only
one designated sentinel -- it separates all locks taken by LOCK
TABLE or HANDLER statement, which must survive COMMIT and ROLLBACK
and all other locks, which must be released at COMMIT or ROLLBACK.
The tricky part is maintaining the sentinel up to date when
someone release its corresponding ticket. This can happen, e.g.
if someone issues DROP TABLE under LOCK TABLES (generally,
see all calls to release_all_locks_for_name()).
MDL_context::release_ticket() is modified to take care of it.
******
A fix and a test case for Bug#46224 "HANDLER statements within a
transaction might lead to deadlocks".
An attempt to mix HANDLER SQL statements, which are transaction-
agnostic, an open multi-statement transaction,
and DDL against the involved tables (in a concurrent connection)
could lead to a deadlock. The deadlock would occur when
HANDLER OPEN or HANDLER READ would have to wait on a conflicting
metadata lock. If the connection that issued HANDLER statement
also had other metadata locks (say, acquired in scope of a
transaction), a classical deadlock situation of mutual wait
could occur.
Incompatible change: entering LOCK TABLES mode automatically
closes all open HANDLERs in the current connection.
Incompatible change: previously an attempt to wait on a lock
in a connection that has an open HANDLER statement could wait
indefinitely/deadlock. After this patch, an error ER_LOCK_DEADLOCK
is produced.
The idea of the fix is to merge thd->handler_mdl_context
with the main mdl_context of the connection, used for transactional
locks. This makes deadlock detection possible, since all waits
with locks are "visible" and available to analysis in a single
MDL context of the connection.
Since HANDLER locks and transactional locks have a different life
cycle -- HANDLERs are explicitly open and closed, and so
are HANDLER locks, explicitly acquired and released, whereas
transactional locks "accumulate" till the end of a transaction
and are released only with COMMIT, ROLLBACK and ROLLBACK TO SAVEPOINT,
a concept of "sentinel" was introduced to MDL_context.
All locks, HANDLER and others, reside in the same linked list.
However, a selected element of the list separates locks with
different life cycle. HANDLER locks always reside at the
end of the list, after the sentinel. Transactional locks are
prepended to the beginning of the list, before the sentinel.
Thus, ROLLBACK, COMMIT or ROLLBACK TO SAVEPOINT, only
release those locks that reside before the sentinel. HANDLER locks
must be released explicitly as part of HANDLER CLOSE statement,
or an implicit close.
The same approach with sentinel
is also employed for LOCK TABLES locks. Since HANDLER and LOCK TABLES
statement has never worked together, the implementation is
made simple and only maintains one sentinel, which is used either
for HANDLER locks, or for LOCK TABLES locks.
Bug#16565 mysqld --help --verbose does not order variablesBug#20413 sql_slave_skip_counter is not shown in show variables
Bug#20415 Output of mysqld --help --verbose is incomplete
Bug#25430 variable not found in SELECT @@global.ft_max_word_len;
Bug#32902 plugin variables don't know their names
Bug#34599 MySQLD Option and Variable Reference need to be consistent in formatting!
Bug#34829 No default value for variable and setting default does not raise error
Bug#34834 ? Is accepted as a valid sql mode
Bug#34878 Few variables have default value according to documentation but error occurs
Bug#34883 ft_boolean_syntax cant be assigned from user variable to global var.
Bug#37187 `INFORMATION_SCHEMA`.`GLOBAL_VARIABLES`: inconsistent status
Bug#40988 log_output_basic.test succeeded though syntactically false.
Bug#41010 enum-style command-line options are not honoured (maria.maria-recover fails)
Bug#42103 Setting key_buffer_size to a negative value may lead to very large allocations
Bug#44691 Some plugins configured as MYSQL_PLUGIN_MANDATORY in can be disabled
Bug#44797 plugins w/o command-line options have no disabling option in --help
Bug#46314 string system variables don't support expressions
Bug#46470 sys_vars.max_binlog_cache_size_basic_32 is broken
Bug#46586 When using the plugin interface the type "set" for options caused a crash.
Bug#47212 Crash in DBUG_PRINT in mysqltest.cc when trying to print octal number
Bug#48758 mysqltest crashes on sys_vars.collation_server_basic in gcov builds
Bug#49417 some complaints about mysqld --help --verbose output
Bug#49540 DEFAULT value of binlog_format isn't the default value
Bug#49640 ambiguous option '--skip-skip-myisam' (double skip prefix)
Bug#49644 init_connect and \0
Bug#49645 init_slave and multi-byte characters
Bug#49646 mysql --show-warnings crashes when server dies
CMakeLists.txt:
Bug#44691 Some plugins configured as MYSQL_PLUGIN_MANDATORY in can be disabled
client/mysql.cc:
don't crash with --show-warnings when mysqld dies
config/ac-macros/plugins.m4:
Bug#44691 Some plugins configured as MYSQL_PLUGIN_MANDATORY in can be disabled
include/my_getopt.h:
comments
include/my_pthread.h:
fix double #define
mysql-test/mysql-test-run.pl:
run sys_vars suite by default
properly recognize envirinment variables (e.g. MTR_MAX_SAVE_CORE) set to 0
escape gdb command line arguments
mysql-test/suite/sys_vars/r/rpl_init_slave_func.result:
init_slave+utf8 bug
mysql-test/suite/sys_vars/t/rpl_init_slave_func.test:
init_slave+utf8 bug
mysys/my_getopt.c:
Bug#34599 MySQLD Option and Variable Reference need to be consistent in formatting!
Bug#46586 When using the plugin interface the type "set" for options caused a crash.
Bug#49640 ambiguous option '--skip-skip-myisam' (double skip prefix)
mysys/typelib.c:
support for flagset
sql/ha_ndbcluster.cc:
backport from telco tree
sql/item_func.cc:
Bug#49644 init_connect and \0
Bug#49645 init_slave and multi-byte characters
sql/sql_builtin.cc.in:
Bug#44691 Some plugins configured as MYSQL_PLUGIN_MANDATORY in can be disabled
sql/sql_plugin.cc:
Bug#44691 Some plugins configured as MYSQL_PLUGIN_MANDATORY in can be disabled
Bug#32902 plugin variables don't know their names
Bug#44797 plugins w/o command-line options have no disabling option in --help
sql/sys_vars.cc:
all server variables are defined here
storage/myisam/ft_parser.c:
remove unnecessary updates of param->quot
storage/myisam/ha_myisam.cc:
myisam_* variables belong here
strings/my_vsnprintf.c:
%o and %llx
unittest/mysys/my_vsnprintf-t.c:
%o and %llx tests
vio/viosocket.c:
bugfix: fix @@wait_timeout to work with socket timeouts (vs. alarm thread)
Bug#16565 mysqld --help --verbose does not order variablesBug#20413 sql_slave_skip_counter is not shown in show variables
Bug#20415 Output of mysqld --help --verbose is incomplete
Bug#25430 variable not found in SELECT @@global.ft_max_word_len;
Bug#32902 plugin variables don't know their names
Bug#34599 MySQLD Option and Variable Reference need to be consistent in formatting!
Bug#34829 No default value for variable and setting default does not raise error
Bug#34834 ? Is accepted as a valid sql mode
Bug#34878 Few variables have default value according to documentation but error occurs
Bug#34883 ft_boolean_syntax cant be assigned from user variable to global var.
Bug#37187 `INFORMATION_SCHEMA`.`GLOBAL_VARIABLES`: inconsistent status
Bug#40988 log_output_basic.test succeeded though syntactically false.
Bug#41010 enum-style command-line options are not honoured (maria.maria-recover fails)
Bug#42103 Setting key_buffer_size to a negative value may lead to very large allocations
Bug#44691 Some plugins configured as MYSQL_PLUGIN_MANDATORY in can be disabled
Bug#44797 plugins w/o command-line options have no disabling option in --help
Bug#46314 string system variables don't support expressions
Bug#46470 sys_vars.max_binlog_cache_size_basic_32 is broken
Bug#46586 When using the plugin interface the type "set" for options caused a crash.
Bug#47212 Crash in DBUG_PRINT in mysqltest.cc when trying to print octal number
Bug#48758 mysqltest crashes on sys_vars.collation_server_basic in gcov builds
Bug#49417 some complaints about mysqld --help --verbose output
Bug#49540 DEFAULT value of binlog_format isn't the default value
Bug#49640 ambiguous option '--skip-skip-myisam' (double skip prefix)
Bug#49644 init_connect and \0
Bug#49645 init_slave and multi-byte characters
Bug#49646 mysql --show-warnings crashes when server dies
WL#3771
"Audit Plugin Interface"
Implement new plug-in type - AUDIT
New plug-in: audit_null
simply increments counter for how many times it was called.
include/Makefile.am:
wl3771
add new headers to distribution
include/mysql/plugin.h:
wl3771
define new AUDIT plugin type
Split out fulltext plugin type into its own header
include/mysql/plugin.h.pp:
wl3771
no real API change, just re-arranged some code
include/mysql/plugin_audit.h:
wl3771
pluggable audit interface
include/mysql/plugin_ftparser.h:
wl3771
Split out fulltext plugin type into its own header
libmysqld/CMakeLists.txt:
wl3771
add sql_audit.cc to build
libmysqld/Makefile.am:
wl3771
add sql_audit.cc to build
plugin/audit_null:
wl3771
an example plugin for testing pluggable audit interface
plugin/audit_null/Makefile.am:
wl3771
an example plugin for testing pluggable audit interface
plugin/audit_null/audit_null.c:
wl3771
an example plugin for testing pluggable audit interface
plugin/audit_null/plug.in:
wl3771
an example plugin for testing pluggable audit interface
sql/CMakeLists.txt:
wl3771
add sql_audit.cc to build
sql/Makefile.am:
wl3771
add sql_audit.cc to build
sql/event_queue.cc:
wl3771
release audit resources before waiting
sql/log.cc:
wl3771
add general audit call for log
sql/mysqld.cc:
wl3771
add audit initialize/finalize
add general audit call for error
sql/sql_audit.cc:
wl3771
pluggable audit interface implementation
sql/sql_audit.h:
wl3771
pluggable audit interface implementation
sql/sql_class.cc:
wl3771
add thd audit init/deinit calls
sql/sql_class.h:
wl3771
add required data structures for audit to THD
sql/sql_connect.cc:
wl3771
release audit resources before waiting
sql/sql_insert.cc:
wl3771
release audit plugins before waiting
sql/sql_parse.cc:
wl3771
add general audit call for results
sql/sql_plugin.cc:
wl3771
add declarations for audit plugin type
WL#3771
"Audit Plugin Interface"
Implement new plug-in type - AUDIT
New plug-in: audit_null
simply increments counter for how many times it was called.
Introduce a counter for protection against global read lock on thread level.
The functions for protection against global read lock sometimes need a local
variable to signal when the protection is set, and hence need to be released.
It would be better to control this behaviour via a counter on the THD struct,
telling how many times the protection has been claimed by the current thread.
A side-effect of the fix is that if protection is claimed twice for a thread,
only a simple increment is required for the second claim, instead of a
mutex-protected increment of the global variable protect_against_global_read_lock.
sql/lock.cc:
Count how many times that we have claimed protection against global read lock.
Assert that we really have the protection when releasing it.
Added comments to all functions operating on global_read_lock.
sql/sql_class.cc:
Added the counter variable global_read_lock_protection.
sql/sql_class.h:
Added the counter variable global_read_lock_protection.
sql/sql_parse.cc:
Replaced test on local variable need_start_waiting with test on
thd->global_read_lock_protection.
sql/sql_table.cc:
Replaced test on local variable need_start_waiting with test on
thd->global_read_lock_protection.
sql/sql_trigger.cc:
Inserted test on thd->global_read_lock_protection.
Introduce a counter for protection against global read lock on thread level.
The functions for protection against global read lock sometimes need a local
variable to signal when the protection is set, and hence need to be released.
It would be better to control this behaviour via a counter on the THD struct,
telling how many times the protection has been claimed by the current thread.
A side-effect of the fix is that if protection is claimed twice for a thread,
only a simple increment is required for the second claim, instead of a
mutex-protected increment of the global variable protect_against_global_read_lock.
----------------------------------------------------------
revno: 2617.69.20
committer: Konstantin Osipov <kostja@sun.com>
branch nick: 5.4-4284-1-assert
timestamp: Thu 2009-08-13 18:29:55 +0400
message:
WL#4284 "Transactional DDL locking"
A review fix.
Since WL#4284 implementation separated MDL_request and MDL_ticket,
MDL_request becamse a utility object necessary only to get a ticket.
Store it by-value in TABLE_LIST with the intent to merge
MDL_request::key with table_list->table_name and table_list->db
in future.
Change the MDL subsystem to not require MDL_requests to
stay around till close_thread_tables().
Remove the list of requests from the MDL context.
Requests for shared metadata locks acquired in open_tables()
are only used as a list in recover_from_failed_open_table_attempt(),
which calls mdl_context.wait_for_locks() for this list.
To keep such list for recover_from_failed_open_table_attempt(),
introduce a context class (Open_table_context), that collects
all requests.
A lot of minor cleanups and simplications that became possible
with this change.
sql/event_db_repository.cc:
Remove alloc_mdl_requests(). Now MDL_request instance is a member
of TABLE_LIST, and init_one_table() initializes it.
sql/ha_ndbcluster_binlog.cc:
Remove now unnecessary declaration and initialization
of binlog_mdl_request.
sql/lock.cc:
No need to allocate MDL requests in lock_table_names() now.
sql/log.cc:
Use init_one_table() method, remove alloc_mdl_requests(),
which is now unnecessary.
sql/log_event.cc:
No need to allocate mdl_request separately now.
Use init_one_table() method.
sql/log_event_old.cc:
Update to the new signature of close_tables_for_reopen().
sql/mdl.cc:
Update try_acquire_exclusive_lock() to be more easy to use.
Function lock_table_name_if_not_cached() has been removed.
Make acquire_shared_lock() signature consistent with
try_acquire_exclusive_lock() signature.
Remove methods that are no longer used.
Update comments.
sql/mdl.h:
Implement an assignment operator that doesn't
copy MDL_key (MDL_key::operator= is private and
should remain private).
This is a hack to work-around assignment of TABLE_LIST
by value in several places. Such assignments violate
encapsulation, since only perform a shallow copy.
In most cases these assignments are a hack on their own.
sql/mysql_priv.h:
Update signatures of close_thread_tables() and close_tables_for_reopen().
sql/sp.cc:
Allocate TABLE_LIST in thd->mem_root.
Use init_one_table().
sql/sp_head.cc:
Use init_one_table().
Remove thd->locked_tables_root, it's no longer needed.
sql/sql_acl.cc:
Use init_mdl_requests() and init_one_table().
sql/sql_base.cc:
Update to new signatures of try_acquire_shared_lock() and
try_acquire_exclusive_lock().
Remove lock_table_name_if_not_cached().
Fix a bug in open_ltable() that would not return ER_LOCK_DEADLOCK
in case of a failed lock_tables() and a multi-statement
transaction.
Fix a bug in open_and_lock_tables_derived() that would
not return ER_LOCK_DEADLOCK in case of a multi-statement
transaction and a failure of lock_tables().
Move assignment of enum_open_table_action to a method of Open_table_context, a new class that maintains information
for backoff actions.
Minor rearrangements of the code.
Remove alloc_mdl_requests() in functions that work with system
tables: instead the patch ensures that callers always initialize
TABLE_LIST argument.
sql/sql_class.cc:
THD::locked_tables_root is no more.
sql/sql_class.h:
THD::locked_tables_root is no more.
Add a declaration for Open_table_context class.
sql/sql_delete.cc:
Update to use the simplified MDL API.
sql/sql_handler.cc:
TABLE_LIST::mdl_request is stored by-value now.
Ensure that mdl_request.ticket is NULL for every request
that is passed into MDL, to satisfy MDL asserts.
@ sql/sql_help.cc
Function open_system_tables_for_read() no longer initializes
mdl_requests.
Move TABLE_LIST::mdl_request initialization closer to
TABLE_LIST initialization.
sql/sql_help.cc:
Function open_system_tables_for_read() no longer initializes
mdl_requests.
Move TABLE_LIST::mdl_request initialization closer to
TABLE_LIST initialization.
sql/sql_insert.cc:
Remove assignment by-value of TABLE_LIST in
TABLEOP_HOOKS. We can't carry over a granted
MDL ticket from one table list to another.
sql/sql_parse.cc:
Change alloc_mdl_requests() -> init_mdl_requests().
@todo We can remove init_mdl_requests() altogether
in some places: all places that call add_table_to_list()
already have mdl requests initialized.
sql/sql_plugin.cc:
Use init_one_table().
THD::locked_tables_root is no more.
sql/sql_servers.cc:
Use init_one_table().
sql/sql_show.cc:
Update acquire_high_priority_shared_lock() to use
TABLE_LIST::mdl_request rather than allocate an own.
Fix get_trigger_table_impl() to use init_one_table(),
check for out of memory, follow the coding style.
sql/sql_table.cc:
Update to work with TABLE_LIST::mdl_request by-value.
Remove lock_table_name_if_not_cached().
The code that used to delegate to it is quite simple and
concise without it now.
sql/sql_udf.cc:
Use init_one_table().
sql/sql_update.cc:
Update to use the new signature of close_tables_for_reopen().
sql/table.cc:
Move re-setting of mdl_requests for prepared statements
and stored procedures from close_thread_tables() to
reinit_stmt_before_use().
Change alloc_mdl_requests() to init_mdl_requests().
init_mdl_requests() is a hack that can't be deleted
until we don't have a list-aware TABLE_LIST constructor.
Hopefully its use will be minimal
sql/table.h:
Change alloc_mdl_requests() to init_mdl_requests()
TABLE_LIST::mdl_request is stored by value.
sql/tztime.cc:
We no longer initialize mdl requests in open_system_tables_for*()
functions. Move this initialization closer to initialization
of the rest of TABLE_LIST members.
storage/myisammrg/ha_myisammrg.cc:
Simplify mdl_request initialization.
----------------------------------------------------------
revno: 2617.69.20
committer: Konstantin Osipov <kostja@sun.com>
branch nick: 5.4-4284-1-assert
timestamp: Thu 2009-08-13 18:29:55 +0400
message:
WL#4284 "Transactional DDL locking"
A review fix.
Since WL#4284 implementation separated MDL_request and MDL_ticket,
MDL_request becamse a utility object necessary only to get a ticket.
Store it by-value in TABLE_LIST with the intent to merge
MDL_request::key with table_list->table_name and table_list->db
in future.
Change the MDL subsystem to not require MDL_requests to
stay around till close_thread_tables().
Remove the list of requests from the MDL context.
Requests for shared metadata locks acquired in open_tables()
are only used as a list in recover_from_failed_open_table_attempt(),
which calls mdl_context.wait_for_locks() for this list.
To keep such list for recover_from_failed_open_table_attempt(),
introduce a context class (Open_table_context), that collects
all requests.
A lot of minor cleanups and simplications that became possible
with this change.
2617.31.12, 2617.31.15, 2617.31.15, 2617.31.16, 2617.43.1
- initial changeset that introduced the fix for
Bug#989 and follow up fixes for all test suite failures
introduced in the initial changeset.
------------------------------------------------------------
revno: 2617.31.1
committer: Davi Arnaut <Davi.Arnaut@Sun.COM>
branch nick: 4284-6.0
timestamp: Fri 2009-03-06 19:17:00 -0300
message:
Bug#989: If DROP TABLE while there's an active transaction, wrong binlog order
WL#4284: Transactional DDL locking
Currently the MySQL server does not keep metadata locks on
schema objects for the duration of a transaction, thus failing
to guarantee the integrity of the schema objects being used
during the transaction and to protect then from concurrent
DDL operations. This also poses a problem for replication as
a DDL operation might be replicated even thought there are
active transactions using the object being modified.
The solution is to defer the release of metadata locks until
a active transaction is either committed or rolled back. This
prevents other statements from modifying the table for the
entire duration of the transaction. This provides commitment
ordering for guaranteeing serializability across multiple
transactions.
- Incompatible change:
If MySQL's metadata locking system encounters a lock conflict,
the usual schema is to use the try and back-off technique to
avoid deadlocks -- this schema consists in releasing all locks
and trying to acquire them all in one go.
But in a transactional context this algorithm can't be utilized
as its not possible to release locks acquired during the course
of the transaction without breaking the transaction commitments.
To avoid deadlocks in this case, the ER_LOCK_DEADLOCK will be
returned if a lock conflict is encountered during a transaction.
Let's consider an example:
A transaction has two statements that modify table t1, then table
t2, and then commits. The first statement of the transaction will
acquire a shared metadata lock on table t1, and it will be kept
utill COMMIT to ensure serializability.
At the moment when the second statement attempts to acquire a
shared metadata lock on t2, a concurrent ALTER or DROP statement
might have locked t2 exclusively. The prescription of the current
locking protocol is that the acquirer of the shared lock backs off
-- gives up all his current locks and retries. This implies that
the entire multi-statement transaction has to be rolled back.
- Incompatible change:
FLUSH commands such as FLUSH PRIVILEGES and FLUSH TABLES WITH READ
LOCK won't cause locked tables to be implicitly unlocked anymore.
mysql-test/extra/binlog_tests/drop_table.test:
Add test case for Bug#989.
mysql-test/extra/binlog_tests/mix_innodb_myisam_binlog.test:
Fix test case to reflect the fact that transactions now hold
metadata locks for the duration of a transaction.
mysql-test/include/mix1.inc:
Fix test case to reflect the fact that transactions now hold
metadata locks for the duration of a transaction.
mysql-test/include/mix2.inc:
Fix test case to reflect the fact that transactions now hold
metadata locks for the duration of a transaction.
mysql-test/r/flush_block_commit.result:
Update test case result (WL#4284).
mysql-test/r/flush_block_commit_notembedded.result:
Update test case result (WL#4284).
mysql-test/r/innodb.result:
Update test case result (WL#4284).
mysql-test/r/innodb_mysql.result:
Update test case result (WL#4284).
mysql-test/r/lock.result:
Add test case result for an effect of WL#4284/Bug#989
(all locks should be released when a connection terminates).
mysql-test/r/mix2_myisam.result:
Update test case result (effects of WL#4284/Bug#989).
mysql-test/r/not_embedded_server.result:
Update test case result (effects of WL#4284/Bug#989).
Add a test case for interaction of WL#4284 and FLUSH PRIVILEGES.
mysql-test/r/partition_innodb_semi_consistent.result:
Update test case result (effects of WL#4284/Bug#989).
mysql-test/r/partition_sync.result:
Temporarily disable the test case for Bug#43867,
which will be fixed by a subsequent backport.
mysql-test/r/ps.result:
Add a test case for effect of PREPARE on transactional
locks: we take a savepoint at beginning of PREAPRE
and release it at the end. Thus PREPARE does not
accumulate metadata locks (Bug#989/WL#4284).
mysql-test/r/read_only_innodb.result:
Update test case result (effects of WL#4284/Bug#989).
mysql-test/suite/binlog/r/binlog_row_drop_tbl.result:
Add a test case result (WL#4284/Bug#989).
mysql-test/suite/binlog/r/binlog_row_mix_innodb_myisam.result:
Update test case result (effects of WL#4284/Bug#989).
mysql-test/suite/binlog/r/binlog_stm_drop_tbl.result:
Add a test case result (WL#4284/Bug#989).
mysql-test/suite/binlog/r/binlog_stm_mix_innodb_myisam.result:
Update test case result (effects of WL#4284/Bug#989).
mysql-test/suite/binlog/r/binlog_unsafe.result:
A side effect of Bug#989 -- slightly different table map ids.
mysql-test/suite/binlog/t/binlog_row_drop_tbl.test:
Add a test case for WL#4284/Bug#989.
mysql-test/suite/binlog/t/binlog_stm_drop_tbl.test:
Add a test case for WL#4284/Bug#989.
mysql-test/suite/binlog/t/binlog_stm_row.test:
Update to the new state name. This
is actually a follow up to another patch for WL#4284,
that changes Locked thread state to Table lock.
mysql-test/suite/ndb/r/ndb_index_ordered.result:
Remove result for disabled part of the test case.
mysql-test/suite/ndb/t/disabled.def:
Temporarily disable a test case (Bug#45621).
mysql-test/suite/ndb/t/ndb_index_ordered.test:
Disable a part of a test case (needs update to
reflect semantics of Bug#989).
mysql-test/suite/rpl/t/disabled.def:
Disable tests made meaningless by transactional metadata
locking.
mysql-test/suite/sys_vars/r/autocommit_func.result:
Add a commit (Bug#989).
mysql-test/suite/sys_vars/t/autocommit_func.test:
Add a commit (Bug#989).
mysql-test/t/flush_block_commit.test:
Fix test case to reflect the fact that transactions now hold
metadata locks for the duration of a transaction.
mysql-test/t/flush_block_commit_notembedded.test:
Fix test case to reflect the fact that transactions now hold
metadata locks for the duration of a transaction.
Add a test case for transaction-scope locks and the global
read lock (Bug#989/WL#4284).
mysql-test/t/innodb.test:
Fix test case to reflect the fact that transactions now hold
metadata locks for the duration of a transaction
(effects of Bug#989/WL#4284).
mysql-test/t/lock.test:
Add a test case for Bug#989/WL#4284.
mysql-test/t/not_embedded_server.test:
Add a test case for Bug#989/WL#4284.
mysql-test/t/partition_innodb_semi_consistent.test:
Replace TRUNCATE with DELETE, to not issue
an implicit commit of a transaction, and not depend
on metadata locks.
mysql-test/t/partition_sync.test:
Temporarily disable the test case for Bug#43867,
which needs a fix to be backported from 6.0.
mysql-test/t/ps.test:
Add a test case for semantics of PREPARE and transaction-scope
locks: metadata locks on tables used in PREPARE are enclosed into a
temporary savepoint, taken at the beginning of PREPARE,
and released at the end. Thus PREPARE does not effect
what locks a transaction owns.
mysql-test/t/read_only_innodb.test:
Fix test case to reflect the fact that transactions now hold
metadata locks for the duration of a transaction
(Bug#989/WL#4284).
Wait for the read_only statement to actually flush tables before
sending other concurrent statements that depend on its state.
mysql-test/t/xa.test:
Fix test case to reflect the fact that transactions now hold
metadata locks for the duration of a transaction
(Bug#989/WL#4284).
sql/ha_ndbcluster_binlog.cc:
Backport bits of changes of ha_ndbcluster_binlog.cc
from 6.0, to fix the failing binlog test suite with
WL#4284. WL#4284 implementation does not work
with 5.1 implementation of ndbcluster binlog index.
sql/log_event.cc:
Release metadata locks after issuing a commit.
sql/mdl.cc:
Style changes (WL#4284).
sql/mysql_priv.h:
Rename parameter to match the name used in the definition (WL#4284).
sql/rpl_injector.cc:
Release metadata locks on commit (WL#4284).
sql/rpl_rli.cc:
Remove assert made meaningless, metadata locks are released
at the end of the transaction.
sql/set_var.cc:
Close tables and release locks if autocommit mode is set.
sql/slave.cc:
Release metadata locks after a rollback.
sql/sql_acl.cc:
Don't implicitly unlock locked tables. Issue a implicit commit
at the end and unlock tables.
sql/sql_base.cc:
Defer the release of metadata locks when closing tables
if not required to.
Issue a deadlock error if the locking protocol requires
that a transaction re-acquire its locks.
Release metadata locks when closing tables for reopen.
sql/sql_class.cc:
Release metadata locks if the thread is killed.
sql/sql_parse.cc:
Release metadata locks after implicitly committing a active
transaction, or after explicit commits or rollbacks.
sql/sql_plugin.cc:
Allocate MDL request on the stack as the use of the table
is contained within the function. It will be removed from
the context once close_thread_tables is called at the end
of the function.
sql/sql_prepare.cc:
The problem is that the prepare phase of the CREATE TABLE
statement takes a exclusive metadata lock lock and this can
cause a self-deadlock the thread already holds a shared lock
on the table being that should be created.
The solution is to make the prepare phase take a shared
metadata lock when preparing a CREATE TABLE statement. The
execution of the statement will still acquire a exclusive
lock, but won't cause any problem as it issues a implicit
commit.
After some discussions with stakeholders it has been decided that
metadata locks acquired during a PREPARE statement must be released
once the statement is prepared even if it is prepared within a multi
statement transaction.
sql/sql_servers.cc:
Don't implicitly unlock locked tables. Issue a implicit commit
at the end and unlock tables.
sql/sql_table.cc:
Close table and release metadata locks after a admin operation.
sql/table.h:
The problem is that the prepare phase of the CREATE TABLE
statement takes a exclusive metadata lock lock and this can
cause a self-deadlock the thread already holds a shared lock
on the table being that should be created.
The solution is to make the prepare phase take a shared
metadata lock when preparing a CREATE TABLE statement. The
execution of the statement will still acquire a exclusive
lock, but won't cause any problem as it issues a implicit
commit.
sql/transaction.cc:
Release metadata locks after the implicitly committed due
to a new transaction being started. Also, release metadata
locks acquired after a savepoint if the transaction is rolled
back to the save point.
The problem is that in some cases transaction-long metadata locks
could be released before the transaction was committed. This could
happen when a active transaction was ended by a "START TRANSACTION"
or "BEGIN" statement, in which case the metadata locks would be
released before the actual commit of the active transaction.
The solution is to defer the release of metadata locks to after the
transaction has been implicitly committed. No test case is provided
as the effort to provide one is too disproportional to the size of
the fix.
2617.31.12, 2617.31.15, 2617.31.15, 2617.31.16, 2617.43.1
- initial changeset that introduced the fix for
Bug#989 and follow up fixes for all test suite failures
introduced in the initial changeset.
------------------------------------------------------------
revno: 2617.31.1
committer: Davi Arnaut <Davi.Arnaut@Sun.COM>
branch nick: 4284-6.0
timestamp: Fri 2009-03-06 19:17:00 -0300
message:
Bug#989: If DROP TABLE while there's an active transaction, wrong binlog order
WL#4284: Transactional DDL locking
Currently the MySQL server does not keep metadata locks on
schema objects for the duration of a transaction, thus failing
to guarantee the integrity of the schema objects being used
during the transaction and to protect then from concurrent
DDL operations. This also poses a problem for replication as
a DDL operation might be replicated even thought there are
active transactions using the object being modified.
The solution is to defer the release of metadata locks until
a active transaction is either committed or rolled back. This
prevents other statements from modifying the table for the
entire duration of the transaction. This provides commitment
ordering for guaranteeing serializability across multiple
transactions.
- Incompatible change:
If MySQL's metadata locking system encounters a lock conflict,
the usual schema is to use the try and back-off technique to
avoid deadlocks -- this schema consists in releasing all locks
and trying to acquire them all in one go.
But in a transactional context this algorithm can't be utilized
as its not possible to release locks acquired during the course
of the transaction without breaking the transaction commitments.
To avoid deadlocks in this case, the ER_LOCK_DEADLOCK will be
returned if a lock conflict is encountered during a transaction.
Let's consider an example:
A transaction has two statements that modify table t1, then table
t2, and then commits. The first statement of the transaction will
acquire a shared metadata lock on table t1, and it will be kept
utill COMMIT to ensure serializability.
At the moment when the second statement attempts to acquire a
shared metadata lock on t2, a concurrent ALTER or DROP statement
might have locked t2 exclusively. The prescription of the current
locking protocol is that the acquirer of the shared lock backs off
-- gives up all his current locks and retries. This implies that
the entire multi-statement transaction has to be rolled back.
- Incompatible change:
FLUSH commands such as FLUSH PRIVILEGES and FLUSH TABLES WITH READ
LOCK won't cause locked tables to be implicitly unlocked anymore.
Fixed coredump in sql_plugin.cc:intern_plugin_lock() on mysqld start with PBXT
sql/mysqld.cc:
Fixed coredump in sql_plugin.cc:intern_plugin_lock() on mysqld start with PBXT
sql/share/errmsg.txt:
Row numbers are always positive
sql/sql_base.cc:
Fixed race condition in lock tables when killing insert_delayed thread.
This fixes Bug#47017 rpl_timezone fails on PB-2 with mismatch error
(Note that the patch only adds a continue; The rest is (required) indentation changes)
sql/sql_class.cc:
Fixed wrong output for high end machines in outfile_loaddata.
(Problem was that ER_TRUNCATED_WRONG_VALUE_FOR_FIELD expects ulong, not ulonglong)
sql/sql_insert.cc:
Ensure that if we get a lock problem with delayed_insert, the error is logged.
----------------------------------------------------------
revno: 2617.23.20
committer: Konstantin Osipov <kostja@sun.com>
branch nick: mysql-6.0-runtime
timestamp: Wed 2009-03-04 16:31:31 +0300
message:
WL#4284 "Transactional DDL locking"
Review comments: "Objectify" the MDL API.
MDL_request and MDL_context still need manual construction and
destruction, since they are used in environment that is averse
to constructors/destructors.
sql/mdl.cc:
Improve comments.
Add asserts to backup()/restore_from_backup()/merge() methods.
Fix an order bug in the error path of mdl_acquire_exclusive_locks():
we used to first free a ticket object, and only then exclude
it from the list of tickets.
----------------------------------------------------------
revno: 2617.23.20
committer: Konstantin Osipov <kostja@sun.com>
branch nick: mysql-6.0-runtime
timestamp: Wed 2009-03-04 16:31:31 +0300
message:
WL#4284 "Transactional DDL locking"
Review comments: "Objectify" the MDL API.
MDL_request and MDL_context still need manual construction and
destruction, since they are used in environment that is averse
to constructors/destructors.
revno: 2617.22.4
committer: Davi Arnaut <Davi.Arnaut@Sun.COM>
branch nick: mysql-6.0-runtime
timestamp: Mon 2009-01-26 15:19:14 -0200
message:
Move checks for OPTION_NOT_AUTOCOMMIT | OPTION_BEGIN to a separate
helper function.
sql/ha_ndbcluster.cc:
Use helper method to check transaction mode.
sql/log.cc:
Use helper method to check transaction mode.
sql/sql_cache.cc:
Use helper method to check transaction mode.
sql/sql_class.cc:
Use helper method to check transaction mode.
sql/sql_class.h:
Add helper method to check whether session is in a multi-statement
transaction.
sql/sql_parse.cc:
Use helper method to check transaction mode.
sql/transaction.cc:
Use helper method to check transaction mode.
-----------------------------------------------------------
2497.479.10 Sergei Golubchik 2008-08-27
proc_info_hook, mysys access to thd->proc_info
This patch is necessary for backport of WL#4284 "Transactional
DDL locking".
------------------------------------------------------------
revno: 2630.22.3
committer: Davi Arnaut <Davi.Arnaut@Sun.COM>
branch nick: 4284-6.0
timestamp: Thu 2008-08-07 22:33:43 -0300
message:
WL#4284: Transactional DDL locking
Make transaction management more modular through a new interface.
The overall objective of this change is to provide groundwork
for the design of transactional DDL locking by cleaning up the
transaction high level API to better distinguish operations implicit
and explicit, and single statement transaction from operations on
the normal transaction.
Having a a high-level interface for transaction management provides
a better base for implementing transactional concepts that are not
always tied to storage engines and also makes it easier to interect
with other higher level modules of the server.
client/Makefile.am:
Add new file to the build.
libmysqld/CMakeLists.txt:
Add new file to the build.
libmysqld/Makefile.am:
Add new file to the build.
sql/CMakeLists.txt:
Add new file to the build.
sql/Makefile.am:
Add new file to the build.
sql/handler.cc:
Remove multiplexer commit or rollback function. Most callers already
have enough information to decided whether to rollback or commit.
Having plain and well named functions makes it easier to read
and understand code.
sql/handler.h:
Remove wrapper function as the low level transaction functions
shouldn't be called directly anymore.
sql/log_event.cc:
Rename transaction management functions to the new names.
sql/log_event_old.cc:
Rename transaction management functions to the new names.
sql/mysql_priv.h:
Remove obsolete functions for implicit and explicit commit.
sql/rpl_injector.cc:
Rename transaction management functions to the new names.
sql/rpl_rli.cc:
Rename transaction management functions to the new names.
sql/set_var.cc:
Rename transaction management functions to the new names.
sql/slave.cc:
Rename transaction management functions to the new names.
sql/sql_base.cc:
Rename transaction management functions to the new names.
sql/sql_class.cc:
Rename transaction management functions to the new names.
sql/sql_delete.cc:
Rename transaction management functions to the new names.
sql/sql_do.cc:
Rename transaction management functions to the new names.
sql/sql_insert.cc:
Rename transaction management functions to the new names.
sql/sql_parse.cc:
Rename transaction management functions to the new names.
sql/sql_partition.cc:
Rename transaction management functions to the new names.
sql/sql_table.cc:
Rename transaction management functions to the new names.
sql/transaction.cc:
Implement wrapper functions to differentiate operations on
the single statement transaction from the ones operating
on the normal transaction.
sql/transaction.h:
Export new functions for dealing with transaction commands.
------------------------------------------------------------
revno: 2630.22.3
committer: Davi Arnaut <Davi.Arnaut@Sun.COM>
branch nick: 4284-6.0
timestamp: Thu 2008-08-07 22:33:43 -0300
message:
WL#4284: Transactional DDL locking
Make transaction management more modular through a new interface.
The overall objective of this change is to provide groundwork
for the design of transactional DDL locking by cleaning up the
transaction high level API to better distinguish operations implicit
and explicit, and single statement transaction from operations on
the normal transaction.
Having a a high-level interface for transaction management provides
a better base for implementing transactional concepts that are not
always tied to storage engines and also makes it easier to interect
with other higher level modules of the server.
------------------------------------------------------------
revno: 2630.4.39
committer: Dmitry Lenev <dlenev@mysql.com>
branch nick: mysql-6.0-3726-w2
timestamp: Thu 2008-06-26 13:08:27 +0400
message:
Fix warnings about passing pointer to not fully-initialized THD
object to constructor of base Open_tables_state classe, which
appeared on Windows and were introduced by one of the patches
implementing WL#3726 "DDL locking for all metadata objects".
sql/sql_class.cc:
Moved code preparing Open_tables_state instance for operations
which open/lock/close tables from class constructor to
init_open_tables_state() method. This allows us to move such
initialization of base Open_table_state instance in THD class
constructor from base classes initialization section to
constructor's body and thus to get rid of warnings about
about passing pointer to not fully-initialized THD object
to base class constructor.
sql/sql_class.h:
Moved code preparing Open_tables_state instance for operations
which open/lock/close tables from class constructor to
init_open_tables_state() method. This allows us to move such
initialization of base Open_table_state instance in THD class
constructor from base classes initialization section to
constructor's body and thus to get rid of warnings about
about passing pointer to not fully-initialized THD object
to base class constructor.
------------------------------------------------------------
revno: 2630.4.39
committer: Dmitry Lenev <dlenev@mysql.com>
branch nick: mysql-6.0-3726-w2
timestamp: Thu 2008-06-26 13:08:27 +0400
message:
Fix warnings about passing pointer to not fully-initialized THD
object to constructor of base Open_tables_state classe, which
appeared on Windows and were introduced by one of the patches
implementing WL#3726 "DDL locking for all metadata objects".
----------------------------------------------------------
revno: 2630.10.1
committer: Konstantin Osipov <konstantin@mysql.com>
branch nick: mysql-6.0-lock-tables-tidyup
timestamp: Wed 2008-06-11 15:49:58 +0400
message:
WL#3726, review fixes.
Now that we have metadata locks, we don't need to keep a crippled
TABLE instance in the table cache to indicate that a table is locked.
Remove all code that used this technique. Instead, rely on metadata
locks and use the standard open_table() and close_thread_table()
to manipulate with the table cache tables.
Removes a list of functions that have become unused (see the comment
for sql_base.cc for details).
Under LOCK TABLES, keep a TABLE_LIST instance for each table
that may be temporarily closed. For that, implement an own class for
LOCK TABLES mode, Locked_tables_list.
This is a pre-requisite patch for WL#4144.
This is not exactly a backport: there is no new
online ALTER table in Celosia, so the old alter table
code was changed to work with the new table cache API.
mysql-test/r/lock.result:
Update results (WL#3726 post-review patch).
mysql-test/r/trigger-compat.result:
We take the table from the table cache now, thus no warning.
mysql-test/suite/rpl/r/rpl_trigger.result:
We take the table from the table cache now, thus no warning.
mysql-test/t/lock.test:
Additional tests for LOCK TABLES mode (previously not covered by
the test suite (WL#3726).
sql/field.h:
Remove reopen_table().
sql/lock.cc:
Remove an obsolete parameter of mysql_lock_remove().
It's not used anywhere now either.
sql/mysql_priv.h:
Add 4 new open_table() flags.
Remove declarations of removed functions.
sql/sp_head.cc:
Rename thd->mdl_el_root to thd->locked_tables_root.
sql/sql_acl.cc:
Use the new implementation of unlock_locked_tables().
sql/sql_base.cc:
Implement class Locked_tables_list.
Implement close_all_tables_for_name().
Rewrite close_cached_tables() to use the new reopen_tables().
Remove reopen_table(), reopen_tables(), reopen_table_entry()
(ex. open_unireg_entry()), close_data_files_and_leave_as_placeholders(),
close_handle_and_leave_table_as_placeholder(), close_cached_table(),
table_def_change_share(), reattach_merge(), reopen_name_locked_table(),
unlink_open_table().
Move acquisition of a metadata lock into an own function
- open_table_get_mdl_lock().
sql/sql_class.cc:
Deploy class Locked_tables_list.
sql/sql_class.h:
Declare class Locked_tables_list.
Keep one instance of this class in class THD.
Rename mdl_el_root to locked_tables_root.
sql/sql_db.cc:
Update a comment.
sql/sql_insert.cc:
Use the plain open_table() to open a just created table in
CREATE TABLE .. SELECT.
sql/sql_parse.cc:
Use thd->locked_tables_list to enter and leave LTM_LOCK_TABLES mode.
sql/sql_partition.cc:
Deploy the new method of working with partitioned table locks.
sql/sql_servers.cc:
Update to the new signature of unlock_locked_tables().
sql/sql_table.cc:
In mysql_rm_table_part2(), the branch that removes a table under
LOCK TABLES, make sure that the table being dropped
is also removed from THD::locked_tables_list.
Update ALTER TABLE and CREATE TABLE LIKE implementation to use
open_table() and close_all_tables_for_name() instead of
reopen_tables().
sql/sql_trigger.cc:
Use the new locking way.
sql/table.h:
Add TABLE::pos_in_locked_tables, which is used only under
LOCK TABLES.
----------------------------------------------------------
revno: 2630.10.1
committer: Konstantin Osipov <konstantin@mysql.com>
branch nick: mysql-6.0-lock-tables-tidyup
timestamp: Wed 2008-06-11 15:49:58 +0400
message:
WL#3726, review fixes.
Now that we have metadata locks, we don't need to keep a crippled
TABLE instance in the table cache to indicate that a table is locked.
Remove all code that used this technique. Instead, rely on metadata
locks and use the standard open_table() and close_thread_table()
to manipulate with the table cache tables.
Removes a list of functions that have become unused (see the comment
for sql_base.cc for details).
Under LOCK TABLES, keep a TABLE_LIST instance for each table
that may be temporarily closed. For that, implement an own class for
LOCK TABLES mode, Locked_tables_list.
This is a pre-requisite patch for WL#4144.
This is not exactly a backport: there is no new
online ALTER table in Celosia, so the old alter table
code was changed to work with the new table cache API.
----------------------------------------------------------
revno: 2630.4.26
committer: Konstantin Osipov <konstantin@mysql.com>
branch nick: mysql-6.0-prelocked_mode-to-push
timestamp: Fri 2008-06-06 23:19:04 +0400
message:
WL#3726: work on review comments.
Remove thd->locked_tables. Always store MYSQL_LOCK instances in
thd->lock.
Rename thd->prelocked_mode to thd->locked_tables_mode.
Use thd->locked_tables_mode to determine if we
are under LOCK TABLES. Update the code to not assume that
if thd->lock is set, LOCK TABLES mode is off.
Review comments.
sql/ha_ndbcluster_binlog.cc:
Don't unlock the lock under LOCK TABLES (safety).
sql/handler.cc:
There is no thd->locked_tables any more.
Update comments.
sql/lock.cc:
There is no thd->locked_tables any more.
sql/log.cc:
Rename thd->prelocked_mode to thd->locked_tables_mode.
sql/set_var.cc:
Use thd->locked_tables_mode to determine if we are under LOCK TABLES.
sql/sp_head.cc:
Rename thd->prelocked_mode to thd->locked_tables_mode.
sql/sql_base.cc:
Use thd->locked_tables_mode to determine if we are under LOCK TABLES.
Remove thd->locked_tables.
sql/sql_cache.cc:
Use thd->locked_tables_mode to determine if we are under LOCK TABLES.
sql/sql_class.cc:
Avoid code duplication.
Do not release the table locks prematurely if we're under LOCK TABLES.
Use thd->locked_tables_mode instead of thd->locked_tables.
sql/sql_class.h:
Remove thd->locked_tables.
Make prelocked mode a kind of LOCK TABLES mode.
Update comments.
sql/sql_cursor.cc:
Update comments.
sql/sql_insert.cc:
Use thd->locked_tables_mode to determine if we are under LOCK TABLES.
Rename thd->prelocked_mode to thd->locked_tables_mode.
sql/sql_load.cc:
Rename thd->prelocked_mode to thd->locked_tables_mode.
sql/sql_parse.cc:
Use thd->locked_tables_mode to determine if we are under LOCK TABLES.
Remove thd->locked_tables.
sql/sql_partition.cc:
Use thd->locked_tables_mode to determine if we are under LOCK TABLES.
sql/sql_rename.cc:
Use thd->locked_tables_mode to determine if we are under LOCK TABLES.
sql/sql_select.cc:
Use thd->locked_tables_mode to determine if we are under LOCK TABLES.
sql/sql_table.cc:
Use thd->locked_tables_mode to determine if we are under LOCK TABLES.
sql/sql_trigger.cc:
Use thd->locked_tables_mode to determine if we are under LOCK TABLES.
sql/sql_update.cc:
Use thd->locked_tables_mode to determine if we are under LOCK TABLES.
sql/sql_view.cc:
Use thd->locked_tables_mode to determine if we are under LOCK TABLES.
storage/myisam/ha_myisam.cc:
Use thd->locked_tables_mode to determine if we are under LOCK TABLES.
----------------------------------------------------------
revno: 2630.4.26
committer: Konstantin Osipov <konstantin@mysql.com>
branch nick: mysql-6.0-prelocked_mode-to-push
timestamp: Fri 2008-06-06 23:19:04 +0400
message:
WL#3726: work on review comments.
Remove thd->locked_tables. Always store MYSQL_LOCK instances in
thd->lock.
Rename thd->prelocked_mode to thd->locked_tables_mode.
Use thd->locked_tables_mode to determine if we
are under LOCK TABLES. Update the code to not assume that
if thd->lock is set, LOCK TABLES mode is off.
Review comments.
