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- 17 Mar, 2010 1 commit
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Luis Soares authored
In BUG#49562 we fixed the case where numeric user var events would not serialize the flag stating whether the value was signed or unsigned (unsigned_flag). This fixed the case that the slave would get an overflow while treating the unsigned values as signed. In this bug, we find that the unsigned_flag can sometimes change between the moment that the user value is recorded for binlogging purposes and the actual binlogging time. Since we take the unsigned_flag from the runtime variable data, at binlogging time, and the variable value is comes from the copy taken earlier in the execution, there may be inconsistency in the User_var_log_event between the variable value and its unsigned_flag. We fix this by also copying the unsigned_flag of the user_var_entry when its value is copied, for binlogging purposes. Later, at binlogging time, we use the copied unsigned_flag and not the one in the runtime user_var_entry instance.
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- 13 Mar, 2010 1 commit
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Konstantin Osipov authored
Remove unnecessary need_reopen loops.
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- 03 Mar, 2010 1 commit
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Alexander Nozdrin authored
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- 24 Feb, 2010 1 commit
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Jon Olav Hauglid authored
This patch prevents system threads and system table accesses from using user-specified values for "lock_wait_timeout". Instead all such accesses are done using the default value (1 year). This prevents background tasks (such as replication, events, accessing stored function definitions, logging, reading time-zone information, etc.) from failing in cases where the global value of "lock_wait_timeout" is set very low. The patch also simplifies the open tables API. Rather than adding another convenience function for opening and locking system tables, this patch removes most of the existing convenience functions for open_and_lock_tables_derived(). Before, open_and_lock_tables() was a convenience function that enforced derived tables handling, while open_and_lock_tables_derived() was the main function where derived tables handling was optional. Now, this convencience function is gone and the main function is renamed to open_and_lock_tables(). No test case added as it would have required the use of --sleep to check that system threads and system tables have a different timeout value from the user-specified "lock_wait_timeout" system variable.
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- 22 Feb, 2010 1 commit
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Tatiana A. Nurnberg authored
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- 18 Feb, 2010 1 commit
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Tatiana A. Nurnberg authored
CHECK_FIELD_IGNORE was treated as CHECK_FIELD_ERROR_FOR_NULL; UPDATE...SET...NULL on NOT NULL fields behaved differently after a trigger. Now distinguishes between IGNORE and ERROR_FOR_NULL and save/restores check-field options.
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- 15 Feb, 2010 1 commit
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Alexander Nozdrin authored
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- 12 Feb, 2010 1 commit
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Dmitry Lenev authored
failed in enter_locked_tables_mode". Server was aborted due to assertion failure when one tried to execute statement requiring prelocking (i.e. firing triggers or using stored functions) while having open HANDLERs. The problem was that THD::enter_locked_tables_mode() method which was called at the beginning of execution of prelocked statement assumed there are no open HANDLERs. It had to do so because corresponding THD::leave_locked_tables_mode() method was unable to properly restore MDL sentinel when leaving LOCK TABLES/prelocked mode in the presence of open HANDLERs. This patch solves this problem by changing the latter method to properly restore MDL sentinel and thus removing need for this assumption. As a side-effect, it lifts unjustified limitation by allowing to keep HANDLERs open when entering LOCK TABLES mode.
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- 11 Feb, 2010 1 commit
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Jon Olav Hauglid authored
This patch introduces timeouts for metadata locks. The timeout is specified in seconds using the new dynamic system variable "lock_wait_timeout" which has both GLOBAL and SESSION scopes. Allowed values range from 1 to 31536000 seconds (= 1 year). The default value is 1 year. The new server parameter "lock-wait-timeout" can be used to set the default value parameter upon server startup. "lock_wait_timeout" applies to all statements that use metadata locks. These include DML and DDL operations on tables, views, stored procedures and stored functions. They also include LOCK TABLES, FLUSH TABLES WITH READ LOCK and HANDLER statements. The patch also changes thr_lock.c code (table data locks used by MyISAM and other simplistic engines) to use the same system variable. InnoDB row locks are unaffected. One exception to the handling of the "lock_wait_timeout" variable is delayed inserts. All delayed inserts are executed with a timeout of 1 year regardless of the setting for the global variable. As the connection issuing the delayed insert gets no notification of delayed insert timeouts, we want to avoid unnecessary timeouts. It's important to note that the timeout value is used for each lock acquired and that one statement can take more than one lock. A statement can therefore block for longer than the lock_wait_timeout value before reporting a timeout error. When lock timeout occurs, ER_LOCK_WAIT_TIMEOUT is reported. Test case added to lock_multi.test.
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- 09 Feb, 2010 1 commit
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Luis Soares authored
As part of BUG@39934 fix, the public: - THD::current_stmt_binlog_row_based variable had been removed and replaced by a private variable: - THD::current_stmt_binlog_format. THD was refactored and some modifiers and accessors were implemented for the new variable. However, due to a bad merge, the THD::current_stmt_binlog_row_based variable is back as a public member of THD. This in itself is already potentially harmful. What's even worse is that while merging some more patches and resolving conflicts, the variable started being used again, which is obviously wrong. To fix this we: 1. remove the extraneous variable from sql_class.h 2. revert a bad merge for BUG#49132 3. merge BUG#49132 properly again (actually, making use of the cset used to merge the original patch to mysql-pe).
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- 04 Feb, 2010 1 commit
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Konstantin Osipov authored
Cherry-pick a fix Bug#37148 from next-mr, to preserve file ids of the added files, and ensure that all the necessary changes have been pulled. Since initially Bug#37148 was null-merged into 6.0, the changeset that is now being cherry-picked was likewise null merged into next-4284. Now that Bug#37148 has been reapplied to 6.0, try to make it work with next-4284. This is also necessary to be able to pull other changes from 5.1-rep into next-4284. To resolve the merge issues use this changeset applied to 6.0: revid:jperkin@sun.com-20091216103628-ylhqf7s6yegui2t9 revno: 3776.1.1 committer: He Zhenxing <zhenxing.he@sun.com> branch nick: 6.0-codebase-bugfixing timestamp: Thu 2009-12-17 17:02:50 +0800 message: Fix merge problem with Bug#37148
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- 03 Feb, 2010 1 commit
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MySQL Build Team authored
> ------------------------------------------------------------ > revno: 2818.1.40 [merge] > revision-id: epotemkin@mysql.com-20091202134712-4muwnr152xqkcwm7 > parent: gshchepa@mysql.com-20091201102444-yw166t3audrojo9s > parent: epotemkin@mysql.com-20091201182845-aw0uawt6c6gwi98c > committer: Evgeny Potemkin <epotemkin@mysql.com> > branch nick: mysql-5.0-bugteam > timestamp: Wed 2009-12-02 16:47:12 +0300 > message: > Auto-merged fix for the bug#48508. > ------------------------------------------------------------ > Use --include-merges or -n0 to see merged revisions.
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- 01 Feb, 2010 1 commit
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Dmitry Lenev authored
Add a wait-for graph based deadlock detector to the MDL subsystem. Fixes bug #46272 "MySQL 5.4.4, new MDL: unnecessary deadlock" and bug #37346 "innodb does not detect deadlock between update and alter table". The first bug manifested itself as an unwarranted abort of a transaction with ER_LOCK_DEADLOCK error by a concurrent ALTER statement, when this transaction tried to repeat use of a table, which it has already used in a similar fashion before ALTER started. The second bug showed up as a deadlock between table-level locks and InnoDB row locks, which was "detected" only after innodb_lock_wait_timeout timeout. A transaction would start using the table and modify a few rows. Then ALTER TABLE would come in, and start copying rows into a temporary table. Eventually it would stumble on the modified records and get blocked on a row lock. The first transaction would try to do more updates, and get blocked on thr_lock.c lock. This situation of circular wait would only get resolved by a timeout. Both these bugs stemmed from inadequate solutions to the problem of deadlocks occurring between different locking subsystems. In the first case we tried to avoid deadlocks between metadata locking and table-level locking subsystems, when upgrading shared metadata lock to exclusive one. Transactions holding the shared lock on the table and waiting for some table-level lock used to be aborted too aggressively. We also allowed ALTER TABLE to start in presence of transactions that modify the subject table. ALTER TABLE acquires TL_WRITE_ALLOW_READ lock at start, and that block all writes against the table (naturally, we don't want any writes to be lost when switching the old and the new table). TL_WRITE_ALLOW_READ lock, in turn, would block the started transaction on thr_lock.c lock, should they do more updates. This, again, lead to the need to abort such transactions. The second bug occurred simply because we didn't have any mechanism to detect deadlocks between the table-level locks in thr_lock.c and row-level locks in InnoDB, other than innodb_lock_wait_timeout. This patch solves both these problems by moving lock conflicts which are causing these deadlocks into the metadata locking subsystem, thus making it possible to avoid or detect such deadlocks inside MDL. To do this we introduce new type-of-operation-aware metadata locks, which allow MDL subsystem to know not only the fact that transaction has used or is going to use some object but also what kind of operation it has carried out or going to carry out on the object. This, along with the addition of a special kind of upgradable metadata lock, allows ALTER TABLE to wait until all transactions which has updated the table to go away. This solves the second issue. Another special type of upgradable metadata lock is acquired by LOCK TABLE WRITE. This second lock type allows to solve the first issue, since abortion of table-level locks in event of DDL under LOCK TABLES becomes also unnecessary. Below follows the list of incompatible changes introduced by this patch: - From now on, ALTER TABLE and CREATE/DROP TRIGGER SQL (i.e. those statements that acquire TL_WRITE_ALLOW_READ lock) wait for all transactions which has *updated* the table to complete. - From now on, LOCK TABLES ... WRITE, REPAIR/OPTIMIZE TABLE (i.e. all statements which acquire TL_WRITE table-level lock) wait for all transaction which *updated or read* from the table to complete. As a consequence, innodb_table_locks=0 option no longer applies to LOCK TABLES ... WRITE. - DROP DATABASE, DROP TABLE, RENAME TABLE no longer abort statements or transactions which use tables being dropped or renamed, and instead wait for these transactions to complete. - Since LOCK TABLES WRITE now takes a special metadata lock, not compatible with with reads or writes against the subject table and transaction-wide, thr_lock.c deadlock avoidance algorithm that used to ensure absence of deadlocks between LOCK TABLES WRITE and other statements is no longer sufficient, even for MyISAM. The wait-for graph based deadlock detector of MDL subsystem may sometimes be necessary and is involved. This may lead to ER_LOCK_DEADLOCK error produced for multi-statement transactions even if these only use MyISAM: session 1: session 2: begin; update t1 ... lock table t2 write, t1 write; -- gets a lock on t2, blocks on t1 update t2 ... (ER_LOCK_DEADLOCK) - Finally, support of LOW_PRIORITY option for LOCK TABLES ... WRITE was abandoned. LOCK TABLE ... LOW_PRIORITY WRITE from now on has the same priority as the usual LOCK TABLE ... WRITE. SELECT HIGH PRIORITY no longer trumps LOCK TABLE ... WRITE in the wait queue. - We do not take upgradable metadata locks on implicitly locked tables. So if one has, say, a view v1 that uses table t1, and issues: LOCK TABLE v1 WRITE; FLUSH TABLE t1; -- (or just 'FLUSH TABLES'), an error is produced. In order to be able to perform DDL on a table under LOCK TABLES, the table must be locked explicitly in the LOCK TABLES list.
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- 10 Feb, 2010 1 commit
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Martin Hansson authored
error causes debug assertion The IGNORE option of the multiple-table UPDATE command was not intended to suppress errors caused by the sql_safe_updates mode. This flag will raise an error if the execution of UPDATE does not use a key for row retrieval, and should continue do so regardless of the IGNORE option. However the implementation of IGNORE does not support exceptions to the rule; it always converts errors to warnings and cannot be extended. The Internal_error_handler interface offers the infrastructure to handle individual errors, making sure that the error raised by sql_safe_updates is not silenced. Fixed by implementing an Internal_error_handler and using it for UPDATE IGNORE commands.
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- 24 Jan, 2010 1 commit
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He Zhenxing authored
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- 21 Jan, 2010 2 commits
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Dmitry Lenev authored
condition variable per context instead of one mutex and one conditional variable for the whole subsystem. This should increase concurrency in this subsystem. It also opens the way for further changes which are necessary to solve such bugs as bug #46272 "MySQL 5.4.4, new MDL: unnecessary deadlock" and bug #37346 "innodb does not detect deadlock between update and alter table". Two other notable changes done by this patch: - MDL subsystem no longer implicitly acquires global intention exclusive metadata lock when per-object metadata lock is acquired. Now this has to be done by explicit calls outside of MDL subsystem. - Instead of using separate MDL_context for opening system tables/tables for purposes of I_S we now create MDL savepoint in the main context before opening tables and rollback to this savepoint after closing them. This means that it is now possible to get ER_LOCK_DEADLOCK error even not inside a transaction. This might happen in unlikely case when one runs DDL on one of system tables while also running DDL on some other tables. Cases when this ER_LOCK_DEADLOCK error is not justified will be addressed by advanced deadlock detector for MDL subsystem which we plan to implement.
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Alfranio Correia authored
It is well-known that due to concurrency issues, a slave can become inconsistent when a transaction contains updates to both transaction and non-transactional tables. In a nutshell, the current code-base tries to preserve causality among the statements by writing non-transactional statements to the txn-cache which is flushed upon commit. However, modifications done to non-transactional tables on behalf of a transaction become immediately visible to other connections but may not immediately get into the binary log and therefore consistency may be broken. In general, it is impossible to automatically detect causality/dependency among statements by just analyzing the statements sent to the server. This happen because dependency may be hidden in the application code and it is necessary to know a priori all the statements processed in the context of a transaction such as in a procedure. Moreover, even for the few cases that we could automatically address in the server, the computation effort required could make the approach infeasible. So, in this patch we introduce the option - "--binlog-direct-non-transactional-updates" that can be used to bypass the current behavior in order to write directly to binary log statements that change non-transactional tables. Besides, it is used to enable the WL#2687 which is disabled by default.
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- 20 Jan, 2010 1 commit
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Alfranio Correia authored
It is well-known that due to concurrency issues, a slave can become inconsistent when a transaction contains updates to both transaction and non-transactional tables in statement and mixed modes. In a nutshell, the current code-base tries to preserve causality among the statements by writing non-transactional statements to the txn-cache which is flushed upon commit. However, modifications done to non-transactional tables on behalf of a transaction become immediately visible to other connections but may not immediately get into the binary log and therefore consistency may be broken. In general, it is impossible to automatically detect causality/dependency among statements by just analyzing the statements sent to the server. This happen because dependency may be hidden in the application code and it is necessary to know a priori all the statements processed in the context of a transaction such as in a procedure. Moreover, even for the few cases that we could automatically address in the server, the computation effort required could make the approach infeasible. So, in this patch we introduce the option - "--binlog-direct-non-transactional-updates" that can be used to bypass the current behavior in order to write directly to binary log statements that change non-transactional tables.
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- 07 Jan, 2010 1 commit
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Marc Alff authored
Part IV: sql instrumentation
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- 30 Dec, 2009 1 commit
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Dmitry Lenev authored
This change is supposed to reduce number of ER_LOCK_DEADLOCK errors which occur when multi-statement transaction encounters conflicting metadata lock in cases when waiting is possible. The idea is not to fail ER_LOCK_DEADLOCK error immediately when we encounter conflicting metadata lock. Instead we release all metadata locks acquired by current statement and start to wait until conflicting lock go away. To avoid deadlocks we use simple empiric which aborts waiting with ER_LOCK_DEADLOCK error if it turns out that somebody is waiting for metadata locks owned by this transaction. This patch also fixes bug #46273 "MySQL 5.4.4 new MDL: Bug#989 is not fully fixed in case of ALTER". The bug was that concurrent execution of UPDATE or MULTI-UPDATE statement as a part of multi-statement transaction that already has used table being updated and ALTER TABLE statement might have resulted of loss of isolation between this transaction and ALTER TABLE statement, which manifested itself as changes performed by ALTER TABLE becoming visible in transaction and wrong binary log order as a consequence. This problem occurred when UPDATE or MULTI-UPDATE's wait in mysql_lock_tables() call was aborted due to metadata lock upgrade performed by concurrent ALTER TABLE. After such abort all metadata locks held by transaction were released but transaction silently continued to be executed as if nothing has happened. We solve this problem by changing our code not to release all locks in such case. Instead we release only locks which were acquired by current statement and then try to reacquire them by restarting open/lock tables process. We piggyback on simple deadlock detector implementation since this change has to be done anyway for it.
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- 29 Dec, 2009 1 commit
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Konstantin Osipov authored
3655 Jon Olav Hauglid 2009-10-19 Bug #30977 Concurrent statement using stored function and DROP FUNCTION breaks SBR Bug #48246 assert in close_thread_table Implement a fix for: Bug #41804 purge stored procedure cache causes mysterious hang for many minutes Bug #49972 Crash in prepared statements The problem was that concurrent execution of DML statements that use stored functions and DDL statements that drop/modify the same function might result in incorrect binary log in statement (and mixed) mode and therefore break replication. This patch fixes the problem by introducing metadata locking for stored procedures and functions. This is similar to what is done in Bug#25144 for views. Procedures and functions now are locked using metadata locks until the transaction is either committed or rolled back. This prevents other statements from modifying the procedure/function while it is being executed. This provides commit ordering - guaranteeing serializability across multiple transactions and thus fixes the reported binlog problem. Note that we do not take locks for top-level CALLs. This means that procedures called directly are not protected from changes by simultaneous DDL operations so they are executed at the state they had at the time of the CALL. By not taking locks for top-level CALLs, we still allow transactions to be started inside procedures. This patch also changes stored procedure cache invalidation. Upon a change of cache version, we no longer invalidate the entire cache, but only those routines which we use, only when a statement is executed that uses them. This patch also changes the logic of prepared statement validation. A stored procedure used by a prepared statement is now validated only once a metadata lock has been acquired. A version mismatch causes a flush of the obsolete routine from the cache and statement reprepare. Incompatible changes: 1) ER_LOCK_DEADLOCK is reported for a transaction trying to access a procedure/function that is locked by a DDL operation in another connection. 2) Procedure/function DDL operations are now prohibited in LOCK TABLES mode as exclusive locks must be taken all at once and LOCK TABLES provides no way to specifiy procedures/functions to be locked. Test cases have been added to sp-lock.test and rpl_sp.test. Work on this bug has very much been a team effort and this patch includes and is based on contributions from Davi Arnaut, Dmitry Lenev, Magne Mæhre and Konstantin Osipov.
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- 22 Dec, 2009 2 commits
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Konstantin Osipov authored
"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.
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Sergei Golubchik authored
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
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- 15 Dec, 2009 1 commit
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Sergey Vojtovich authored
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.
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- 14 Dec, 2009 1 commit
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Mats Kindahl authored
Row-based replication requires the types of columns on the master and slave to be approximately the same (some safe conversions between strings are allowed), but does not allow safe conversions between fields of similar types such as TINYINT and INT. This patch implement type conversions between similar fields on the master and slave. The conversions are controlled using a new variable SLAVE_TYPE_CONVERSIONS of type SET('ALL_LOSSY','ALL_NON_LOSSY'). Non-lossy conversions are any conversions that do not run the risk of losing any information, while lossy conversions can potentially truncate the value. The column definitions are checked to decide if the conversion is acceptable. If neither conversion is enabled, it is required that the definitions of the columns are identical on master and slave. Conversion is done by creating an internal conversion table, unpacking the master data into it, and then copy the data to the real table on the slave.
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- 10 Dec, 2009 2 commits
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Jon Olav Hauglid authored
Bug #48210 FLUSH TABLES WITH READ LOCK deadlocks against concurrent CREATE PROCEDURE This deadlock occured between a) CREATE PROCEDURE (or other commands listed below) b) FLUSH TABLES WITH READ LOCK If the execution of them happened in the following order: - a) opens a table (e.g. mysql.proc) - b) locks the global read lock (or GRL) - a) sleeps inside wait_if_global_read_lock() - b) increases refresh_version and sleeps waiting for old tables to go away Note that a) must start waiting on the GRL before FLUSH increases refresh_version. Otherwise a) won't wait on the GRL and instead close its tables for reopen, allowing FLUSH to complete and thus avoid the deadlock. With this patch the deadlock is avoided by making CREATE PROCEDURE acquire a protection against global read locks before it starts executing. This means that FLUSH TABLES WITH READ LOCK will have to wait until CREATE PROCEDURE completes before acquiring the global read lock, thereby avoiding the deadlock. This is implemented by introducing a new SQL command flag called CF_PROTECT_AGAINST_GRL. Commands marked with this flag will acquire a GRL protection in the beginning of mysql_execute_command(). This patch adds the flag to CREATE, ALTER and DROP for PROCEDURE and FUNCTION, as well as CREATE USER, DROP USER, RENAME USER and REVOKE ALL. All these commands either call open_grant_tables() or open_system_table_for_updated() which make them susceptible for this deadlock. The patch also adds the CF_PROTECT_AGAINST_GRL flag to a number of commands that previously acquired GRL protection in their respective SQLCOM case in mysql_execute_command(). Test case that checks for GRL protection for CREATE PROCEDURE and CREATE USER added to mdl_sync.test.
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Marc Alff authored
Part III: mysys instrumentation
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- 09 Dec, 2009 1 commit
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Jon Olav Hauglid authored
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.
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- 08 Dec, 2009 4 commits
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Jon Olav Hauglid authored
Bug #45067 Assertion `stmt_da->is_error()' in Delayed_insert::open_and_lock_table The assert was triggered when delayed insert was killed by another connection using mysql_notify_thread_having_shared_lock(). During handling of thd->killed, thd.fatal_error() was called without a previous call to my_error() which triggered the assert. This patch allows the assert to pass if thd->killed has been set.
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Konstantin Osipov authored
---------------------------------------------------------- revno: 2617.69.24 committer: Konstantin Osipov <kostja@sun.com> branch nick: 5.4-42546 timestamp: Fri 2009-08-14 19:22:05 +0400 message: A pre-requisite for a fix for Bug#42546 "Backup: RESTORE fails, thinking it finds an existing table" Back-port from WL 148 "Foreign keys" feature tree a patch that introduced Prelocking_strategy class -- a way to parameterize open_tables() behaviour, implemented by Dmitry Lenev. (Part of WL#4284).
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Konstantin Osipov authored
---------------------------------------------------------- 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.
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Konstantin Osipov authored
---------------------------------------------------------- revno: 2617.69.2 committer: Konstantin Osipov <kostja@sun.com> branch nick: 5.4-azalea-bugfixing timestamp: Mon 2009-08-03 19:26:04 +0400 message: A fix and a test case for Bug#45035 "Altering table under LOCK TABLES results in "Error 1213 Deadlock found...". If a user had a table locked with LOCK TABLES for READ and for WRITE in the same connection, ALTER TABLE could fail. Root cause analysis: If a connection issues LOCK TABLE t1 write, t1 a read, t1 b read; the new LOCK TABLES code in 6.0 (part of WL 3726) will create the following list of TABLE_LIST objects (thd->locked_tables_list->m_locked_tables): {"t1" "b" tl_read_no_insert}, {"t1" "a" tl_read_no_insert}, {"t1" "t1" tl_write } Later on, when we try to ALTER table t1, mysql_alter_table() closes all TABLE instances and releases its thr_lock locks, keeping only an exclusive metadata lock on t1. But when ALTER is finished, Locked_table_list::reopen_tables() tries to restore the original list of open and locked tables. Before this patch, it used to do so one by one: Open t1 b, get TL_READ_NO_INSERT lock, Open t1 a, get TL_READ_NO_INSERT lock Open t1, try to get TL_WRITE lock, deadlock. The cause of the deadlock is that thr_lock.c doesn't resolve the situation when the read list only consists of locks taken by the same thread, followed by this very thread trying to take a WRITE lock. Indeed, since thr_lock_multi always gets a sorted list of locks, WRITE locks always precede READ locks in the list to lock. Don't try to fix thr_lock.c deficiency, keep this code simple. Instead, try to take all thr_lock locks at once in ::reopen_tables().
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- 05 Dec, 2009 1 commit
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Marc Alff authored
Part II, engines instrumentation
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- 03 Dec, 2009 5 commits
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Konstantin Osipov authored
---------------------------------------------------------- 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.
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Konstantin Osipov authored
------------------------------------------------------------ revno: 2617.23.18 committer: Davi Arnaut <Davi.Arnaut@Sun.COM> branch nick: 4284-6.0 timestamp: Mon 2009-03-02 18:18:26 -0300 message: Bug#989: If DROP TABLE while there's an active transaction, wrong binlog order WL#4284: Transactional DDL locking This is a prerequisite patch: These changes are intended to split lock requests from granted locks and to allow the memory and lifetime of granted locks to be managed within the MDL subsystem. Furthermore, tickets can now be shared and therefore are used to satisfy multiple lock requests, but only shared locks can be recursive. The problem is that the MDL subsystem morphs lock requests into granted locks locks but does not manage the memory and lifetime of lock requests, and hence, does not manage the memory of granted locks either. This can be problematic because it puts the burden of tracking references on the users of the subsystem and it can't be easily done in transactional contexts where the locks have to be kept around for the duration of a transaction. Another issue is that recursive locks (when the context trying to acquire a lock already holds a lock on the same object) requires that each time the lock is granted, a unique lock request/granted lock structure structure must be kept around until the lock is released. This can lead to memory leaks in transactional contexts as locks taken during the transaction should only be released at the end of the transaction. This also leads to unnecessary wake ups (broadcasts) in the MDL subsystem if the context still holds a equivalent of the lock being released. These issues are exacerbated due to the fact that WL#4284 low-level design says that the implementation should "2) Store metadata locks in transaction memory root, rather than statement memory root" but this is not possible because a memory root, as implemented in mysys, requires all objects allocated from it to be freed all at once. This patch combines review input and significant code contributions from Konstantin Osipov (kostja) and Dmitri Lenev (dlenev).
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Konstantin Osipov authored
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.
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Konstantin Osipov authored
------------------------------------------------------------ revno: 2630.13.16 committer: Davi Arnaut <Davi.Arnaut@Sun.COM> branch nick: WL#4284 timestamp: Sat 2008-07-26 13:38:20 -0300 message: WL#4284: Transactional DDL locking SQL statements' effect on transactions. Currently the MySQL server and its storage engines are not capable of rolling back operations that define or modify data structures (also known as DDL statements) or operations that alter any of the system tables (the mysql database). Allowing these group of statements to participate in transactions is unfeasible at this time (since rollback has no effect whatsoever on them) and goes against the design of our metadata locking subsystem. The solution is to issue implicit commits before and after those statements execution. This effectively confines each of those statements to its own special transaction and ensures that metadata locks taken during this special transaction are not leaked into posterior statements/transactions.
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Konstantin Osipov authored
------------------------------------------------------------ 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".
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- 02 Dec, 2009 1 commit
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Konstantin Osipov authored
---------------------------------------------------------- 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.
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- 01 Dec, 2009 1 commit
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Evgeny Potemkin authored
Actually there is two different bugs. The first one caused crash on queries with WHERE condition over views containing WHERE condition. A wrong check for prepared statement phase led to items for view fields being allocated in the execution memory and freed at the end of execution. Thus the optimized WHERE condition refers to unallocated memory on the second execution and server crashed. The second one caused by the Item_cond::compile function not saving changes it made to the item tree. Thus on the next execution changes weren't reverted and server crashed on dereferencing of unallocated space. The new helper function called is_stmt_prepare_or_first_stmt_execute is added to the Query_arena class. The find_field_in_view function now uses is_stmt_prepare_or_first_stmt_execute() to check whether newly created view items should be freed at the end of the query execution. The Item_cond::compile function now saves changes it makes to item tree.
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