Commit graph

1080 commits

Author SHA1 Message Date
Sergei Golubchik
69e076ec78 bugfix: delay_key_write=ALL cannot be turned off 2011-10-19 22:51:24 +02:00
Sergei Golubchik
76f0b94bb0 merge with 5.3
sql/sql_insert.cc:
  CREATE ... IF NOT EXISTS may do nothing, but
  it is still not a failure. don't forget to my_ok it.
  ******
  CREATE ... IF NOT EXISTS may do nothing, but
  it is still not a failure. don't forget to my_ok it.
sql/sql_table.cc:
  small cleanup
  ******
  small cleanup
2011-10-19 21:45:18 +02:00
Sergei Golubchik
2005689700 sys_vars changes and cleanups 2011-07-11 20:33:39 +02:00
Sergei Golubchik
b4a0b2c2f8 post-merge fixes.
most tests pass.
5.3 merge is next
2011-07-02 22:12:12 +02:00
Sergei Golubchik
9809f05199 5.5-merge 2011-07-02 22:08:51 +02:00
Guilhem Bichot
3ceec2f19c Merge from 5.1. 2011-05-21 10:21:08 +02:00
Kent Boortz
02e07e3b51 Updated/added copyright headers 2011-06-30 17:46:53 +02:00
Kent Boortz
9da00ebec9 Updated/added copyright headers 2011-06-30 17:46:53 +02:00
Guilhem Bichot
12f651ac9d Merge from 5.1. 2011-05-21 10:21:08 +02:00
Sergei Golubchik
0accbd0364 lots of post-merge changes 2011-04-25 17:22:25 +02:00
Georgi Kodinov
0d01bcca9d Merged bug #11766769 to 5.5.
Added back the specific warning number.
2011-03-25 14:55:22 +02:00
Georgi Kodinov
1e1ebd7a57 Merged bug #11766769 to 5.5.
Added back the specific warning number.
2011-03-25 14:55:22 +02:00
Georgi Kodinov
54461b0699 Bug #11766306: 59393: have_innodb=yes when mysqld started with --skip-innodb
Initialized correctly the have_innodb variable so that when the plugin is not initialized it
stays "disabled" instead of "yes".
Test suite added.
2011-03-23 19:03:42 +02:00
Georgi Kodinov
9c232a2c82 Bug #11766306: 59393: have_innodb=yes when mysqld started with --skip-innodb
Initialized correctly the have_innodb variable so that when the plugin is not initialized it
stays "disabled" instead of "yes".
Test suite added.
2011-03-23 19:03:42 +02:00
Dmitry Shulga
feb6d22328 Manual merge from mysql-5.1 for Bug#11764168 (56976: Severe denial
of service in prepared statements).

sql/sql_prepare.cc:
  At mysql_stmt_get_longdata(): instead of pushing an internal
  error handler (as done in 5.1-tree) we save, set and restore
  the statement's diagnostics area and warning info.
2011-03-15 18:57:36 +06:00
Dmitry Shulga
10f5982ee5 Manual merge from mysql-5.1 for Bug#11764168 (56976: Severe denial
of service in prepared statements).
2011-03-15 18:57:36 +06:00
Magne Mahre
5a47bc87c8 Merge from 5.1 2011-02-17 12:53:09 +01:00
Magne Mahre
2a3456597b Merge from 5.1 2011-02-17 12:53:09 +01:00
Georgi Kodinov
fe145b0900 merge 2011-02-02 20:13:28 +02:00
Georgi Kodinov
3b65062d33 merge 2011-02-02 20:13:28 +02:00
Ramil Kalimullin
7e4961bd51 Fix for bug #58669: read_only not enforced on 5.5.x
merged from mysql-5.5.8-release tree,
revision: ramil@mysql.com-20101203174908-217tdkn150vieha9
2010-12-07 20:08:54 +03:00
Ramil Kalimullin
d33574fbf7 Fix for bug #58669: read_only not enforced on 5.5.x
merged from mysql-5.5.8-release tree,
revision: ramil@mysql.com-20101203174908-217tdkn150vieha9
2010-12-07 20:08:54 +03:00
Sergei Golubchik
37f87d73ae updated sys_vars.cc (converting 5.3 mysqld.cc and set_var.cc
changes appropriately)
2010-11-26 12:22:40 +01:00
Sergei Golubchik
65ca700def merge.
checkpoint.
does not compile.
2010-11-25 18:17:28 +01:00
Alfranio Correia
3f5a9c7ea0 BUG#57275 binlog_cache_size affects trx- and stmt-cache and gets twice the expected memory
After the WL#2687, the binlog_cache_size and max_binlog_cache_size affect both the
stmt-cache and the trx-cache. This means that the resource used is twice the amount
expected/defined by the user.
      
The binlog_cache_use is incremented when the stmt-cache or the trx-cache is used
and binlog_cache_disk_use is incremented when the disk space from the stmt-cache or the
trx-cache is used. This behavior does not allow to distinguish which cache may be harming
performance due to the extra disk accesses and needs to have its in-memory cache
increased.
      
To fix the problem, we introduced two new options and status variables related to the
stmt-cache:
      
  Options:
      
    . binlog_stmt_cache_size
    . max_binlog_stmt_cache_size
      
    Status Variables:
      
    . binlog_stmt_cache_use
    . binlog_stmt_cache_disk_use

So there are

  . binlog_cache_size that defines the size of the transactional cache for
  updates to transactional engines for the binary log.

  . binlog_stmt_cache_size that defines the size of the statement cache for
  updates to non-transactional engines for the binary log.

  . max_binlog_cache_size that sets the total size of the transactional
  cache.

  . max_binlog_stmt_cache_size that sets the total size of the statement
  cache.

  . binlog_cache_use that identifies the number of transactions that used the
  temporary transactional binary log cache.

  . binlog_cache_disk_use that identifies the number of transactions that used
  the temporary transactional binary log cache but that exceeded the value of
  binlog_cache_size.

  . binlog_stmt_cache_use that identifies the number of statements that used the
  temporary non-transactional binary log cache.

  . binlog_stmt_cache_disk_use that identifies the number of statements that used
  the temporary non-transactional binary log cache but that exceeded the value of
  binlog_stmt_cache_size.

include/my_sys.h:
  Updated message on disk_writes' usage.
mysql-test/extra/binlog_tests/binlog_cache_stat.test:
  Updated the test case and added code to check the new status variables
  binlog_stmt_cache_use and binlog_stmt_cache_disk_use.
mysql-test/extra/rpl_tests/rpl_binlog_max_cache_size.test:
  Updated the test case to use the new system variables max_binlog_stmt_cache_size and binlog_stmt_cache_size.
mysql-test/r/mysqld--help-notwin.result:
  Updated the result file.
mysql-test/suite/binlog/r/binlog_mixed_cache_stat.result:
  Updated the result file.
mysql-test/suite/binlog/r/binlog_row_cache_stat.result:
  Updated the result file.
mysql-test/suite/binlog/r/binlog_stm_cache_stat.result:
  Updated the result file.
mysql-test/suite/rpl/r/rpl_mixed_binlog_max_cache_size.result:
  Update the result file.
mysql-test/suite/rpl/r/rpl_row_binlog_max_cache_size.result:
  Update the result file.
mysql-test/suite/rpl/r/rpl_stm_binlog_max_cache_size.result:
  Updated the result file.
mysql-test/suite/sys_vars/inc/binlog_stmt_cache_size_basic.inc:
  Added a test case to check the binlog_stmt_cache_size.
mysql-test/suite/sys_vars/r/binlog_stmt_cache_size_basic_32.result:
  Updated the result file.
mysql-test/suite/sys_vars/r/binlog_stmt_cache_size_basic_64.result:
  Updated the result file.
mysql-test/suite/sys_vars/r/max_binlog_stmt_cache_size_basic.result:
  Updated the result file.
mysql-test/suite/sys_vars/t/binlog_stmt_cache_size_basic_32.test:
  Added a test case to check the binlog_stmt_cache_size.
mysql-test/suite/sys_vars/t/binlog_stmt_cache_size_basic_64.test:
  Added a test case to check the binlog_stmt_cache_size.
mysql-test/suite/sys_vars/t/max_binlog_cache_size_func-master.opt:
  Removed because there is no test case max_binlog_cache_size_func.
mysql-test/suite/sys_vars/t/max_binlog_stmt_cache_size_basic.test:
  Added a test case to check the system variable max_binlog_stmt_cache_size.
sql/log.cc:
  There two main changes in here:
  
    . Changed the set_write_error() as an error message is set according
    to the type of the cache.
  
    . Created the function set_binlog_cache_info where references to the
    appropriate status and system variables are set and the server can
    smoothly compute statistics and set the maximum size for each cache.
sql/log.h:
  Changed the signature of the function in order to identify the error message
  to be printed out as there is a different error code for each type of cache.
sql/mysqld.cc:
  Added new status variables binlog_stmt_cache_use and binlog_stmt_cache_disk_use.
sql/mysqld.h:
  Added new system variables max_binlog_stmt_cache_size and binlog_stmt_cache_size.
sql/share/errmsg-utf8.txt:
  Added new error message related to the statement cache.
sql/sys_vars.cc:
  Added new system variables max_binlog_stmt_cache_size and binlog_stmt_cache_size.
2010-11-05 17:42:37 +00:00
Alfranio Correia
bf2c66d4a7 BUG#57275 binlog_cache_size affects trx- and stmt-cache and gets twice the expected memory
After the WL#2687, the binlog_cache_size and max_binlog_cache_size affect both the
stmt-cache and the trx-cache. This means that the resource used is twice the amount
expected/defined by the user.
      
The binlog_cache_use is incremented when the stmt-cache or the trx-cache is used
and binlog_cache_disk_use is incremented when the disk space from the stmt-cache or the
trx-cache is used. This behavior does not allow to distinguish which cache may be harming
performance due to the extra disk accesses and needs to have its in-memory cache
increased.
      
To fix the problem, we introduced two new options and status variables related to the
stmt-cache:
      
  Options:
      
    . binlog_stmt_cache_size
    . max_binlog_stmt_cache_size
      
    Status Variables:
      
    . binlog_stmt_cache_use
    . binlog_stmt_cache_disk_use

So there are

  . binlog_cache_size that defines the size of the transactional cache for
  updates to transactional engines for the binary log.

  . binlog_stmt_cache_size that defines the size of the statement cache for
  updates to non-transactional engines for the binary log.

  . max_binlog_cache_size that sets the total size of the transactional
  cache.

  . max_binlog_stmt_cache_size that sets the total size of the statement
  cache.

  . binlog_cache_use that identifies the number of transactions that used the
  temporary transactional binary log cache.

  . binlog_cache_disk_use that identifies the number of transactions that used
  the temporary transactional binary log cache but that exceeded the value of
  binlog_cache_size.

  . binlog_stmt_cache_use that identifies the number of statements that used the
  temporary non-transactional binary log cache.

  . binlog_stmt_cache_disk_use that identifies the number of statements that used
  the temporary non-transactional binary log cache but that exceeded the value of
  binlog_stmt_cache_size.
2010-11-05 17:42:37 +00:00
Mats Kindahl
96daec35d1 Bug #57338: Extreneous server variable thread_pool_size
The server contained code for the server variable and
option thread_pool_size, but this server variable where
not used anywhere.

The variable is probably remains from backporting too
much from 6.0 (specifically, the thread pool
implementation was not backported from 6.0, which this
variable is associated with).

This patch eliminates the variable from the server.
2010-10-08 14:22:22 +02:00
Mats Kindahl
5d014b8319 Bug #57338: Extreneous server variable thread_pool_size
The server contained code for the server variable and
option thread_pool_size, but this server variable where
not used anywhere.

The variable is probably remains from backporting too
much from 6.0 (specifically, the thread pool
implementation was not backported from 6.0, which this
variable is associated with).

This patch eliminates the variable from the server.
2010-10-08 14:22:22 +02:00
Luis Soares
06e921818a BUG#54144: ER_SLAVE_HEARTBEAT_VALUE_OUT_OF_RANGE is hard coded
The error message for ER_SLAVE_HEARTBEAT_VALUE_OUT_OF_RANGE was
hard coded. Additionally, the same error was used in three
separate error symptoms: 1. when heartbeat period exceeds the
value of slave_net_timeout, 2. when it is smaller than 1
milisecond and 3. when it was not in range, ie, either negative
or greater than the maximum allowed.
      
We fix this by splitting into three distinct errors and by
removing the message from the source code and moving it to the
errmsg-utf8.txt file.
2010-10-07 16:38:23 +01:00
Luis Soares
cc15d2462c BUG#54144: ER_SLAVE_HEARTBEAT_VALUE_OUT_OF_RANGE is hard coded
The error message for ER_SLAVE_HEARTBEAT_VALUE_OUT_OF_RANGE was
hard coded. Additionally, the same error was used in three
separate error symptoms: 1. when heartbeat period exceeds the
value of slave_net_timeout, 2. when it is smaller than 1
milisecond and 3. when it was not in range, ie, either negative
or greater than the maximum allowed.
      
We fix this by splitting into three distinct errors and by
removing the message from the source code and moving it to the
errmsg-utf8.txt file.
2010-10-07 16:38:23 +01:00
Georgi Kodinov
353739fdef merge of mysql-5.5 into mysql-5.5-wl1054 2010-09-20 17:17:32 +03:00
Georgi Kodinov
dc0b8f7ada merge of mysql-5.5 into mysql-5.5-wl1054 2010-09-20 17:17:32 +03:00
Alexander Nozdrin
f0fe6e4dac Auto-merge from mysql-5.5-merge. 2010-08-30 18:07:40 +04:00
Alexander Nozdrin
dc195adf34 Auto-merge from mysql-5.5-merge. 2010-08-30 18:07:40 +04:00
Marc Alff
19e67ad27c Bug#55576 Two perfschema tests failed on mysql-next-mr-innodb PB2 tests
Before this fix, some tests failed due to lack of instrumentation slots
in the performance schema, because the default sizing was too low.

Now that more code has been instrumented, the default sizing has to be adjusted
to match the current instrumentation consumption.

This change:
- increases the number of rwlock classes from 20 to 30,
- increases the number of rwlock and mutex instances to 1 million.
Both are to account for the volume of data instrumented
when the innodb storage engine is used (because of the innodb buffer pool).

Adjusted the test output accordingly.
2010-08-24 18:21:43 -06:00
Marc Alff
d2df3a8ac5 Bug#55576 Two perfschema tests failed on mysql-next-mr-innodb PB2 tests
Before this fix, some tests failed due to lack of instrumentation slots
in the performance schema, because the default sizing was too low.

Now that more code has been instrumented, the default sizing has to be adjusted
to match the current instrumentation consumption.

This change:
- increases the number of rwlock classes from 20 to 30,
- increases the number of rwlock and mutex instances to 1 million.
Both are to account for the volume of data instrumented
when the innodb storage engine is used (because of the innodb buffer pool).

Adjusted the test output accordingly.
2010-08-24 18:21:43 -06:00
Magne Mahre
a3b9557b3a Bug#55001 Change in behavior: thread_concurrency (docs,
example files)

The system variable 'thread_concurrency' has been
(re-)enabled on all platforms, to prevent startup
errors.

'thread_concurrency' is unused and has no effect,
on any platform, in MySQL 5.1 and later versions.  It 
will be deprecated, and removed, in context of 
worklog WL#5265


mysql-test/include/have_thread_concurrency.inc:
  include/have_thread_concurrency.inc was only needed
  to support platforms that didn't have the
  thread_concurrency variable available.  Since the
  variable is now available on all platforms, the file
  is removed.
2010-08-16 15:05:01 +02:00
Magne Mahre
19c9957367 Bug#55001 Change in behavior: thread_concurrency (docs,
example files)

The system variable 'thread_concurrency' has been
(re-)enabled on all platforms, to prevent startup
errors.

'thread_concurrency' is unused and has no effect,
on any platform, in MySQL 5.1 and later versions.  It 
will be deprecated, and removed, in context of 
worklog WL#5265
2010-08-16 15:05:01 +02:00
Mats Kindahl
b0836bd309 Merging with mysql-5.5-stage. 2010-08-16 14:50:27 +02:00
Mats Kindahl
cd34770558 Merging with mysql-5.5-stage. 2010-08-16 14:50:27 +02:00
Konstantin Osipov
29c4873ad5 Commit on behalf of Dmitry Lenev.
Merge his patch for Bug#52044 into 5.5, and apply 
review comments.
2010-08-12 17:50:23 +04:00
Konstantin Osipov
8673d2b20f Commit on behalf of Dmitry Lenev.
Merge his patch for Bug#52044 into 5.5, and apply 
review comments.
2010-08-12 17:50:23 +04:00
Konstantin Osipov
523066987d A fix for Bug#41158 "DROP TABLE holds LOCK_open during unlink()".
Remove acquisition of LOCK_open around file system operations,
since such operations are now protected by metadata locks.
Rework table discovery algorithm to not require LOCK_open.

No new tests added since all MDL locking operations are covered
in lock.test and mdl_sync.test, and as long as these tests
pass despite the increased concurrency, consistency must be
unaffected.

mysql-test/t/disabled.def:
  Disable NDB tests due to Bug#55799.
sql/datadict.cc:
  No longer necessary to protect ha_create_table() with
  LOCK_open. Serial execution is now ensured by metadata
  locks.
sql/ha_ndbcluster.cc:
  Do not manipulate with LOCK_open in cluster code.
sql/ha_ndbcluster_binlog.cc:
  Do not manipulate with LOCK_open in cluster code.
sql/ha_ndbcluster_binlog.h:
  Update function signature.
sql/handler.cc:
  Implement ha_check_if_table_exists().
  @todo: some engines provide ha_table_exists_in_engine()
  handlerton call, for those we perhaps shouldn't
  call ha_discover(), to be more efficient.
  Since currently it's only NDB, postpone till
  integration with NDB.
sql/handler.h:
  Declare ha_check_if_table_exists() function.
sql/mdl.cc:
  Remove an obsolete comment.
sql/sql_base.cc:
  Update to a new signature of close_cached_tables():
  from now on we always call it without LOCK_open.
  Update comments.
  Remove get_table_share_with_create(), we should
  not attempt to create a table under LOCK_open.
  Introduce get_table_share_with_discover() instead,
  which would request a back off action if the table
  exists in engine.
  Remove acquisition of LOCK_open for 
  data dictionary operations, such as check_if_table_exists().
  Do not use get_table_share_with_create/discover for views,
  where it's not needed.
  Make tdc_remove_table() optionally acquire LOCK_open
  to simplify usage of this function.
  Use the right mutex in the partitioning code when
  manipulating with thd->open_tables.
sql/sql_base.h:
  Update signatures of changes functions.
sql/sql_insert.cc:
  Do not wrap quick_rm_table() with LOCK_open acquisition, 
  this is unnecessary.
sql/sql_parse.cc:
  Update to the new calling convention of tdc_remove_table().
  Update to the new signature of close_cached_tables().
  Update comments.
sql/sql_rename.cc:
  Update to the new calling convention of tdc_remove_table().
  Remove acquisition of LOCK_open around filesystem
  operations.
sql/sql_show.cc:
  Remove get_trigger_table_impl().
  Do not acquire LOCK_open for a dirty read of the trigger
  file.
sql/sql_table.cc:
  Do not acquire LOCK_open for filesystem operations.
sql/sql_trigger.cc:
  Do not require LOCK_open for trigger file I/O.
sql/sql_truncate.cc:
  Update to the new signature of tdc_remove_table().
sql/sql_view.cc:
  Do not require LOCK_open for view I/O.
  Use tdc_remove_table() to expel view share.
  Update comments.
sql/sys_vars.cc:
  Update to the new signature of close_cached_tables().
2010-08-09 22:33:47 +04:00
Konstantin Osipov
f8bfa3287d A fix for Bug#41158 "DROP TABLE holds LOCK_open during unlink()".
Remove acquisition of LOCK_open around file system operations,
since such operations are now protected by metadata locks.
Rework table discovery algorithm to not require LOCK_open.

No new tests added since all MDL locking operations are covered
in lock.test and mdl_sync.test, and as long as these tests
pass despite the increased concurrency, consistency must be
unaffected.
2010-08-09 22:33:47 +04:00
Georgi Kodinov
9705711596 WL#1054: Pluggable authentication support
Merged the implementation to a new base tree.
2010-08-09 11:32:50 +03:00
Georgi Kodinov
881a76699e WL#1054: Pluggable authentication support
Merged the implementation to a new base tree.
2010-08-09 11:32:50 +03:00
Konstantin Osipov
c4c678f653 Merge trunk-bugfixing -> trunk-runtime. 2010-07-27 18:32:42 +04:00
Konstantin Osipov
2abe7b9d4e Merge trunk-bugfixing -> trunk-runtime. 2010-07-27 18:32:42 +04:00
Dmitry Lenev
00496b7acd Fix for bug #52044 "FLUSH TABLES WITH READ LOCK and FLUSH
TABLES <list> WITH READ LOCK are incompatible".

The problem was that FLUSH TABLES <list> WITH READ LOCK
which was issued when other connection has acquired global
read lock using FLUSH TABLES WITH READ LOCK was blocked
and has to wait until global read lock is released.

This issue stemmed from the fact that FLUSH TABLES <list>
WITH READ LOCK implementation has acquired X metadata locks
on tables to be flushed. Since these locks required acquiring
of global IX lock this statement was incompatible with global
read lock.

This patch addresses problem by using SNW metadata type of
lock for tables to be flushed by FLUSH TABLES <list> WITH
READ LOCK. It is OK to acquire them without global IX lock
as long as we won't try to upgrade those locks. Since SNW
locks allow concurrent statements using same table FLUSH
TABLE <list> WITH READ LOCK now has to wait until old
versions of tables to be flushed go away after acquiring
metadata locks. Since such waiting can lead to deadlock
MDL deadlock detector was extended to take into account
waits for flush and resolve such deadlocks.

As a bonus code in open_tables() which was responsible for
waiting old versions of tables to go away was refactored.
Now when we encounter old version of table in open_table()
we don't back-off and wait for all old version to go away,
but instead wait for this particular table to be flushed.
Such approach supported by deadlock detection should reduce
number of scenarios in which FLUSH TABLES aborts concurrent
multi-statement transactions.

Note that active FLUSH TABLES <list> WITH READ LOCK still
blocks concurrent FLUSH TABLES WITH READ LOCK statement
as the former keeps tables open and thus prevents the
latter statement from doing flush.

mysql-test/include/handler.inc:
  Adjusted test case after changing status which is set
  when FLUSH TABLES waits for tables to be flushed from
  "Flushing tables" to "Waiting for table".
mysql-test/r/flush.result:
  Added test which checks that "flush tables <list> with
  read lock" is compatible with active "flush tables with
  read lock" but not vice-versa. This test also covers
  bug #52044 "FLUSH TABLES WITH READ LOCK and FLUSH TABLES
  <list> WITH READ LOCK are incompatible".
mysql-test/r/mdl_sync.result:
  Added scenarios in which wait for table to be flushed
  causes deadlocks to the coverage of MDL deadlock detector.
mysql-test/suite/perfschema/r/dml_setup_instruments.result:
  Adjusted test results after removal of COND_refresh
  condition variable.
mysql-test/suite/perfschema/r/server_init.result:
  Adjusted test and its results after removal of COND_refresh
  condition variable.
mysql-test/suite/perfschema/t/server_init.test:
  Adjusted test and its results after removal of COND_refresh
  condition variable.
mysql-test/t/flush.test:
  Added test which checks that "flush tables <list> with
  read lock" is compatible with active "flush tables with
  read lock" but not vice-versa. This test also covers
  bug #52044 "FLUSH TABLES WITH READ LOCK and FLUSH TABLES
  <list> WITH READ LOCK are incompatible".
mysql-test/t/kill.test:
  Adjusted test case after changing status which is set
  when FLUSH TABLES waits for tables to be flushed from
  "Flushing tables" to "Waiting for table".
mysql-test/t/lock_multi.test:
  Adjusted test case after changing status which is set
  when FLUSH TABLES waits for tables to be flushed from
  "Flushing tables" to "Waiting for table".
mysql-test/t/mdl_sync.test:
  Added scenarios in which wait for table to be flushed
  causes deadlocks to the coverage of MDL deadlock detector.
sql/ha_ndbcluster.cc:
  Adjusted code after adding one more parameter for
  close_cached_tables() call - timeout for waiting for
  table to be flushed.
sql/ha_ndbcluster_binlog.cc:
  Adjusted code after adding one more parameter for
  close_cached_tables() call - timeout for waiting for
  table to be flushed.
sql/lock.cc:
  Removed COND_refresh condition variable. See comment
  for sql_base.cc for details.
sql/mdl.cc:
  Now MDL deadlock detector takes into account information
  about waits for table flushes when searching for deadlock.
  To implement this change:
  - Declaration of enum_deadlock_weight and
    Deadlock_detection_visitor were moved to mdl.h header
    to make them available to the code in table.cc which
    implements deadlock detector traversal through edges
    of waiters graph representing waiting for flush.
  - Since now MDL_context may wait not only for metadata
    lock but also for table to be flushed an abstract
    Wait_for_edge class was introduced. Its descendants
    MDL_ticket and Flush_ticket incapsulate specifics
    of inspecting waiters graph when following through
    edge representing wait of particular type.
  
  We no longer require global IX metadata lock when acquiring
  SNW or SNRW locks. Such locks are needed only when metadata
  locks of these types are upgraded to X locks. This allows
  to use SNW locks in FLUSH TABLES <list> WITH READ LOCK
  implementation and keep the latter compatible with global
  read lock.
sql/mdl.h:
  Now MDL deadlock detector takes into account information
  about waits for table flushes when searching for deadlock.
  To implement this change:
  - Declaration of enum_deadlock_weight and
    Deadlock_detection_visitor were moved to mdl.h header
    to make them available to the code in table.cc which
    implements deadlock detector traversal through edges
    of waiters graph representing waiting for flush.
  - Since now MDL_context may wait not only for metadata
    lock but also for table to be flushed an abstract
    Wait_for_edge class was introduced. Its descendants
    MDL_ticket and Flush_ticket incapsulate specifics
    of inspecting waiters graph when following through
    edge representing wait of particular type.
  - Deadlock_detection_visitor now has m_table_shares_visited
    member which allows to support recursive locking for
    LOCK_open. This is required when deadlock detector
    inspects waiters graph which contains several edges
    representing waits for flushes or needs to come through
    the such edge more than once.
sql/mysqld.cc:
  Removed COND_refresh condition variable. See comment
  for sql_base.cc for details.
sql/mysqld.h:
  Removed COND_refresh condition variable. See comment
  for sql_base.cc for details.
sql/sql_base.cc:
  Changed approach to how threads are waiting for table
  to be flushed. Now thread that wants to wait for old
  table to go away subscribes for notification by adding
  Flush_ticket to table's share and waits using
  MDL_context::m_wait object. Once table gets flushed
  (i.e. all tables are closed and table share is ready
  to be destroyed) all such waiters are notified
  individually.
  Thanks to this change MDL deadlock detector can take
  such waits into account.
  
  To implement this/as result of this change:
  - tdc_wait_for_old_versions() was replaced with
    tdc_wait_for_old_version() which waits for individual
    old share to go away and which is called by open_table()
    after finding out that share is outdated. We don't
    need to perform back-off before such waiting thanks
    to the fact that deadlock detector now sees such waits.
  - As result Open_table_ctx::m_mdl_requests became
    unnecessary and was removed. We no longer allocate
    copies of MDL_request objects on MEM_ROOT when
    MYSQL_OPEN_FORCE_SHARED/SHARED_HIGH_PRIO flags are
    in effect.
  - close_cached_tables() and tdc_wait_for_old_version()
    share code which implements waiting for share to be
    flushed - the both use TABLE_SHARE::wait_until_flush()
    method. Thanks to this close_cached_tables() supports
    timeouts and has extra parameter for this.
  - Open_table_context::OT_MDL_CONFLICT enum element was
    renamed to OT_CONFLICT as it is now also used in cases
    when back-off is required to resolve deadlock caused
    by waiting for flush and not metadata lock.
  - In cases when we discover that current connection tries
    to open tables from different generation we now simply
    back-off and restart process of opening tables. To
    support this Open_table_context::OT_REOPEN_TABLES enum
    element was added.
  - COND_refresh condition variable became unnecessary and
    was removed.
  - mysql_notify_thread_having_shared_lock() no longer wakes
    up connections waiting for flush as all such connections
    can be waken up by deadlock detector if necessary.
sql/sql_base.h:
  - close_cached_tables() now has one more parameter -
    timeout for waiting for table to be flushed.
  - Open_table_context::OT_MDL_CONFLICT enum element was
    renamed to OT_CONFLICT as it is now also used in cases
    when back-off is required to resolve deadlock caused
    by waiting for flush and not metadata lock.
    Added new OT_REOPEN_TABLES enum element to be used in
    cases when we need to restart open tables process even
    in the middle of transaction.
  - Open_table_ctx::m_mdl_requests became unnecessary and
    was removed.
sql/sql_class.h:
  Added assert ensuring that we won't use LOCK_open mutex
  with THD::enter_cond(). Otherwise deadlocks can arise in
  MDL deadlock detector.
sql/sql_parse.cc:
  Changed FLUSH TABLES <list> WITH READ LOCK to take SNW
  metadata locks instead of X locks on tables to be flushed.
  Since we no longer require global IX lock to be taken
  when SNW locks are taken this makes this statement
  compatible with FLUSH TABLES WITH READ LOCK statement.
  Since SNW locks allow other connections to have table
  opened FLUSH TABLES <list> WITH READ LOCK now has to
  wait during open_tables() for old version to go away.
  Such waits can lead to deadlocks which will be detected
  by MDL deadlock detector which now takes waits for table
  to be flushed into account.
  
  Also adjusted code after adding one more parameter for
  close_cached_tables() call - timeout for waiting for
  table to be flushed.
sql/sql_yacc.yy:
  FLUSH TABLES <list> WITH READ LOCK now needs only SNW
  metadata locks on tables.
sql/sys_vars.cc:
  Adjusted code after adding one more parameter for
  close_cached_tables() call - timeout for waiting for
  table to be flushed.
sql/table.cc:
  Implemented new approach to how threads are waiting for
  table to be flushed. Now thread that wants to wait for
  old table to go away subscribes for notification by
  adding Flush_ticket to table's share and waits using
  MDL_context::m_wait object. Once table gets flushed
  (i.e. all tables are closed and table share is ready
  to be destroyed) all such waiters are notified
  individually. This change allows to make such waits
  visible inside of MDL deadlock detector.
  To do it:
  
  - Added list of waiters/Flush_tickets to TABLE_SHARE
    class.
  - Changed free_table_share() to postpone freeing of
    share memory until last waiter goes away and to
    wake up subscribed waiters.
  - Added TABLE_SHARE::wait_until_flushed() method which
    implements subscription to the list of waiters for
    table to be flushed and waiting for this event.
  
  Implemented interface which allows to expose waits for
  flushes to MDL deadlock detector:
  
  - Introduced Flush_ticket class a descendant of
    Wait_for_edge class.
  - Added TABLE_SHARE::find_deadlock() method which allows
    deadlock detector to find out what contexts are still
    using old version of table in question (i.e. to find
    out what contexts are waited for by owner of
    Flush_ticket).
sql/table.h:
  In order to support new strategy of waiting for table flush
  (see comment for table.cc for details) added list of
  waiters/Flush_tickets to TABLE_SHARE class.
  
  Implemented interface which allows to expose waits for
  flushes to MDL deadlock detector:
  - Introduced Flush_ticket class a descendant of
    Wait_for_edge class.
  - Added TABLE_SHARE::find_deadlock() method which allows
    deadlock detector to find out what contexts are still
    using old version of table in question (i.e. to find
    out what contexts are waited for by owner of
    Flush_ticket).
2010-07-27 17:34:58 +04:00
Dmitry Lenev
5fff906edd Fix for bug #52044 "FLUSH TABLES WITH READ LOCK and FLUSH
TABLES <list> WITH READ LOCK are incompatible".

The problem was that FLUSH TABLES <list> WITH READ LOCK
which was issued when other connection has acquired global
read lock using FLUSH TABLES WITH READ LOCK was blocked
and has to wait until global read lock is released.

This issue stemmed from the fact that FLUSH TABLES <list>
WITH READ LOCK implementation has acquired X metadata locks
on tables to be flushed. Since these locks required acquiring
of global IX lock this statement was incompatible with global
read lock.

This patch addresses problem by using SNW metadata type of
lock for tables to be flushed by FLUSH TABLES <list> WITH
READ LOCK. It is OK to acquire them without global IX lock
as long as we won't try to upgrade those locks. Since SNW
locks allow concurrent statements using same table FLUSH
TABLE <list> WITH READ LOCK now has to wait until old
versions of tables to be flushed go away after acquiring
metadata locks. Since such waiting can lead to deadlock
MDL deadlock detector was extended to take into account
waits for flush and resolve such deadlocks.

As a bonus code in open_tables() which was responsible for
waiting old versions of tables to go away was refactored.
Now when we encounter old version of table in open_table()
we don't back-off and wait for all old version to go away,
but instead wait for this particular table to be flushed.
Such approach supported by deadlock detection should reduce
number of scenarios in which FLUSH TABLES aborts concurrent
multi-statement transactions.

Note that active FLUSH TABLES <list> WITH READ LOCK still
blocks concurrent FLUSH TABLES WITH READ LOCK statement
as the former keeps tables open and thus prevents the
latter statement from doing flush.
2010-07-27 17:34:58 +04:00