Problem:
When the user specified foreign key name contains "_ibfk_", InnoDB wrongly
tries to rename it.
Solution:
When a table is renamed, all its associated foreign keys will also be renamed,
only if the foreign key names are automatically generated. If the foreign key
names are given by the user, even if it has _ibfk_ in it, it must not be
renamed.
rb#2935 approved by Jimmy, Krunal and Satya
SERIALIZABLE
Problem:
The documentation claims that WITH CONSISTENT SNAPSHOT will work for both
REPEATABLE READ and SERIALIZABLE isolation levels. But it will work only
for REPEATABLE READ isolation level. Also, the clause WITH CONSISTENT
SNAPSHOT is silently ignored when it is not applicable to the given isolation
level.
Solution:
Generate a warning when the clause WITH CONSISTENT SNAPSHOT is ignored.
rb#2797 approved by Kevin.
Note: Support team wanted to push this to 5.5+.
SERIALIZABLE
Problem:
The documentation claims that WITH CONSISTENT SNAPSHOT will work for both
REPEATABLE READ and SERIALIZABLE isolation levels. But it will work only
for REPEATABLE READ isolation level. Also, the clause WITH CONSISTENT
SNAPSHOT is silently ignored when it is not applicable to the given isolation
level.
Solution:
Generate a warning when the clause WITH CONSISTENT SNAPSHOT is ignored.
rb#2797 approved by Kevin.
Note: Support team wanted to push this to 5.5+.
Analysis
--------
The pthread_mutex commit_threads_m was initiliazed but never
used.
Fix
---
Removing the commit_threads_m mutex from the code base.
[ Approved by Marko rb#2475]
Analysis
--------
The pthread_mutex commit_threads_m was initiliazed but never
used.
Fix
---
Removing the commit_threads_m mutex from the code base.
[ Approved by Marko rb#2475]
DDL AND I_S QUERIES
Skip partially created indexes (ones whose name starts with TEMP_INDEX_PREFIX)
from stats gathering.
Because InnoDB reports HA_INPLACE_ADD_INDEX_NO_WRITE to MySQL, the latter
allows parallel execution of ha_innobase::add_index() and ha_innobase::info().
Reviewed by: Inaam (rb:2613)
DDL AND I_S QUERIES
Skip partially created indexes (ones whose name starts with TEMP_INDEX_PREFIX)
from stats gathering.
Because InnoDB reports HA_INPLACE_ADD_INDEX_NO_WRITE to MySQL, the latter
allows parallel execution of ha_innobase::add_index() and ha_innobase::info().
Reviewed by: Inaam (rb:2613)
IF IT HAS A WRONG COUNT
If CHECK TABLE finds that a secondary index contains the wrong
number of entries, it used to report an error but not mark the
index as corrupt. The error means that the index should be rebuilt,
which can be done with ALTER TABLE DROP INDEX and ALTER TABLE ADD
INDEX. But just in case the DBA does not pay any attention to the
output of CHECK TABLE, the secondary index should be marked as
corrupted so that it is not used again.
Approved by Inaam in RB:2607
IF IT HAS A WRONG COUNT
If CHECK TABLE finds that a secondary index contains the wrong
number of entries, it used to report an error but not mark the
index as corrupt. The error means that the index should be rebuilt,
which can be done with ALTER TABLE DROP INDEX and ALTER TABLE ADD
INDEX. But just in case the DBA does not pay any attention to the
output of CHECK TABLE, the secondary index should be marked as
corrupted so that it is not used again.
Approved by Inaam in RB:2607
AFTER A ROW IS READ
Approved by: Sunny Bains rb://2425
Don't release concurrency tickets when asked to release
btr_search_latch. This is a 5.5 only bug. It is already
fixed in 5.6 upwards.
AFTER A ROW IS READ
Approved by: Sunny Bains rb://2425
Don't release concurrency tickets when asked to release
btr_search_latch. This is a 5.5 only bug. It is already
fixed in 5.6 upwards.
TRANSACTION ROLLBACK
Problem:
=======
"prepare_commit_mutex" is acquired during "innobase_xa_prepare"
and it is freed only in "innobase_commit". After prepare,
if the commit operation fails the transaction is rolled back
but the mutex is not released.
Analysis:
========
During transaction commit process transaction is prepared and
the "prepare_commit_mutex" is acquired to preserve the order
of commit. After prepare write to binlog is initiated.
File: sql/handler.cc
if (error || (is_real_trans && xid &&
-----> (error= !(cookie= tc_log->log_xid(thd, xid)))))
{
ha_rollback_trans(thd, all);
In the above code "tc_log->log_xid" operation fails.
When the write to binlog fails the transaction is rolled back
with out freeing the mutex. A subsequent "INSERT" operation
tries to acquire the same mutex during its commit process
and the server aborts.
Fix:
===
"prepare_commit_mutex" is freed during "innobase_rollback".
storage/innobase/handler/ha_innodb.cc:
Added code to free "prepare_commit_mutex"
TRANSACTION ROLLBACK
Problem:
=======
"prepare_commit_mutex" is acquired during "innobase_xa_prepare"
and it is freed only in "innobase_commit". After prepare,
if the commit operation fails the transaction is rolled back
but the mutex is not released.
Analysis:
========
During transaction commit process transaction is prepared and
the "prepare_commit_mutex" is acquired to preserve the order
of commit. After prepare write to binlog is initiated.
File: sql/handler.cc
if (error || (is_real_trans && xid &&
-----> (error= !(cookie= tc_log->log_xid(thd, xid)))))
{
ha_rollback_trans(thd, all);
In the above code "tc_log->log_xid" operation fails.
When the write to binlog fails the transaction is rolled back
with out freeing the mutex. A subsequent "INSERT" operation
tries to acquire the same mutex during its commit process
and the server aborts.
Fix:
===
"prepare_commit_mutex" is freed during "innobase_rollback".
Bug #16754901 PARS_INFO_FREE NOT CALLED IN DICT_CREATE_ADD_FOREIGN_TO_DICTIONARY
Problem:
There are two situations here. The constraint name is explicitly
given by the user and the constraint name is automatically generated
by InnoDB. In the case of generated constraint name, it is formed by
adding table name as prefix. The table names are stored internally in
my_charset_filename. In the case of constraint name explicitly given
by the user, it is stored in UTF8 format itself. So, in some
situations the constraint name is in utf8 and in some situations it is
in my_charset_filename format. Hence this problem.
Solution:
Always store the foreign key constraint name in UTF-8 even when
automatically generated.
Bug #16754901 PARS_INFO_FREE NOT CALLED IN DICT_CREATE_ADD_FOREIGN_TO_DICTIONARY
Problem:
There was a memory leak in the function dict_create_add_foreign_to_dictionary().
The allocated pars_info_t object is not freed in the error code path.
Solution:
Allocate the pars_info_t object after the error checking.
rb#2368 in review
Bug #16754901 PARS_INFO_FREE NOT CALLED IN DICT_CREATE_ADD_FOREIGN_TO_DICTIONARY
Problem:
There are two situations here. The constraint name is explicitly
given by the user and the constraint name is automatically generated
by InnoDB. In the case of generated constraint name, it is formed by
adding table name as prefix. The table names are stored internally in
my_charset_filename. In the case of constraint name explicitly given
by the user, it is stored in UTF8 format itself. So, in some
situations the constraint name is in utf8 and in some situations it is
in my_charset_filename format. Hence this problem.
Solution:
Always store the foreign key constraint name in UTF-8 even when
automatically generated.
Bug #16754901 PARS_INFO_FREE NOT CALLED IN DICT_CREATE_ADD_FOREIGN_TO_DICTIONARY
Problem:
There was a memory leak in the function dict_create_add_foreign_to_dictionary().
The allocated pars_info_t object is not freed in the error code path.
Solution:
Allocate the pars_info_t object after the error checking.
rb#2368 in review
OPENING MISSING PARTITION
In the ha_innobase::open() call, for normal tables, there is no retry logic.
But for partitioned tables, there is a retry logic introduced as fix for:
http://bugs.mysql.com/bug.php?id=33349https://support.mysql.com/view.php?id=21080
The Bug#33349, does not provide sufficient information to analyze the original
problem. The original problem reported by bug#33349 is also minor (just an
annoyance and no loss of functionality). Most importantly, the retry logic
has been introduced without any associated test case.
So we are removing the retry logic for partitioned tables. When the original
problem occurs, a different solution will be explored.
OPENING MISSING PARTITION
In the ha_innobase::open() call, for normal tables, there is no retry logic.
But for partitioned tables, there is a retry logic introduced as fix for:
http://bugs.mysql.com/bug.php?id=33349https://support.mysql.com/view.php?id=21080
The Bug#33349, does not provide sufficient information to analyze the original
problem. The original problem reported by bug#33349 is also minor (just an
annoyance and no loss of functionality). Most importantly, the retry logic
has been introduced without any associated test case.
So we are removing the retry logic for partitioned tables. When the original
problem occurs, a different solution will be explored.
Change default for innodb_use_fallocate to FALSE, due to bugs in older Linux kernels (posix_fallocate() does not always guarantee that file size is like one specified)
UPDATES
After checking that the table has changed too much in
row_update_statistics_if_needed() and calling dict_update_statistics(),
also check if the same condition holds after acquiring the table stats
latch. This is to avoid multiple threads concurrently entering and
executing the stats update code.
Approved by: Marko (rb:2186)
UPDATES
After checking that the table has changed too much in
row_update_statistics_if_needed() and calling dict_update_statistics(),
also check if the same condition holds after acquiring the table stats
latch. This is to avoid multiple threads concurrently entering and
executing the stats update code.
Approved by: Marko (rb:2186)
This is a deadlock that will also be fixed in the server by
Bug #11844915 - HANG IN THDVAR MUTEX ACQUISITION.
So this is a simple alternate method of fixing the same problem,
but from within InnoDB.
The simple change is to make rename table start a transaction
before locking dict_sys->mutex since thd_supports_xa() can call
THDVAR which can lock a mutex, LOCK_global_system_variables, that
is used in the server by many other activities. At least one of
those, sys_var::update(), can call back into InnoDB and try to
lock dict_sys->mutex while holding LOCK_global_system_variables.
The other bug fix for 11844915 eliminates the use of
LOCK_global_system_variables for calls to THDVAR.
Approved by marko in http://rb.no.oracle.com/rb/r/2000/
This is a deadlock that will also be fixed in the server by
Bug #11844915 - HANG IN THDVAR MUTEX ACQUISITION.
So this is a simple alternate method of fixing the same problem,
but from within InnoDB.
The simple change is to make rename table start a transaction
before locking dict_sys->mutex since thd_supports_xa() can call
THDVAR which can lock a mutex, LOCK_global_system_variables, that
is used in the server by many other activities. At least one of
those, sys_var::update(), can call back into InnoDB and try to
lock dict_sys->mutex while holding LOCK_global_system_variables.
The other bug fix for 11844915 eliminates the use of
LOCK_global_system_variables for calls to THDVAR.
Approved by marko in http://rb.no.oracle.com/rb/r/2000/
FROM SHOW CREATE
Problem: The length of the internally generated foreign key name
is not checked.
Solution: The length of the internally generated foreign key name is
checked. If it is greater than the allowed limit, an error message
is reported. Also, the constraint name is printed in the same manner
as the table name, using the system charset information.
rb://1969 approved by Marko.
FROM SHOW CREATE
Problem: The length of the internally generated foreign key name
is not checked.
Solution: The length of the internally generated foreign key name is
checked. If it is greater than the allowed limit, an error message
is reported. Also, the constraint name is printed in the same manner
as the table name, using the system charset information.
rb://1969 approved by Marko.
