Problem was that in-place online alter table was used on a table
that had mismatch between MySQL frm file and InnoDB data dictionary.
Fixed so that traditional "Copy" method is used if the MySQL frm
and InnoDB data dictionary is not consistent.
Merged Facebook commit dd2d11be7aaf3be270e740fb95cbc4eacb52f4d7
authored by Rongrong Zhong from https://github.com/facebook/mysql-5.6
This fixes MySQL Bug #68220 innodb_rows_updated is misleading on slave
http://bugs.mysql.com/bug.php?id=68220
Added innodb_system_rows_read/inserted/updated/deleted counters
that are the equivalent of innodb_rows_* but that only account for
changes made to system databases (mysql, information_schame and
preformance_schema). These counters will be used on slaves to
differentiated the updates made on system databases from those made on
user databases.
innodb_rows_* status counters are not updated when innodb_system_rows_*
are updated.
dd2d11be7a
If mysql.innodb_table_stats or mysql.innodb_index_stats is not found or has
unexpected structure output that error only once and no other error for
every table trying to use them. If they do exists, then print fetch or
recalculation errors only once / table or index.
SLOW/CRASHES SEMAPHORE
Problem:
There are 2 lakh tables - fk_000001, fk_000002 ... fk_200000. All of them
are related to the same parent_table through a foreign key constraint.
When the parent_table is loaded into the dictionary cache, all the child table
will also be loaded. This is taking lot of time. Since this operation happens
when the dictionary latch is taken, the scenario leads to "long semaphore wait"
situation and the server gets killed.
Analysis:
A simple performance analysis showed that the slowness is because of the
dict_foreign_find() function. It does a linear search on two linked list
table->foreign_list and table->referenced_list, looking for a particular
foreign key object based on foreign->id as the key. This is called two
times for each foreign key object.
Solution:
Introduce a rb tree in table->foreign_rbt and table->referenced_rbt, which
are some sort of index on table->foreign_list and table->referenced_list
respectively, using foreign->id as the key. These rbt structures will be
solely used by dict_foreign_find().
rb#5599 approved by Vasil
Update InnoDB to 5.6.14
Apply MySQL-5.6 hack for MySQL Bug#16434374
Move Aria-only HA_RTREE_INDEX from my_base.h to maria_def.h (breaks an assert in InnoDB)
Fix InnoDB memory leak
TABLE/KEY RELATIONS
The DICT_FK_MAX_RECURSIVE_LOAD was reduced from 250 to 33 in rb#2058.
But in optimized build, this recursive depth is still too deep and
resulted in stack overflow. So reducing this depth to 20 now.
TABLE/KEY RELATIONS
Problem:
When there are many tables, linked together through the foreign key
constraints, then loading one table will recursively open other tables. This
can sometimes lead to thread stack overflow. In such situations the server
will exit.
I see the stack overflow problem when the thread_stack is 196608 (the default
value for 32-bit systems). I don't see the problem when the thread_stack is
set to 262144 (the default value for 64-bit systems).
Solution:
Currently, in InnoDB, there is a macro DICT_FK_MAX_RECURSIVE_LOAD which defines
the maximum number of tables that will be loaded recursively because of foreign
key relations. This is currently set to 250. We can reduce this number to 33
(anything more than 33 does not solve the problem for the default value). We
can keep it small enough so that thread stack overflow does not happen for the
default values. Reducing the DICT_FK_MAX_RECURSIVE_LOAD will not affect the
functionality of InnoDB. The tables will eventually be loaded.
rb#2058 approved by Marko
TABLE/KEY RELATIONS
Problem:
When there are many tables, linked together through the foreign key
constraints, then loading one table will recursively open other tables. This
can sometimes lead to thread stack overflow. In such situations the server
will exit.
I see the stack overflow problem when the thread_stack is 196608 (the default
value for 32-bit systems). I don't see the problem when the thread_stack is
set to 262144 (the default value for 64-bit systems).
Solution:
Currently, in InnoDB, there is a macro DICT_FK_MAX_RECURSIVE_LOAD which defines
the maximum number of tables that will be loaded recursively because of foreign
key relations. This is currently set to 250. We can reduce this number to 33
(anything more than 33 does not solve the problem for the default value). We
can keep it small enough so that thread stack overflow does not happen for the
default values. Reducing the DICT_FK_MAX_RECURSIVE_LOAD will not affect the
functionality of InnoDB. The tables will eventually be loaded.
rb#2058 approved by Marko
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)
We did not allocate enough bits for index->trx_id_offset, causing an
UPDATE or DELETE of a table with a PRIMARY KEY longer than 1024 bytes
to corrupt the PRIMARY KEY.
dict_index_t: Allocate enough bits.
dict_index_build_internal_clust(): Check for overflow of
index->trx_id_offset. Trip a debug assertion when overflow occurs.
rb:1380 approved by Jimmy Yang
Also addressed issues in bug #11745133, where we could mark a table
corrupted instead of crashing the server when found a corrupted buffer/page
if the table created with innodb_file_per_table on.
With this change, the index prefix column length lifted from 767 bytes
to 3072 bytes if "innodb_large_prefix" is set to "true".
rb://603 approved by Marko
The innoDB global variable srv_lower_case_table_names is set to the value of lower_case_table_names declared in mysqld.h server in ha_innodb.cc. Since this variable can change at runtime, it is reset for each handler call to ::create, ::open, ::rename_table & ::delete_table.
But it is possible for tables to be implicitly opened before an explicit handler call is made when an engine is first started or restarted. I was able to reproduce that with the testcase in this patch on a version of InnoDB from 2 weeks ago. It seemed like the change buffer entries for the secondary key was getting put into pages after the restart. (But I am not sure, I did not write down the call stack while it was reproducing.) In the current code, the implicit open, which is actually a call to dict_load_foreigns(), does not occur with this testcase.
The change is to replace srv_lower_case_table_names by an interface function in innodb.cc that retrieves the server global variable when it is needed.
"rows examined" estimates". This change implements "innodb_stats_method"
with options of "nulls_equal", "nulls_unequal" and "null_ignored".
rb://553 approved by Marko
InnoDB does not attempt to handle lower_case_table_names == 2 when looking
up foreign table names and referenced table name. It turned that server
variable into a boolean and ignored the possibility of it being '2'.
The setting lower_case_table_names == 2 means that it should be stored and
displayed in mixed case as given, but compared internally in lower case.
Normally the server deals with this since it stores table names. But
InnoDB stores referential constraints for the server, so it needs to keep
track of both lower case and given names.
This solution creates two table name pointers for each foreign and referenced
table name. One to display the name, and one to look it up. Both pointers
point to the same allocated string unless this setting is 2. So the overhead
added is not too much.
Two functions are created in dict0mem.c to populate the ..._lookup versions
of these pointers. Both dict_mem_foreign_table_name_lookup_set() and
dict_mem_referenced_table_name_lookup_set() are called 5 times each.
