innodb_stats_sample_pages
Analysis: If you set the number of analyzed pages
to very low number compared to actual pages on
that table/index it randomly pics those pages
(default 8 pages), this leads to fact that query
after analyze table returns different results. If
the index tree is small, smaller than 10 *
n_sample_pages + total_external_size, then the
estimate is ok. For bigger index trees it is
common that we do not see any borders between
key values in the few pages we pick. But still
there may be n_sample_pages different key values,
or even more. And it just tries to
approximate to n_sample_pages (8).
Fix: (1) Introduced new dynamic configuration variable
innodb_stats_sample_traditional that retains
the current design. Default false.
(2) If traditional sample is not used we use
n_sample_pages = max(min(srv_stats_sample_pages,
index->stat_index_size),
log2(index->stat_index_size)*
srv_stats_sample_pages);
(3) Introduced new dynamic configuration variable
stat_modified_counter (default = 0) if set
sets lower bound for row updates when statistics is re-estimated.
If user has provided upper bound for how many rows needs to be updated
before we calculate new statistics we use minimum of provided value
and 1/16 of table every 16th round. If no upper bound is provided
(srv_stats_modified_counter = 0, default) then calculate new statistics
if 1 / 16 of table has been modified
since the last time a statistics batch was run.
We calculate statistics at most every 16th round, since we may have
a counter table which is very small and updated very often.
@param t table
@return true if the table has changed too much and stats need to be
recalculated
*/
#define DICT_TABLE_CHANGED_TOO_MUCH(t) \
((ib_int64_t) (t)->stat_modified_counter > (srv_stats_modified_counter ? \
ut_min(srv_stats_modified_counter, (16 + (t)->stat_n_rows / 16)) : \
16 + (t)->stat_n_rows / 16))
use the same restriction for character_set_client on the command line
and from SQL.
Also: remove strange hack from thd_init_client_charset() that contradicted
the manual (collation_connection and character_set_result were not always set)
Merge Facebook commit cd063ab930
authored by Peng Tian from https://github.com/facebook/mysql-5.6
Introduced a new configuration variable innodb_fatal_semaphore_wait_threshold,
it makes the fatal semaphore timeout configurable. Modified original commit
so that no MariaDB server files are changed, instead introduced a new
InnoDB/XtraDB configuration variable.
Its default/min/max vlaues are 600/1/2^32-1 in seconds (it was hardcoded
as 600, now its default value is 600, so the default behavior of this diff
should be no change).
setting of innodb_io_capacity_max
(a) Changed the behaviour so that if you set innodb_io_capacity to a
value > innodb_io_capacity_max that the value is accepted AND
that innodb_io_capacity_max = innodb_io_capacity * 2.
(b) If someone wants to reduce innodb_io_capacity_max and
reduce it below innodb_io_capacity then innodb_io_capacity
should be reduced to the same level as innodb_io_capacity_max.
In both cases give a warning to user.
Merged Facebook commit 617aef9f911d825e9053f3d611d0389e02031225
authored by Inaam Rana to InnoDB storage engine (not XtraDB)
from https://github.com/facebook/mysql-5.6
WL#7047 - Optimize buffer pool list scans and related batch processing
Reduce excessive scanning of pages when doing flush list batches. The
fix is to introduce the concept of "Hazard Pointer", this reduces the
time complexity of the scan from O(n*n) to O.
The concept of hazard pointer is reversed in this work. Academically
hazard pointer is a pointer that the thread working on it will declar
such and as long as that thread is not done no other thread is allowe
do anything with it.
In this WL we declare the pointer as a hazard pointer and then if any
thread attempts to work on it, it is allowed to do so but it has to a
the hazard pointer to the next valid value. We use hazard pointer sol
reverse traversal of lists within a buffer pool instance.
Add an event to control the background flush thread. The background f
thread wait has been converted to an os event timed wait so that it c
signalled by threads that want to kick start a background flush when
buffer pool is running low on free/dirty pages.
Merge Facebook commit 154c579b828a60722a7d9477fc61868c07453d08
and e8f0052f9b112dc786bf9b957ed5b16a5749f7fd authored
by Steaphan Greene from https://github.com/facebook/mysql-5.6
Optimize prefix index queries to skip cluster index lookup when possible.
Currently InnoDB will always fetch the clustered index (primary key
index) for all prefix columns in an index, even when the value of a
particular record is smaller than the prefix length. This change
optimizes that case to use the record from the secondary index and avoid
the extra lookup.
Also adds two status vars that track how effective this is:
innodb_secondary_index_triggered_cluster_reads:
Times secondary index lookup triggered cluster lookup.
innodb_secondary_index_triggered_cluster_reads_avoided:
Times prefix optimization avoided triggering cluster lookup.
Merge Facebook commit 4f3e0343fd2ac3fc7311d0ec9739a8f668274f0d
authored by Steaphan Greene from https://github.com/facebook/mysql-5.6
Adds innodb_idle_flush_pct to enable tuning of the page flushing rate
when the system is relatively idle. We care about this, since doing
extra unnecessary flash writes shortens the lifespan of the flash.
Merge Facebook commit ca40b4417fd224a68de6636b58c92f133703fc68
authored by Steaphan Greene from https://github.com/facebook/mysql-5.6
Change the default value for innodb_log_compressed_pages to false
Logging these pages is a waste. We don't want this to be enabled.
One caution here: If the zlib version used by innodb is changed, but
the running version is still the previous version, and the running
version crashes, it is possible crash recovery could fail.
When crash recovery uses a zlib version at all different than the
version used by the crashed instance, it is possible that a redone
compression could fail, where the original did not, because the new
zlib version compresses the same data to a slightly larger size.
Because of the nature of compression, this is even possible when
upgrading to a version of zlib which actually peforms overall better
compression than the previous version.
If this happens, mysql will fail to recover, since a page split can
not be safely triggered during crash recovery.
So, either the exact zlib version must be controlled between builds,
or these rare recovery failures must be accepted. The cost of
logging these pages is quite high, so we consider this limitation to
be worthwhile.
This failure scenario can not happen if there was a clean shutdown.
This is only relevant to restarting crashed instances, or starting an
instance built via a hot backup too (XtraBackup).
New generation hard drives, SSDs and NVM devices support 4K
sector size. Supported sector size can be found using fstatvfs()
or GetDiskFreeSpace() functions.
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
Merged Facebook commit ecff018632c6db49bad73d9233c3cdc9f41430e9
authored by Steaphan Greene from https://github.com/facebook/mysql-5.6
This change is to fix: http://bugs.mysql.com/62534
This makes innodb_max_dirty_pages_pct a double with min,default,max values
0.001, 75, 99.999.
This also makes innodb_max_dirty_pages_pct_lwm and adaptive_flushing_lwm
doubles, as these sysvars are inter-dependent.
Added more to the BUFFER POOL AND MEMORY section of SHOW INNODB STATUS:
Percent pages dirty: X.X
This is all n_dirty_pages / used_pages
Percent all pages dirty: X.X
This is all n_dirty_pages / all-pages
Max dirty pages percent: X.X
This is innodb_max_dirty_pages_pct
Also changed all of buf from 2 to 3 digits of precision (%.2f -> %.3f).
Extend existing plugins to support
* SHOW QUERY_RESPONSE_TIME
* FLUSH QUERY_RESPONSE_TIME
* SHOW LOCALE
move userstat tables to use the new API instead of
hand-coded syntax
* ignore the OPTIMIZER_SWITCH_ENGINE_CONDITION_PUSHDOWN bit
* issue a deprecation warning on 'engine_condition_pushdown=on'
* remove unused remains of the old pre-5.5 engine_condition_pushdown variable
Added MAX_STATEMENT_TIME user variable to automaticly kill queries after a given time limit has expired.
- Added timer functions based on pthread_cond_timedwait
- Added kill_handlerton() to signal storage engines about kill/timeout
- Added support for GRANT ... MAX_STATEMENT_TIME=#
- Copy max_statement_time to current user, if stored in mysql.user
- Added status variable max_statement_time_exceeded
- Added KILL_TIMEOUT
- Removed digest hash from performance schema tests as they change all the time.
- Updated test results that changed because of the new user variables or new fields in mysql.user
This functionallity is inspired by work done by Davi Arnaut at twitter.
Test case is copied from Davi's work.
Documentation can be found at
https://kb.askmonty.org/en/how-to-limittimeout-queries/
mysql-test/r/mysqld--help.result:
Updated for new help message
mysql-test/suite/perfschema/r/all_instances.result:
Added new mutex
mysql-test/suite/sys_vars/r/max_statement_time_basic.result:
Added testing of max_statement_time
mysql-test/suite/sys_vars/t/max_statement_time_basic.test:
Added testing of max_statement_time
mysql-test/t/max_statement_time.test:
Added testing of max_statement_time
mysys/CMakeLists.txt:
Added thr_timer
mysys/my_init.c:
mysys/mysys_priv.h:
Added new mutex and condition variables
Added new mutex and condition variables
mysys/thr_timer.c:
Added timer functions based on pthread_cond_timedwait()
This can be compiled with HAVE_TIMER_CREATE to benchmark agains timer_create()/timer_settime()
sql/lex.h:
Added MAX_STATEMENT_TIME
sql/log_event.cc:
Safety fix (timeout should be threated as an interrupted query)
sql/mysqld.cc:
Added support for timers
Added status variable max_statement_time_exceeded
sql/share/errmsg-utf8.txt:
Added ER_QUERY_TIMEOUT
sql/signal_handler.cc:
Added support for KILL_TIMEOUT
sql/sql_acl.cc:
Added support for GRANT ... MAX_STATEMENT_TIME=#
Copy max_statement_time to current user
sql/sql_class.cc:
Added timer functionality to THD.
Added thd_kill_timeout()
sql/sql_class.h:
Added timer functionality to THD.
Added KILL_TIMEOUT
Added max_statement_time variable in similar manner as long_query_time was done.
sql/sql_connect.cc:
Added handling of max_statement_time_exceeded
sql/sql_parse.cc:
Added starting and stopping timers for queries.
sql/sql_show.cc:
Added max_statement_time_exceeded for user/connects status in MariaDB 10.0
sql/sql_yacc.yy:
Added support for GRANT ... MAX_STATEMENT_TIME=# syntax, to be enabled in 10.0
sql/structs.h:
Added max_statement_time user resource
sql/sys_vars.cc:
Added max_statement_time variables
mysql-test/suite/roles/create_and_drop_role_invalid_user_table.test
Removed test as we require all fields in mysql.user table.
scripts/mysql_system_tables.sql
scripts/mysql_system_tables_data.sql
scripts/mysql_system_tables_fix.sql
Updated mysql.user with new max_statement_time field
Merged lp:maria/maria-10.0-galera up to revision 3880.
Added a new functions to handler API to forcefully abort_transaction,
producing fake_trx_id, get_checkpoint and set_checkpoint for XA. These
were added for future possiblity to add more storage engines that
could use galera replication.
Merged lp:maria/maria-10.0-galera up to revision 3879.
Added a new functions to handler API to forcefully abort_transaction,
producing fake_trx_id, get_checkpoint and set_checkpoint for XA. These
were added for future possiblity to add more storage engines that
could use galera replication.
mysqldump:
- Added --log-queries to allow one to disable logging for the dump
sql/log_event.cc:
- Removed setting of enable_slow_log as it's not required anymore.
sql/sql_parse.cc:
- Set enable_slow_log to value of thd->variables.sql_log_slow as this will speed up tests if slow log is disabled.
- opt_log_slow_admin_statements can now only disable slow log, not enable it.
sql/sql_explain.cc:
- Minor cleanup
Other things:
- Added sql_log_slow to system variables.
- Changed opt_slow_log to global_system_variables.sql_log_slow in all files
- Updated tests to reflect changes
~40% bugfixed(*) applied
~40$ bugfixed reverted (incorrect or we're not buggy)
~20% bugfixed applied, despite us being not buggy
(*) only changes in the server code, e.g. not cmakefiles
Reason for the problem was that the hash of changed files in the key cache was too small (was 128). Fixed by making the hash size larger and changeable.
- Introduced key-cache-file-hash-size (default 512) for MyISAM and aria_pagecache_file_hash_size (default 512) for Aria.
- Added new status variable "Feature_delay_key_write" which counts number of tables opened that are using delay_key_write
mysql-test/r/features.result:
Added test of Feature_delay_key_write
mysql-test/r/key_cache.result:
Updated tests as the number of blocks has changed
mysql-test/r/mysqld--help.result:
Updated result
mysql-test/suite/maria/maria3.result:
Updated result
mysql-test/suite/sys_vars/r/key_cache_file_hash_size_basic.result:
Test new variable
mysql-test/suite/sys_vars/t/aria_pagecache_file_hash_size_basic.test:
Test new variable
mysql-test/suite/sys_vars/t/key_cache_file_hash_size_basic.test:
Test new variable
mysql-test/t/features.test:
Added test of Feature_delay_key_write
mysql-test/t/key_cache.test:
Updated tests as the number of blocks has changed
mysys/mf_keycache.c:
Made CHANGED_BLOCKS_HASH dynamic
sql/handler.cc:
Updated call to init_key_cache()
sql/mysqld.cc:
Added "Feature_delay_key_write"
Added support for key-cache-file-hash-size
sql/mysqld.h:
Added support for key-cache-file-hash-size
sql/sql_class.h:
Added feature_files_opened_with_delayed_keys
sql/sys_vars.cc:
Added key_cache_file_hash_size
storage/maria/ha_maria.cc:
Added pagecache_file_hash_size
Added counting of files with delay_key_write
storage/maria/ma_checkpoint.c:
Fixed compiler warning
storage/maria/ma_pagecache.c:
Made PAGECACHE_CHANGED_BLOCKS_HASH into a variable
storage/maria/ma_pagecache.h:
Made PAGECACHE_CHANGED_BLOCKS_HASH into a variable
storage/maria/ma_rt_test.c:
Updated parameters for init_pagecache()
storage/maria/ma_test1.c:
Updated parameters for init_pagecache()
storage/maria/ma_test2.c:
Updated parameters for init_pagecache()
storage/maria/ma_test3.c:
Updated parameters for init_pagecache()
storage/maria/maria_chk.c:
Updated parameters for init_pagecache()
storage/maria/maria_ftdump.c:
Updated parameters for init_pagecache()
storage/maria/maria_pack.c:
Updated parameters for init_pagecache()
storage/maria/maria_read_log.c:
Updated parameters for init_pagecache()
storage/maria/unittest/ma_pagecache_consist.c:
Updated parameters for init_pagecache()
storage/maria/unittest/ma_pagecache_rwconsist.c:
Updated parameters for init_pagecache()
storage/maria/unittest/ma_pagecache_rwconsist2.c:
Updated parameters for init_pagecache()
storage/maria/unittest/ma_pagecache_single.c:
Updated parameters for init_pagecache()
storage/maria/unittest/ma_test_loghandler-t.c:
Updated parameters for init_pagecache()
storage/maria/unittest/ma_test_loghandler_first_lsn-t.c:
Updated parameters for init_pagecache()
storage/maria/unittest/ma_test_loghandler_max_lsn-t.c:
Updated parameters for init_pagecache()
storage/maria/unittest/ma_test_loghandler_multigroup-t.c:
Updated parameters for init_pagecache()
storage/maria/unittest/ma_test_loghandler_multithread-t.c:
Updated parameters for init_pagecache()
storage/maria/unittest/ma_test_loghandler_noflush-t.c:
Updated parameters for init_pagecache()
storage/maria/unittest/ma_test_loghandler_nologs-t.c:
Updated parameters for init_pagecache()
storage/maria/unittest/ma_test_loghandler_pagecache-t.c:
Updated parameters for init_pagecache()
storage/maria/unittest/ma_test_loghandler_purge-t.c:
Updated parameters for init_pagecache()
storage/myisam/ha_myisam.cc:
Added counting of files with delay_key_write
storage/myisam/mi_check.c:
Updated call to init_key_cache()
storage/myisam/mi_test1.c:
Updated call to init_key_cache()
storage/myisam/mi_test2.c:
Updated call to init_key_cache()
storage/myisam/mi_test3.c:
Updated call to init_key_cache()
storage/myisam/mi_test_all.sh:
Fixed broken test
storage/myisam/myisam_ftdump.c:
Updated call to init_key_cache()
storage/myisam/myisamchk.c:
Updated call to init_key_cache()
storage/myisam/myisamlog.c:
Updated call to init_key_cache()
