- Make accelerated checksum available to InnoDB and XtraDB.
- Fall back to slice-by-eight if not available. The mode used is printed on startup.
- Will only build on POWER systems at the moment until CMakeLists are modified
to only add the crc32_power8/ files when building on POWER.
running MySQL-5.7 unittest/gunit/innodb/ut0crc32-t
Before:
1..2
Using software crc32 implementation, CPU is little-endian
ok 1
Using software crc32 implementation, CPU is little-endian
normal CRC32: real 0.148006 sec
normal CRC32: user 0.148000 sec
normal CRC32: sys 0.000000 sec
big endian CRC32: real 0.144293 sec
big endian CRC32: user 0.144000 sec
big endian CRC32: sys 0.000000 sec
ok 2
After:
1..2
Using POWER8 crc32 implementation, CPU is little-endian
ok 1
Using POWER8 crc32 implementation, CPU is little-endian
normal CRC32: real 0.008097 sec
normal CRC32: user 0.008000 sec
normal CRC32: sys 0.000000 sec
big endian CRC32: real 0.147043 sec
big endian CRC32: user 0.144000 sec
big endian CRC32: sys 0.000000 sec
ok 2
Author CRC32 ASM code: Anton Blanchard <anton@au.ibm.com>
ref: https://github.com/antonblanchard/crc32-vpmsum
Signed-off-by: Daniel Black <daniel.black@au.ibm.com>
WL#6504 InnoDB buffer pool dump/load enchantments
This patch consists of two parts:
1. Dump only the hottest N% of the buffer pool(s)
2. Prevent hogging the server duing BP load
From MySQL - commit b409342c43ce2edb68807100a77001367c7e6b8e
Analysis: Current implementation will write and read at least one block
(sort_buffer_size bytes) from disk / index even if that block does not
contain any records.
Fix: Avoid writing / reading empty blocks to temporary files (disk).
Added new dynamic configuration variable innodb_buf_dump_status_frequency
to configure how often buffer pool dump status is printed in the logs.
A number between [0, 100] that tells how oftern buffer pool dump status
in percentages should be printed. E.g. 10 means that buffer pool dump
status is printed when every 10% of number of buffer pool pages are
dumped. Default is 0 (only start and end status is printed).
Analysis: Problem was that we did create crypt data for encrypted table but
this new crypt data was not written to page 0. Instead a default crypt data
was written to page 0 at table creation.
Fixed by explicitly writing new crypt data to page 0 after successfull
table creation.
Step 2:
-- Introduce temporal memory array to buffer pool where to allocate
temporary memory for encryption/compression
-- Rename PAGE_ENCRYPTION -> ENCRYPTION
-- Rename PAGE_ENCRYPTION_KEY -> ENCRYPTION_KEY
-- Rename innodb_default_page_encryption_key -> innodb_default_encryption_key
-- Allow enable/disable encryption for tables by changing
ENCRYPTION to enum having values DEFAULT, ON, OFF
-- In create table store crypt_data if ENCRYPTION is ON or OFF
-- Do not crypt tablespaces having ENCRYPTION=OFF
-- Store encryption mode to crypt_data and redo-log
Step 1:
-- Remove page encryption from dictionary (per table
encryption will be handled by storing crypt_data to page 0)
-- Remove encryption/compression from os0file and all functions
before that (compression will be added to buf0buf.cc)
-- Use same CRYPT_SCHEME_1 for all encryption methods
-- Do some code cleanups to confort InnoDB coding style
MDEV-7399: Add support for INFORMATION_SCHEMA.INNODB_MUTEXES
MDEV-7618: Improve semaphore instrumentation
Introduced two new information schema tables to monitor mutex waits
and semaphore waits. Added a new configuration variable
innodb_intrument_semaphores to add thread_id, file name and
line of current holder of mutex/rw_lock.
in file buf0mtflu.cc line 439
Analysis: At shutdown multi-threaded flush sends a exit work
items to all mtflush threads. We wait until the work queue is
empty. However, as we did not hold the mutex, some other thread
could also put work-items to work queue.
Fix: Take mutex before adding exit work items to work queue and
wait until all work-items are really processed. Release
mutex after we have marked that multi-threaded flush is not
anymore active.
Fix test failure on innodb_bug12902967 caused by unnecessary
info output on xtradb/buf/buf0mtflush.cc.
Do not try to enable atomic writes if the file type
is not OS_DATA_FILE. Atomic writes are unnecessary
for log files. If we try to enable atomic writes
to log writes that are stored to media supporting
atomic writes we will end up problems later.
Analysis: For some reason actual thread handle is not
returned on Windows instead lpThreadId was returned and
thread handle was closed after thread create. Later
CloseHandle was called for recv_writer_thread_handle
and psort_info->thread_hdl.
Fix: Return thread handle from os_thread_create()
also on Windows and store these thread handles also
in srv0start.cc so that they can be later closed.
Use traditional statistics estimation by default (innodb-stats-traditional=true).
There could be performance regression for customers if there is a lot of
open table operations.
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))
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).
