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Code Activity

MDEV-24738 Improve the InnoDB deadlock checker

Browse Source 
A new configuration parameter innodb_deadlock_report is introduced:
* innodb_deadlock_report=off: Do not report any details of deadlocks.
* innodb_deadlock_report=basic: Report transactions and waiting locks.
* innodb_deadlock_report=full (default): Report also the blocking locks.

The improved deadlock checker will consider all involved transactions
in one loop, even if the deadlock loop includes several transactions.
The theoretical maximum number of transactions that can be involved in
a deadlock is `innodb_page_size` * 8, limited by the persistent data
structures.

Note: Similar to
mysql/mysql-server@3859219875
our deadlock checker will consider at most one blocking transaction
for each waiting transaction. The new field trx->lock.wait_trx be
nullptr if and only if trx->lock.wait_lock is nullptr. Note that
trx->lock.wait_lock->trx == trx (the waiting transaction), while
trx->lock.wait_trx points to one of the transactions whose lock is
conflicting with trx->lock.wait_lock.

Considering only one blocking transaction will greatly simplify
our deadlock checker, but it may also make the deadlock checker
blind to some deadlocks where the deadlock cycle is 'hidden' by
the fact that the registered trx->lock.wait_trx is not actually
waiting for any InnoDB lock, but something else. So, instead of
deadlocks, sometimes lock wait timeout may be reported.

To improve on this, whenever trx->lock.wait_trx is changed, we
will register further 'candidate' transactions in Deadlock::to_check(),
and check for 'revealed' deadlocks as soon as possible, in lock_release()
and innobase_kill_query().

The old DeadlockChecker was holding lock_sys.latch, even though using
lock_sys.wait_mutex should be less contended (and thus preferred)
in the likely case that no deadlock is present.

lock_wait(): Defer the deadlock check to this function, instead of
executing it in lock_rec_enqueue_waiting(), lock_table_enqueue_waiting().

DeadlockChecker: Complete rewrite:
(1) Explicitly keep track of transactions that are being waited for,
in trx->lock.wait_trx, protected by lock_sys.wait_mutex. Previously,
we were painstakingly traversing the lock heaps while blocking
concurrent registration or removal of any locks (even uncontended ones).
(2) Use Brent's cycle-detection algorithm for deadlock detection,
traversing each trx->lock.wait_trx edge at most 2 times.
(3) If a deadlock is detected, release lock_sys.wait_mutex,
acquire LockMutexGuard, re-acquire lock_sys.wait_mutex and re-invoke
find_cycle() to find out whether the deadlock is still present.
(4) Display information on all transactions that are involved in the
deadlock, and choose a victim to be rolled back.

lock_sys.deadlocks: Replaces lock_deadlock_found. Protected by wait_mutex.

Deadlock::find_cycle(): Quickly find a cycle of trx->lock.wait_trx...
using Brent's cycle detection algorithm.

Deadlock::report(): Report a deadlock cycle that was found by
Deadlock::find_cycle(), and choose a victim with the least weight.
Altogether, we may traverse each trx->lock.wait_trx edge up to 5
times (2*find_cycle()+1 time for reporting and choosing the victim).

Deadlock::check_and_resolve(): Find and resolve a deadlock.

lock_wait_rpl_report(): Report the waits-for information to
replication. This used to be executed as part of DeadlockChecker.
Replication must know the waits-for relations even if no deadlocks
are present in InnoDB.

Reviewed by: Vladislav Vaintroub
This commit is contained in:
Marko Mäkelä
2021-02-17 12:43:33 +02:00
parent 3ddb4fddf1
commit c68007d958
14 changed files with 647 additions and 859 deletions
Download Patch File Download Diff File Expand all files Collapse all files

117
mysql-test/suite/sys_vars/r/sysvars_innodb,32bit.rdiff
View File

@@ -9,7 +9,7 @@
VARIABLE_COMMENT Number of InnoDB Adaptive Hash Index Partitions (default 8)
NUMERIC_MIN_VALUE 1
NUMERIC_MAX_VALUE 512
@@ -85,7 +85,7 @@
@@ -73,7 +73,7 @@
SESSION_VALUE NULL
DEFAULT_VALUE 1
VARIABLE_SCOPE GLOBAL
@@ -18,7 +18,7 @@
VARIABLE_COMMENT The AUTOINC lock modes supported by InnoDB: 0 => Old style AUTOINC locking (for backward compatibility); 1 => New style AUTOINC locking; 2 => No AUTOINC locking (unsafe for SBR)
NUMERIC_MIN_VALUE 0
NUMERIC_MAX_VALUE 2
@@ -157,10 +157,10 @@
@@ -97,10 +97,10 @@
SESSION_VALUE NULL
DEFAULT_VALUE 134217728
VARIABLE_SCOPE GLOBAL
@@ -31,7 +31,7 @@
NUMERIC_BLOCK_SIZE 1048576
ENUM_VALUE_LIST NULL
READ_ONLY YES
@@ -193,7 +193,7 @@
@@ -133,7 +133,7 @@
SESSION_VALUE NULL
DEFAULT_VALUE 25
VARIABLE_SCOPE GLOBAL
@@ -40,16 +40,7 @@
VARIABLE_COMMENT Dump only the hottest N% of each buffer pool, defaults to 25
NUMERIC_MIN_VALUE 1
NUMERIC_MAX_VALUE 100
@@ -229,7 +229,7 @@
SESSION_VALUE NULL
DEFAULT_VALUE 0
VARIABLE_SCOPE GLOBAL
-VARIABLE_TYPE BIGINT UNSIGNED
+VARIABLE_TYPE INT UNSIGNED
VARIABLE_COMMENT Deprecated parameter with no effect.
NUMERIC_MIN_VALUE 0
NUMERIC_MAX_VALUE 64
@@ -289,7 +289,7 @@
@@ -217,7 +217,7 @@
SESSION_VALUE NULL
DEFAULT_VALUE 0
VARIABLE_SCOPE GLOBAL
@@ -58,7 +49,7 @@
VARIABLE_COMMENT 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).
NUMERIC_MIN_VALUE 0
NUMERIC_MAX_VALUE 100
@@ -421,7 +421,7 @@
@@ -337,7 +337,7 @@
SESSION_VALUE NULL
DEFAULT_VALUE 5
VARIABLE_SCOPE GLOBAL
@@ -67,7 +58,7 @@
VARIABLE_COMMENT If the compression failure rate of a table is greater than this number more padding is added to the pages to reduce the failures. A value of zero implies no padding
NUMERIC_MIN_VALUE 0
NUMERIC_MAX_VALUE 100
@@ -445,7 +445,7 @@
@@ -361,7 +361,7 @@
SESSION_VALUE NULL
DEFAULT_VALUE 50
VARIABLE_SCOPE GLOBAL
@@ -76,7 +67,7 @@
VARIABLE_COMMENT Percentage of empty space on a data page that can be reserved to make the page compressible.
NUMERIC_MIN_VALUE 0
NUMERIC_MAX_VALUE 75
@@ -745,7 +745,7 @@
@@ -661,7 +661,7 @@
SESSION_VALUE NULL
DEFAULT_VALUE 600
VARIABLE_SCOPE GLOBAL
@@ -85,7 +76,7 @@
VARIABLE_COMMENT Maximum number of seconds that semaphore times out in InnoDB.
NUMERIC_MIN_VALUE 1
NUMERIC_MAX_VALUE 4294967295
@@ -805,7 +805,7 @@
@@ -709,7 +709,7 @@
SESSION_VALUE NULL
DEFAULT_VALUE 30
VARIABLE_SCOPE GLOBAL
@@ -94,7 +85,7 @@
VARIABLE_COMMENT Number of iterations over which the background flushing is averaged.
NUMERIC_MIN_VALUE 1
NUMERIC_MAX_VALUE 1000
@@ -829,7 +829,7 @@
@@ -733,7 +733,7 @@
SESSION_VALUE NULL
DEFAULT_VALUE 1
VARIABLE_SCOPE GLOBAL
@@ -103,7 +94,7 @@
VARIABLE_COMMENT Controls the durability/speed trade-off for commits. Set to 0 (write and flush redo log to disk only once per second), 1 (flush to disk at each commit), 2 (write to log at commit but flush to disk only once per second) or 3 (flush to disk at prepare and at commit, slower and usually redundant). 1 and 3 guarantees that after a crash, committed transactions will not be lost and will be consistent with the binlog and other transactional engines. 2 can get inconsistent and lose transactions if there is a power failure or kernel crash but not if mysqld crashes. 0 has no guarantees in case of crash. 0 and 2 can be faster than 1 or 3.
NUMERIC_MIN_VALUE 0
NUMERIC_MAX_VALUE 3
@@ -853,7 +853,7 @@
@@ -757,7 +757,7 @@
SESSION_VALUE NULL
DEFAULT_VALUE 1
VARIABLE_SCOPE GLOBAL
@@ -112,7 +103,7 @@
VARIABLE_COMMENT Set to 0 (don't flush neighbors from buffer pool), 1 (flush contiguous neighbors from buffer pool) or 2 (flush neighbors from buffer pool), when flushing a block
NUMERIC_MIN_VALUE 0
NUMERIC_MAX_VALUE 2
@@ -901,7 +901,7 @@
@@ -805,7 +805,7 @@
SESSION_VALUE NULL
DEFAULT_VALUE 0
VARIABLE_SCOPE GLOBAL
@@ -121,7 +112,7 @@
VARIABLE_COMMENT Helps to save your data in case the disk image of the database becomes corrupt. Value 5 can return bogus data, and 6 can permanently corrupt data.
NUMERIC_MIN_VALUE 0
NUMERIC_MAX_VALUE 6
@@ -925,7 +925,7 @@
@@ -829,7 +829,7 @@
SESSION_VALUE NULL
DEFAULT_VALUE 8000000
VARIABLE_SCOPE GLOBAL
@@ -130,7 +121,7 @@
VARIABLE_COMMENT InnoDB Fulltext search cache size in bytes
NUMERIC_MIN_VALUE 1600000
NUMERIC_MAX_VALUE 80000000
@@ -961,7 +961,7 @@
@@ -865,7 +865,7 @@
SESSION_VALUE NULL
DEFAULT_VALUE 84
VARIABLE_SCOPE GLOBAL
@@ -139,7 +130,7 @@
VARIABLE_COMMENT InnoDB Fulltext search maximum token size in characters
NUMERIC_MIN_VALUE 10
NUMERIC_MAX_VALUE 84
@@ -973,7 +973,7 @@
@@ -877,7 +877,7 @@
SESSION_VALUE NULL
DEFAULT_VALUE 3
VARIABLE_SCOPE GLOBAL
@@ -148,7 +139,7 @@
VARIABLE_COMMENT InnoDB Fulltext search minimum token size in characters
NUMERIC_MIN_VALUE 0
NUMERIC_MAX_VALUE 16
@@ -985,7 +985,7 @@
@@ -889,7 +889,7 @@
SESSION_VALUE NULL
DEFAULT_VALUE 2000
VARIABLE_SCOPE GLOBAL
@@ -157,7 +148,7 @@
VARIABLE_COMMENT InnoDB Fulltext search number of words to optimize for each optimize table call
NUMERIC_MIN_VALUE 1000
NUMERIC_MAX_VALUE 10000
@@ -997,10 +997,10 @@
@@ -901,10 +901,10 @@
SESSION_VALUE NULL
DEFAULT_VALUE 2000000000
VARIABLE_SCOPE GLOBAL
@@ -170,7 +161,7 @@
NUMERIC_BLOCK_SIZE 0
ENUM_VALUE_LIST NULL
READ_ONLY NO
@@ -1021,7 +1021,7 @@
@@ -925,7 +925,7 @@
SESSION_VALUE NULL
DEFAULT_VALUE 2
VARIABLE_SCOPE GLOBAL
@@ -179,7 +170,7 @@
VARIABLE_COMMENT InnoDB Fulltext search parallel sort degree, will round up to nearest power of 2 number
NUMERIC_MIN_VALUE 1
NUMERIC_MAX_VALUE 16
@@ -1033,7 +1033,7 @@
@@ -937,7 +937,7 @@
SESSION_VALUE NULL
DEFAULT_VALUE 640000000
VARIABLE_SCOPE GLOBAL
@@ -188,7 +179,7 @@
VARIABLE_COMMENT Total memory allocated for InnoDB Fulltext Search cache
NUMERIC_MIN_VALUE 32000000
NUMERIC_MAX_VALUE 1600000000
@@ -1093,22 +1093,22 @@
@@ -985,22 +985,22 @@
SESSION_VALUE NULL
DEFAULT_VALUE 200
VARIABLE_SCOPE GLOBAL
@@ -216,7 +207,7 @@
NUMERIC_BLOCK_SIZE 0
ENUM_VALUE_LIST NULL
READ_ONLY NO
@@ -1153,7 +1153,7 @@
@@ -1021,7 +1021,7 @@
SESSION_VALUE 50
DEFAULT_VALUE 50
VARIABLE_SCOPE SESSION
@@ -225,7 +216,7 @@
VARIABLE_COMMENT Timeout in seconds an InnoDB transaction may wait for a lock before being rolled back. Values above 100000000 disable the timeout.
NUMERIC_MIN_VALUE 0
NUMERIC_MAX_VALUE 1073741824
@@ -1165,10 +1165,10 @@
@@ -1033,10 +1033,10 @@
SESSION_VALUE NULL
DEFAULT_VALUE 16777216
VARIABLE_SCOPE GLOBAL
@@ -238,16 +229,7 @@
NUMERIC_BLOCK_SIZE 1024
ENUM_VALUE_LIST NULL
READ_ONLY YES
@@ -1213,7 +1213,7 @@
SESSION_VALUE NULL
DEFAULT_VALUE 1
VARIABLE_SCOPE GLOBAL
-VARIABLE_TYPE BIGINT UNSIGNED
+VARIABLE_TYPE INT UNSIGNED
VARIABLE_COMMENT Deprecated parameter with no effect.
NUMERIC_MIN_VALUE 1
NUMERIC_MAX_VALUE 100
@@ -1261,7 +1261,7 @@
@@ -1081,7 +1081,7 @@
SESSION_VALUE NULL
DEFAULT_VALUE 8192
VARIABLE_SCOPE GLOBAL
@@ -256,9 +238,9 @@
VARIABLE_COMMENT Redo log write ahead unit size to avoid read-on-write, it should match the OS cache block IO size
NUMERIC_MIN_VALUE 512
NUMERIC_MAX_VALUE 16384
@@ -1273,10 +1273,10 @@
@@ -1093,10 +1093,10 @@
SESSION_VALUE NULL
DEFAULT_VALUE 100
DEFAULT_VALUE 32
VARIABLE_SCOPE GLOBAL
-VARIABLE_TYPE BIGINT UNSIGNED
+VARIABLE_TYPE INT UNSIGNED
@@ -269,9 +251,9 @@
NUMERIC_BLOCK_SIZE 0
ENUM_VALUE_LIST NULL
READ_ONLY NO
@@ -1285,10 +1285,10 @@
@@ -1105,10 +1105,10 @@
SESSION_VALUE NULL
DEFAULT_VALUE 1024
DEFAULT_VALUE 1536
VARIABLE_SCOPE GLOBAL
-VARIABLE_TYPE BIGINT UNSIGNED
+VARIABLE_TYPE INT UNSIGNED
@@ -282,7 +264,7 @@
NUMERIC_BLOCK_SIZE 0
ENUM_VALUE_LIST NULL
READ_ONLY NO
@@ -1333,10 +1333,10 @@
@@ -1153,10 +1153,10 @@
SESSION_VALUE NULL
DEFAULT_VALUE 0
VARIABLE_SCOPE GLOBAL
@@ -295,7 +277,7 @@
NUMERIC_BLOCK_SIZE 0
ENUM_VALUE_LIST NULL
READ_ONLY NO
@@ -1345,7 +1345,7 @@
@@ -1165,7 +1165,7 @@
SESSION_VALUE NULL
DEFAULT_VALUE 0
VARIABLE_SCOPE GLOBAL
@@ -304,7 +286,7 @@
VARIABLE_COMMENT Maximum delay of user threads in micro-seconds
NUMERIC_MIN_VALUE 0
NUMERIC_MAX_VALUE 10000000
@@ -1465,10 +1465,10 @@
@@ -1297,10 +1297,10 @@
SESSION_VALUE NULL
DEFAULT_VALUE 0
VARIABLE_SCOPE GLOBAL
@@ -317,16 +299,7 @@
NUMERIC_BLOCK_SIZE 0
ENUM_VALUE_LIST NULL
READ_ONLY YES
@@ -1489,7 +1489,7 @@
SESSION_VALUE NULL
DEFAULT_VALUE 0
VARIABLE_SCOPE GLOBAL
-VARIABLE_TYPE BIGINT UNSIGNED
+VARIABLE_TYPE INT UNSIGNED
VARIABLE_COMMENT Deprecated parameter with no effect.
NUMERIC_MIN_VALUE 0
NUMERIC_MAX_VALUE 64
@@ -1513,7 +1513,7 @@
@@ -1333,7 +1333,7 @@
SESSION_VALUE NULL
DEFAULT_VALUE 16384
VARIABLE_SCOPE GLOBAL
@@ -335,7 +308,7 @@
VARIABLE_COMMENT Page size to use for all InnoDB tablespaces.
NUMERIC_MIN_VALUE 4096
NUMERIC_MAX_VALUE 65536
@@ -1549,7 +1549,7 @@
@@ -1369,7 +1369,7 @@
SESSION_VALUE NULL
DEFAULT_VALUE 300
VARIABLE_SCOPE GLOBAL
@@ -344,7 +317,7 @@
VARIABLE_COMMENT Number of UNDO log pages to purge in one batch from the history list.
NUMERIC_MIN_VALUE 1
NUMERIC_MAX_VALUE 5000
@@ -1561,7 +1561,7 @@
@@ -1381,7 +1381,7 @@
SESSION_VALUE NULL
DEFAULT_VALUE 128
VARIABLE_SCOPE GLOBAL
@@ -353,7 +326,7 @@
VARIABLE_COMMENT Dictates rate at which UNDO records are purged. Value N means purge rollback segment(s) on every Nth iteration of purge invocation
NUMERIC_MIN_VALUE 1
NUMERIC_MAX_VALUE 128
@@ -1597,7 +1597,7 @@
@@ -1417,7 +1417,7 @@
SESSION_VALUE NULL
DEFAULT_VALUE 56
VARIABLE_SCOPE GLOBAL
@@ -362,7 +335,7 @@
VARIABLE_COMMENT Number of pages that must be accessed sequentially for InnoDB to trigger a readahead.
NUMERIC_MIN_VALUE 0
NUMERIC_MAX_VALUE 64
@@ -1705,7 +1705,7 @@
@@ -1501,7 +1501,7 @@
SESSION_VALUE NULL
DEFAULT_VALUE 1048576
VARIABLE_SCOPE GLOBAL
@@ -371,16 +344,7 @@
VARIABLE_COMMENT Memory buffer size for index creation
NUMERIC_MIN_VALUE 65536
NUMERIC_MAX_VALUE 67108864
@@ -1873,7 +1873,7 @@
SESSION_VALUE NULL
DEFAULT_VALUE 1
VARIABLE_SCOPE GLOBAL
-VARIABLE_TYPE BIGINT UNSIGNED
+VARIABLE_TYPE INT UNSIGNED
VARIABLE_COMMENT Size of the mutex/lock wait array.
NUMERIC_MIN_VALUE 1
NUMERIC_MAX_VALUE 1024
@@ -1897,10 +1897,10 @@
@@ -1669,10 +1669,10 @@
SESSION_VALUE NULL
DEFAULT_VALUE 30
VARIABLE_SCOPE GLOBAL
@@ -393,16 +357,7 @@
NUMERIC_BLOCK_SIZE 0
ENUM_VALUE_LIST NULL
READ_ONLY NO
@@ -2005,7 +2005,7 @@
SESSION_VALUE NULL
DEFAULT_VALUE 128
VARIABLE_SCOPE GLOBAL
-VARIABLE_TYPE BIGINT UNSIGNED
+VARIABLE_TYPE INT UNSIGNED
VARIABLE_COMMENT Deprecated parameter with no effect.
NUMERIC_MIN_VALUE 0
NUMERIC_MAX_VALUE 128
@@ -2029,7 +2029,7 @@
@@ -1765,7 +1765,7 @@
SESSION_VALUE NULL
DEFAULT_VALUE 0
VARIABLE_SCOPE GLOBAL

12
mysql-test/suite/sys_vars/r/sysvars_innodb.result
View File

@@ -417,6 +417,18 @@ NUMERIC_BLOCK_SIZE NULL
ENUM_VALUE_LIST OFF,ON
READ_ONLY NO
COMMAND_LINE_ARGUMENT NONE
VARIABLE_NAME INNODB_DEADLOCK_REPORT
SESSION_VALUE NULL
DEFAULT_VALUE full
VARIABLE_SCOPE GLOBAL
VARIABLE_TYPE ENUM
VARIABLE_COMMENT How to report deadlocks (if innodb_deadlock_detect=ON).
NUMERIC_MIN_VALUE NULL
NUMERIC_MAX_VALUE NULL
NUMERIC_BLOCK_SIZE NULL
ENUM_VALUE_LIST off,basic,full
READ_ONLY NO
COMMAND_LINE_ARGUMENT REQUIRED
VARIABLE_NAME INNODB_DEFAULT_ENCRYPTION_KEY_ID
SESSION_VALUE 1
DEFAULT_VALUE 1