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@xaprb /locks.sql Secret
Created Dec 14, 2013

INFORMATION_SCHEMA queries to show InnoDB locks
SELECT r.trx_id AS waiting_trx_id, r.trx_mysql_thread_id AS waiting_thread,
TIMESTAMPDIFF(SECOND, r.trx_wait_started, CURRENT_TIMESTAMP) AS wait_time,
r.trx_query AS waiting_query,
l.lock_table AS waiting_table_lock,
b.trx_id AS blocking_trx_id, b.trx_mysql_thread_id AS blocking_thread,
SUBSTRING(p.host, 1, INSTR(p.host, ':') - 1) AS blocking_host,
SUBSTRING(p.host, INSTR(p.host, ':') +1) AS blocking_port,
IF(p.command = "Sleep", p.time, 0) AS idle_in_trx,
b.trx_query AS blocking_query
FROM INFORMATION_SCHEMA.INNODB_LOCK_WAITS AS w
INNER JOIN INFORMATION_SCHEMA.INNODB_TRX AS b ON b.trx_id = w.blocking_trx_id
INNER JOIN INFORMATION_SCHEMA.INNODB_TRX AS r ON r.trx_id = w.requesting_trx_id
INNER JOIN INFORMATION_SCHEMA.INNODB_LOCKS AS l ON w.requested_lock_id = l.lock_id
LEFT JOIN INFORMATION_SCHEMA.PROCESSLIST AS p ON p.id = b.trx_mysql_thread_id
ORDER BY wait_time DESC\G
SELECT CONCAT('thread ', b.trx_mysql_thread_id, ' from ', p.host) AS who_blocks,
IF(p.command = "Sleep", p.time, 0) AS idle_in_trx,
MAX(TIMESTAMPDIFF(SECOND, r.trx_wait_started, CURRENT_TIMESTAMP)) AS max_wait_time,
COUNT(*) AS num_waiters
FROM INFORMATION_SCHEMA.INNODB_LOCK_WAITS AS w
INNER JOIN INFORMATION_SCHEMA.INNODB_TRX AS b ON b.trx_id = w.blocking_trx_id
INNER JOIN INFORMATION_SCHEMA.INNODB_TRX AS r ON r.trx_id = w.requesting_trx_id
LEFT JOIN INFORMATION_SCHEMA.PROCESSLIST AS p ON p.id = b.trx_mysql_thread_id
GROUP BY who_blocks ORDER BY num_waiters DESC\G
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