Hi, I have an InnoDB table for visitors' counting, which has perfectly worked for several years, but it failed twice yesterday, may be cause of the increase of visitors Without apparent reason, this table locked, with hundreds of DELETE an REPLACE INTO queries (+500) with "updating" or "cleaning up" status. (I've no more the copy of the processlist...) This table contains few entries, between 500 and 1500, so the updating queries are usualy very fast and don't lock. I don't know where I must search to find the cause of this problem and resolve it definitively. But I guess this could give you a better vision of the problem : mysql> show global status like "%innodb_row_lock%"; +-------------------------------+-----------+ | Variable_name | Value | +-------------------------------+-----------+ | Innodb_row_lock_current_waits | 0 | | Innodb_row_lock_time | 132004175 | | Innodb_row_lock_time_avg | 10521 | | Innodb_row_lock_time_max | 59373 | | Innodb_row_lock_waits | 12546 | +-------------------------------+-----------+ 5 rows in set (0.00 sec) Sorry for my poor english, and thanks for your help ;-)