InnoDB row level locks without SELECTs? I have several (>30) MySQL clients inserting into InnoDB tables concurrently. I keep encountering lock wait timeouts and can't figure out why. Here is the situation:

Each client runs the following transactions repeatedly:

Start transaction
Insert one row into table A
for i = 1 to 22
  Do some time-consuming calculation (30 sec)
  Insert results into table B
end
Commit transaction


The lock wait timeouts happen when inserting into table A. Table B's primary key is the same as table A's augmented by another field. Table B has a foreign key into table A.

There are no SELECTs anywhere. No row is inserted twice. Transaction isolation level is REPEATABLE_READ.

SHOW ENGINE INNODB STATUS shows up to 36 row-level locks for some active transactions.

I do not understand why there are any locks. Can anyone give me some hints as to what's going on?
MySQL is taking too much of the innodb buffer pool size for your table locking.

Insert innodb_buffer_pool_size=2g in my.cnf file, which is most probably in /etc/mysql/