Why are locks appearing in MySQL?

Question

MySQL

I have some database on MySQL under a web project (normal LAMP).
The load is relatively large, but the server is quite productive (64 RAM, 8 cores, MVME).
At some point, on the advice of mysqltuner, I changed the following parameters:

query_cache_type =0
join_buffer_size = 16M
table_open_cache = 4000
innodb_buffer_pool_size = 16G
innodb_buffer_pool_instances = 16

After that, the application periodically began to complain about a long blocking:

SQLSTATE[HY000]: General error: 1205 Lock wait timeout exceeded; try restarting transaction

Can you please tell me which of the specified parameters can cause this behavior?

Answer 1

The parameters are irrelevant. Look for an error in logic. Somewhere there are dead locks. You just don't see it.

Answer 2

There was a case:
https://stackoverflow.com/questions/6000336/how-to...
Doc.
dev.mysql.com/doc/refman/5.5/en/innodb-parameters....