set global innodb_lock_wait_timeout=42; select @@innodb_lock_wait_timeout; @@innodb_lock_wait_timeout 42 set innodb_lock_wait_timeout=1; select @@innodb_lock_wait_timeout; @@innodb_lock_wait_timeout 1 select @@innodb_lock_wait_timeout; @@innodb_lock_wait_timeout 42 set global innodb_lock_wait_timeout=347; select @@innodb_lock_wait_timeout; @@innodb_lock_wait_timeout 42 set innodb_lock_wait_timeout=1; select @@innodb_lock_wait_timeout; @@innodb_lock_wait_timeout 1 select @@innodb_lock_wait_timeout; @@innodb_lock_wait_timeout 347 create table t1(a int primary key)engine=innodb; begin; insert into t1 values(1),(2),(3); select * from t1 for update; commit; a 1 2 3 begin; insert into t1 values(4); select * from t1 for update; commit; ERROR HY000: Lock wait timeout exceeded; try restarting transaction drop table t1; set global innodb_lock_wait_timeout=50;