I'm currently unable to insert rows concurrently in an XtraDB table on Percona Server 5.1.54. I had the same problem with a similar version of MySQL. My table definition is as follows.
CREATE TABLE `test` ( `a` int(11) NOT NULL DEFAULT '0', `b` int(11) DEFAULT NULL, PRIMARY KEY (`a`) ) ENGINE=MyISAM
If in on one connection, I execute something like
INSERT INTO test VALUES (0, sleep(60)) and in a second process,
INSERT INTO test VALUES (1, 0), the second insert will wait for the first to complete. Note that
innodb_table_locks is off. Is there something I'm missing, or is this just not possible?
As Randy points out below, I created a MyISAM table during testing and then assumed that concurrent inserts weren't possible for my other tables (which are InnoDB). I actually don't have a problem with InnoDB tables.