# percona 5.6.14 queries stack up when free buffer count is low **URL:** \ **Category:** Other MySQL® Questions\ **Created:** [December 18, 2013, 10:42am UTC](https://forums.percona.com/t/percona-5-6-14-queries-stack-up-when-free-buffer-count-is-low/3155 "2013-12-18T10:42:33Z")\ **Posts on this page:** 2\ **Page:** 1
**Author:** ![dodizzle](https://sea1.discourse-cdn.com/flex019/user_avatar/forums.percona.com/dodizzle/32/981_2.png) [@dodizzle](https://forums.percona.com/u/dodizzle)\ **Post date:** [December 18, 2013, 10:42am UTC](https://forums.percona.com/t/percona-5-6-14-queries-stack-up-when-free-buffer-count-is-low/3155/1 "2013-12-18T10:42:33Z")
We have a large table which we are attempting to migrate to its own hardware. The table only has 4 columns but has \>3.5 billion rows. The table performs fine running on MySQL 5.6.12 and in a shared environment with several other databases. The problem we are seeing is that when there are plenty of free buffers the queries performs fine, zero slow queries at all. However once the buffer is full or close to full( 1k free buffers) all of the queries become slow and many take several minutes for a simple select on a primary key. We are running on the same hardware for both MySQL 5.6.12 and Percona 5.6.14 80 cores 256GB RAM with a inodb\_buffer\_pool of 200GB and 1.2 TB FusionIO drives. Another confusing part is that when percona does have it buffer pool become full there is little to no disk IO. The table: Table: hearts Create Table: CREATE TABLE `hearts` ( `user_id` int(11) unsigned NOT NULL, `entry_id` int(11) unsigned NOT NULL, `via_user_id` int(11) unsigned DEFAULT NULL, `created_timestamp` int(11) unsigned NOT NULL, PRIMARY KEY (`user_id`,`entry_id`), KEY `index_hearts_on_created_timestamp` (`created_timestamp`), KEY `index_on_user_id_and_created_timestamp` (`user_id`,`created_timestamp`), KEY `index_hearts_on_entry_id_and_via_user_id` (`entry_id`,`via_user_id`) ) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4\_unicode\_ci ROW\_FORMAT=COMPRESSED ---
**Author:** ![przemek](https://sea1.discourse-cdn.com/flex019/user_avatar/forums.percona.com/przemek/32/3_2.png) [@przemek](https://forums.percona.com/u/przemek)\ **Post date:** [December 20, 2013, 9:16am UTC](https://forums.percona.com/t/percona-5-6-14-queries-stack-up-when-free-buffer-count-is-low/3155/2 "2013-12-20T09:16:41Z")
Can you confirm the same problem does not happen when on MySQL 5.6.14 versus Percona Server 5.6.14? Do you use exactly the same configuration and hardware for both MySQL and Percona?