Hi Guys I am able to reproduce this with Percona Server 5.6.16 & 5.6.17. Was trying to test XtraDB changed page tracking feature which we expect to speed up our Incremental Backups. Even after enabling innodb_track_changed_pages in my.cnf Xtrabackup was scanning the log for changed pages which is obviously slow. Started digging into this & it looks like i cannot select records from information_schema.INNODB_CHANGED_PAGES for some reason. Let me know if need any further information reg this ################################ # 5.6.17-65.0-rel65.0-log ################################ [(root@localhost)]Master_shareddb[(none)]> SHOW VARIABLES LIKE '%version%'; +-------------------------+-----------------------------------------------------------------+ | Variable_name | Value | +-------------------------+-----------------------------------------------------------------+ | innodb_version | 5.6.17-rel65.0 | | protocol_version | 10 | | slave_type_conversions | | | version | 5.6.17-65.0-rel65.0-log | | version_comment | Percona Server with XtraDB (GPL), Release rel65.0, Revision 587 | | version_compile_machine | x86_64 | | version_compile_os | Linux | +-------------------------+-----------------------------------------------------------------+ 7 rows in set (0.01 sec) [(root@localhost)]Master_shareddb[(none)]> SHOW VARIABLES LIKE 'innodb_track_changed_pages'; +----------------------------+-------+ | Variable_name | Value | +----------------------------+-------+ | innodb_track_changed_pages | ON | +----------------------------+-------+ 1 row in set (0.00 sec) [(root@localhost)]Master_shareddb[(none)]> SELECT * FROM information_schema.INNODB_CHANGED_PAGES; ERROR 1012 (HY000): Can't read record in system table [(root@localhost)]Master_shareddb[(none)]> (shareddb)root@Percona-MariaDB-Test-Server:~# grep datadir /etc/my.cnf datadir = /home/XXXXXXX/mysqlshards/shareddb/data (shareddb)root@Percona-MariaDB-Test-Server:~# grep innodb_data_home_dir /etc/my.cnf innodb_data_home_dir = /home/XXXXXXX/mysqlshards/shareddb/innodbdata (shareddb)root@Percona-MariaDB-Test-Server:~# ls -lah /home/XXXXXXX/mysqlshards/shareddb/data total 112K drwxr-xr-x 10 mysql mysql 4.0K 2014-06-10 15:07 . drwxr-xr-x 7 root root 82 2014-06-10 15:02 .. -rw-rw---- 1 mysql mysql 56 2014-06-04 13:31 auto.cnf drwx------ 2 mysql mysql 16K 2014-04-08 08:50 XXXXXXX drwx------ 2 mysql mysql 4.0K 2014-04-08 16:39 XXXXXXX_plugin_blog drwx------ 2 mysql mysql 4.0K 2014-04-08 16:38 XXXXXXX_plugin_ecommerce drwx------ 2 mysql mysql 4.0K 2014-04-08 16:39 XXXXXXX_plugin_menu -rw-rw---- 1 mysql mysql 4 2013-10-09 14:02 BKLIVE-SHAREDMASTER.pid -rw-rw---- 1 mysql mysql 48K 2014-06-10 15:07 ib_modified_log_5_41761187187.xdb -rw-rw---- 1 mysql mysql 106 2014-06-10 15:10 master.info drwx------ 2 mysql mysql 4.0K 2014-06-04 13:32 mysql -rw-r--r-- 1 root root 11 2014-06-04 13:32 mysql_upgrade_info drwx------ 2 mysql mysql 59 2014-02-26 12:14 percona drwx------ 2 mysql mysql 4.0K 2014-06-04 13:32 performance_schema -rw-rw---- 1 mysql mysql 105 2014-06-10 15:10 relay-log.info drwx------ 2 mysql mysql 155 2013-10-07 13:13 slow_query_log (shareddb)root@Percona-MariaDB-Test-Server:~# ls -lah /home/XXXXXXX/mysqlshards/shareddb/innodbdata total 3.1G drwxr-xr-x 2 mysql mysql 4.0K 2014-06-10 15:07 . drwxr-xr-x 7 root root 82 2014-06-10 15:02 .. -rw-rw---- 1 mysql mysql 1.0G 2014-06-10 15:10 ibdata1 -rw-rw---- 1 mysql mysql 1.0G 2014-06-10 15:10 ib_logfile0 -rw-rw---- 1 mysql mysql 1.0G 2014-05-12 13:45 ib_logfile1 -rw-rw---- 1 mysql mysql 4.0K 2014-06-06 10:38 ib_modified_log_1_0.xdb -rw-rw---- 1 mysql mysql 12M 2014-06-06 14:19 ib_modified_log_2_41592797926.xdb -rw-rw---- 1 mysql mysql 6.1M 2014-06-09 15:12 ib_modified_log_3_41729592515.xdb -rw-rw---- 1 mysql mysql 428K 2014-06-10 14:54 ib_modified_log_4_41732445813.xdb -rw-rw---- 1 mysql mysql 20K 2014-06-10 15:02 ib_modified_log_5_41761187187.xdb -rw-rw---- 1 mysql mysql 68K 2014-06-10 15:10 ib_modified_log_6_41761239841.xdb ################################ # 5.6.16-64.2-rel64.2-log ################################ [(root@localhost)]QA_master[(none)]> SHOW VARIABLES LIKE '%version%'; +-------------------------+-----------------------------------------------------------------+ | Variable_name | Value | +-------------------------+-----------------------------------------------------------------+ | innodb_version | 5.6.16-rel64.2 | | protocol_version | 10 | | slave_type_conversions | | | version | 5.6.16-64.2-rel64.2-log | | version_comment | Percona Server with XtraDB (GPL), Release rel64.2, Revision 569 | | version_compile_machine | x86_64 | | version_compile_os | Linux | +-------------------------+-----------------------------------------------------------------+ 7 rows in set (0.00 sec) [(root@localhost)]QA_master[(none)]> SHOW VARIABLES LIKE 'innodb_track_changed_pages'; +----------------------------+-------+ | Variable_name | Value | +----------------------------+-------+ | innodb_track_changed_pages | ON | +----------------------------+-------+ 1 row in set (0.00 sec) [(root@localhost)]QA_master[(none)]> SELECT * FROM information_schema.INNODB_CHANGED_PAGES; ERROR 1012 (HY000): Can't read record in system table [(root@localhost)]QA_master[(none)]> (master)root@CHROOT-QA:~# grep datadir /etc/my.cnf datadir = /home/XXXXXXX/mysqlshards/master/data (master)root@CHROOT-QA:~# grep innodb_data_home_dir /etc/my.cnf innodb_data_home_dir = /home/XXXXXXX/mysqlshards/master/innodbdata (master)root@CHROOT-QA:~# ls -lah /home/XXXXXXX/mysqlshards/master/data/*.xdb -rw-rw---- 1 mysql mysql 32K 2014-05-06 08:03 /home/XXXXXXX/mysqlshards/master/data/ib_modified_log_11_4942444379.xdb -rw-rw---- 1 mysql mysql 101M 2014-05-07 17:09 /home/XXXXXXX/mysqlshards/master/data/ib_modified_log_13_5400695548.xdb -rw-rw---- 1 mysql mysql 101M 2014-05-08 13:28 /home/XXXXXXX/mysqlshards/master/data/ib_modified_log_14_5839440720.xdb -rw-rw---- 1 mysql mysql 101M 2014-05-09 13:39 /home/XXXXXXX/mysqlshards/master/data/ib_modified_log_16_6815221865.xdb -rw-rw---- 1 mysql mysql 101M 2014-05-12 15:17 /home/XXXXXXX/mysqlshards/master/data/ib_modified_log_18_7631481174.xdb -rw-rw---- 1 mysql mysql 7.6M 2014-05-14 08:03 /home/XXXXXXX/mysqlshards/master/data/ib_modified_log_19_8050530268.xdb -rw-rw---- 1 mysql mysql 101M 2014-05-15 14:55 /home/XXXXXXX/mysqlshards/master/data/ib_modified_log_21_8648128613.xdb -rw-rw---- 1 mysql mysql 101M 2014-05-16 14:24 /home/XXXXXXX/mysqlshards/master/data/ib_modified_log_22_9266897493.xdb -rw-rw---- 1 mysql mysql 12M 2014-05-20 08:03 /home/XXXXXXX/mysqlshards/master/data/ib_modified_log_24_10332464624.xdb -rw-rw---- 1 mysql mysql 101M 2014-05-21 18:08 /home/XXXXXXX/mysqlshards/master/data/ib_modified_log_26_11088066295.xdb -rw-rw---- 1 mysql mysql 101M 2014-05-22 16:35 /home/XXXXXXX/mysqlshards/master/data/ib_modified_log_27_11508658747.xdb -rw-rw---- 1 mysql mysql 101M 2014-05-23 14:50 /home/XXXXXXX/mysqlshards/master/data/ib_modified_log_28_11896027376.xdb -rw-rw---- 1 mysql mysql 16K 2014-05-27 08:04 /home/XXXXXXX/mysqlshards/master/data/ib_modified_log_29_12601000835.xdb -rw-rw---- 1 mysql mysql 47M 2014-05-29 08:04 /home/XXXXXXX/mysqlshards/master/data/ib_modified_log_30_12629147264.xdb -rw-rw---- 1 mysql mysql 101M 2014-05-30 16:40 /home/XXXXXXX/mysqlshards/master/data/ib_modified_log_31_12924723142.xdb -rw-rw---- 1 mysql mysql 101M 2014-06-02 14:34 /home/XXXXXXX/mysqlshards/master/data/ib_modified_log_32_13318336682.xdb -rw-rw---- 1 mysql mysql 4.2M 2014-04-17 08:08 /home/XXXXXXX/mysqlshards/master/data/ib_modified_log_3_2991844810.xdb -rw-rw---- 1 mysql mysql 101M 2014-06-03 13:19 /home/XXXXXXX/mysqlshards/master/data/ib_modified_log_34_14144397863.xdb -rw-rw---- 1 mysql mysql 101M 2014-06-04 13:21 /home/XXXXXXX/mysqlshards/master/data/ib_modified_log_35_14596365285.xdb -rw-rw---- 1 mysql mysql 101M 2014-06-05 13:15 /home/XXXXXXX/mysqlshards/master/data/ib_modified_log_37_15629838787.xdb -rw-rw---- 1 mysql mysql 101M 2014-06-06 13:32 /home/XXXXXXX/mysqlshards/master/data/ib_modified_log_38_16060275889.xdb -rw-rw---- 1 mysql mysql 101M 2014-06-09 14:34 /home/XXXXXXX/mysqlshards/master/data/ib_modified_log_39_16803050980.xdb -rw-rw---- 1 mysql mysql 101M 2014-06-10 13:39 /home/XXXXXXX/mysqlshards/master/data/ib_modified_log_40_17183153859.xdb -rw-rw---- 1 mysql mysql 624K 2014-04-21 08:07 /home/XXXXXXX/mysqlshards/master/data/ib_modified_log_4_3316478840.xdb -rw-rw---- 1 mysql mysql 65M 2014-04-23 08:07 /home/XXXXXXX/mysqlshards/master/data/ib_modified_log_5_3326225993.xdb -rw-rw---- 1 mysql mysql 13M 2014-04-25 08:10 /home/XXXXXXX/mysqlshards/master/data/ib_modified_log_6_3583387757.xdb -rw-rw---- 1 mysql mysql 101M 2014-04-28 17:49 /home/XXXXXXX/mysqlshards/master/data/ib_modified_log_7_3729662427.xdb -rw-rw---- 1 mysql mysql 21M 2014-04-30 08:09 /home/XXXXXXX/mysqlshards/master/data/ib_modified_log_8_4235868871.xdb -rw-rw---- 1 mysql mysql 23M 2014-05-02 08:09 /home/XXXXXXX/mysqlshards/master/data/ib_modified_log_9_4409961063.xdb (master)root@CHROOT-QA:~# ls -lah /home/XXXXXXX/mysqlshards/master/innodbdata total 5.2G drwxr-xr-x 2 mysql mysql 4.0K 2014-06-10 13:39 . drwxr-xr-x 7 XXXXXXX XXXXXXX 122 2014-04-09 10:48 .. -rw-rw---- 1 mysql mysql 1.0G 2014-06-10 15:24 ibdata1 -rw-rw---- 1 mysql mysql 1.0G 2014-06-10 15:24 ib_logfile0 -rw-rw---- 1 mysql mysql 1.0G 2014-06-09 14:33 ib_logfile1 -rw-rw---- 1 mysql mysql 101M 2014-05-02 16:04 ib_modified_log_10_4574229937.xdb -rw-rw---- 1 mysql mysql 101M 2014-04-09 17:04 ib_modified_log_1_0.xdb -rw-rw---- 1 mysql mysql 22M 2014-05-02 20:00 ib_modified_log_11_4942444379.xdb -rw-rw---- 1 mysql mysql 101M 2014-05-06 18:16 ib_modified_log_12_5020631946.xdb -rw-rw---- 1 mysql mysql 23M 2014-05-06 20:00 ib_modified_log_13_5400695548.xdb -rw-rw---- 1 mysql mysql 60M 2014-05-07 20:00 ib_modified_log_14_5839440720.xdb -rw-rw---- 1 mysql mysql 101M 2014-05-08 17:49 ib_modified_log_15_6450364940.xdb -rw-rw---- 1 mysql mysql 22M 2014-05-08 20:00 ib_modified_log_16_6815221865.xdb -rw-rw---- 1 mysql mysql 101M 2014-05-09 18:58 ib_modified_log_17_7269044778.xdb -rw-rw---- 1 mysql mysql 19M 2014-05-09 20:00 ib_modified_log_18_7631481174.xdb -rw-rw---- 1 mysql mysql 61M 2014-05-12 20:00 ib_modified_log_19_8050530268.xdb -rw-rw---- 1 mysql mysql 101M 2014-05-14 17:55 ib_modified_log_20_8266360233.xdb -rw-rw---- 1 mysql mysql 60M 2014-05-14 20:00 ib_modified_log_21_8648128613.xdb -rw-rw---- 1 mysql mysql 101M 2014-04-10 17:03 ib_modified_log_2_2600704330.xdb -rw-rw---- 1 mysql mysql 91M 2014-05-15 20:00 ib_modified_log_22_9266897493.xdb -rw-rw---- 1 mysql mysql 101M 2014-05-16 17:34 ib_modified_log_23_9948474550.xdb -rw-rw---- 1 mysql mysql 84M 2014-05-16 20:00 ib_modified_log_24_10332464624.xdb -rw-rw---- 1 mysql mysql 101M 2014-05-20 18:05 ib_modified_log_25_10672405932.xdb -rw-rw---- 1 mysql mysql 9.4M 2014-05-20 19:41 ib_modified_log_26_11088066295.xdb -rw-rw---- 1 mysql mysql 14M 2014-05-21 20:00 ib_modified_log_27_11508658747.xdb -rw-rw---- 1 mysql mysql 90M 2014-05-22 20:00 ib_modified_log_28_11896027376.xdb -rw-rw---- 1 mysql mysql 9.7M 2014-05-23 20:00 ib_modified_log_29_12601000835.xdb -rw-rw---- 1 mysql mysql 48M 2014-05-27 20:00 ib_modified_log_30_12629147264.xdb -rw-rw---- 1 mysql mysql 9.4M 2014-05-29 20:00 ib_modified_log_31_12924723142.xdb -rw-rw---- 1 mysql mysql 10M 2014-05-30 20:00 ib_modified_log_32_13318336682.xdb -rw-rw---- 1 mysql mysql 95M 2014-04-15 20:00 ib_modified_log_3_2991844810.xdb -rw-rw---- 1 mysql mysql 101M 2014-06-02 17:37 ib_modified_log_33_13719519672.xdb -rw-rw---- 1 mysql mysql 8.3M 2014-06-02 20:00 ib_modified_log_34_14144397863.xdb -rw-rw---- 1 mysql mysql 95M 2014-06-03 20:00 ib_modified_log_35_14596365285.xdb -rw-rw---- 1 mysql mysql 101M 2014-06-04 19:32 ib_modified_log_36_15290974029.xdb -rw-rw---- 1 mysql mysql 22M 2014-06-04 20:00 ib_modified_log_37_15629838787.xdb -rw-rw---- 1 mysql mysql 97M 2014-06-05 20:00 ib_modified_log_38_16060275889.xdb -rw-rw---- 1 mysql mysql 11M 2014-06-06 20:01 ib_modified_log_39_16803050980.xdb -rw-rw---- 1 mysql mysql 30M 2014-06-09 20:01 ib_modified_log_40_17183153859.xdb -rw-rw---- 1 mysql mysql 5.1M 2014-06-10 15:24 ib_modified_log_41_17671006976.xdb -rw-rw---- 1 mysql mysql 3.9M 2014-04-17 20:00 ib_modified_log_4_3316478840.xdb -rw-rw---- 1 mysql mysql 648K 2014-04-21 20:00 ib_modified_log_5_3326225993.xdb -rw-rw---- 1 mysql mysql 34M 2014-04-23 20:00 ib_modified_log_6_3583387757.xdb -rw-rw---- 1 mysql mysql 28M 2014-04-25 20:00 ib_modified_log_7_3729662427.xdb -rw-rw---- 1 mysql mysql 28M 2014-04-28 20:00 ib_modified_log_8_4235868871.xdb -rw-rw---- 1 mysql mysql 27M 2014-04-30 20:00 ib_modified_log_9_4409961063.xdb