# About deadlock of FLUSH TABLES WITH READ LOCK in xtrabackup **URL:** \ **Category:** Percona XtraBackup\ **Created:** [April 3, 2018, 3:17am UTC](https://forums.percona.com/t/about-deadlock-of-flush-tables-with-read-lock-in-xtrabackup/6277 "2018-04-03T03:17:09Z")\ **Posts on this page:** 7\ **Page:** 1
**Author:** ![Yuji\_Fujihara](https://avatars.discourse-cdn.com/v4/letter/y/13edae/32.png) [@Yuji\_Fujihara](https://forums.percona.com/u/Yuji_Fujihara)\ **Post date:** [April 3, 2018, 3:17am UTC](https://forums.percona.com/t/about-deadlock-of-flush-tables-with-read-lock-in-xtrabackup/6277/1 "2018-04-03T03:17:09Z")
I am using Xtrabackup. percona-xtrabackup-24-2.4.8-1.el6.x86\_64 Is there a backup method that does not use FLUSH TABLES WITH READ LOCK ? I am using slave and multithread slave. A deadlock bug may occur. [url][MySQL Bugs: #87489: MTS ordered commit may cause deadlock with "FLUSH TABLES WITH READ LOCK"of slave](https://bugs.mysql.com/bug.php?id=87489%5B/url%5D) Please tell me the way to avoid this bug. ---
**Author:** ![Yuji\_Fujihara](https://avatars.discourse-cdn.com/v4/letter/y/13edae/32.png) [@Yuji\_Fujihara](https://forums.percona.com/u/Yuji_Fujihara)\ **Post date:** [April 3, 2018, 6:39pm UTC](https://forums.percona.com/t/about-deadlock-of-flush-tables-with-read-lock-in-xtrabackup/6277/2 "2018-04-03T18:39:33Z")
Xtrabackup’s --backup-locks is enabled by default. Do not lock Innodb’s DML? –ftwrl-wait-timeout=SECONDS xtrabackup will automatically use Backup Locks as a lightweight alternative to FLUSH TABLES WITH READ LOCK to copy non-InnoDB data to avoid blocking DML queries that modify InnoDB tables. ---
**Author:** ![Yuji\_Fujihara](https://avatars.discourse-cdn.com/v4/letter/y/13edae/32.png) [@Yuji\_Fujihara](https://forums.percona.com/u/Yuji_Fujihara)\ **Post date:** [April 3, 2018, 7:22pm UTC](https://forums.percona.com/t/about-deadlock-of-flush-tables-with-read-lock-in-xtrabackup/6277/3 "2018-04-03T19:22:09Z")
I am using MySQL Community Edition. ---
**Author:** ![lorraine.pocklington](https://sea1.discourse-cdn.com/flex019/user_avatar/forums.percona.com/lorraine.pocklington/32/37_2.png) [@lorraine.pocklington](https://forums.percona.com/u/lorraine.pocklington)\ **Post date:** [April 4, 2018, 3:41am UTC](https://forums.percona.com/t/about-deadlock-of-flush-tables-with-read-lock-in-xtrabackup/6277/4 "2018-04-04T03:41:37Z")
Hello there can I just check - are you actually encountering this bug or are you just trying to make sure that you don’t encounter it in the future? Thanks! ---
**Author:** ![Yuji\_Fujihara](https://avatars.discourse-cdn.com/v4/letter/y/13edae/32.png) [@Yuji\_Fujihara](https://forums.percona.com/u/Yuji_Fujihara)\ **Post date:** [April 4, 2018, 3:55am UTC](https://forums.percona.com/t/about-deadlock-of-flush-tables-with-read-lock-in-xtrabackup/6277/5 "2018-04-04T03:55:57Z")
Hello. I encountered this bug with mysqldump. I am checking if I encounter the same bug with xtrabackup. However, I think that using - safe - slave - backup option will not encounter. is it right? ---
**Author:** ![Michael\_Coburn](https://sea1.discourse-cdn.com/flex019/user_avatar/forums.percona.com/michael_coburn/32/18_2.png) [@Michael\_Coburn](https://forums.percona.com/u/Michael_Coburn)\ **Post date:** [April 9, 2018, 10:55am UTC](https://forums.percona.com/t/about-deadlock-of-flush-tables-with-read-lock-in-xtrabackup/6277/6 "2018-04-09T10:55:26Z")
Hi [Yuji Fujihara](https://percona.vanillacommunities.com/profile/x/x/37851) If you want to avoid locks then you should examine --no-lock [url][https://www.percona.com/doc/percona-xtrabackup/LATEST/innobackupex/innobackupex\_option\_reference.html#cmdoption-innobackupex-no-lock[/url]](https://www.percona.com/doc/percona-xtrabackup/LATEST/innobackupex/innobackupex_option_reference.html#cmdoption-innobackupex-no-lock%5B/url%5D) But likely what you should work towards is --safe-slave-backup [url][https://www.percona.com/doc/percona-xtrabackup/LATEST/innobackupex/innobackupex\_option\_reference.html#cmdoption-innobackupex-safe-slave-backup[/url]](https://www.percona.com/doc/percona-xtrabackup/LATEST/innobackupex/innobackupex_option_reference.html#cmdoption-innobackupex-safe-slave-backup%5B/url%5D) ---
**Author:** ![Yuji\_Fujihara](https://avatars.discourse-cdn.com/v4/letter/y/13edae/32.png) [@Yuji\_Fujihara](https://forums.percona.com/u/Yuji_Fujihara)\ **Post date:** [April 9, 2018, 6:13pm UTC](https://forums.percona.com/t/about-deadlock-of-flush-tables-with-read-lock-in-xtrabackup/6277/7 "2018-04-09T18:13:12Z")
Thanks you!