Hi, i currently have the situation that i cannot modify tables/indices beaus of XA transactions which are in progress. mysql://root@localhost:/(none) - 11:37:55 > xa recover; +----------+--------------+--------------+------------------------------------------------------------------+ | formatID | gtrid_length | bqual_length | data | +----------+--------------+--------------+------------------------------------------------------------------+ | 4871251 | 35 | 29 | ^W<89>^B <E8>XF+foo-bar-de05,server,P4837foo-bar-de05,server,P4837,^A | | 4871251 | 35 | 29 | ^N<89>^B <E8>XF+foo-bar-de05,server,P4837foo-bar-de05,server,P4837,^A | +----------+--------------+--------------+------------------------------------------------------------------+ 2 rows in set (0.00 sec) The documentation (https://mariadb.com/kb/en/mariadb/xa-transactions/) suggests that xa transaction can be rolled back by using "xa rollback xid" but it seems that this is not possible because of the non-ascii characters. As you can see in the attached Innodb status, these transactions a active for a log time now and should not be relevant anymore. Naturally restarting the server should not help..... Do you have a suggestion how to prevent, solve or analyze this situation? Regards Marc ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------ mysql://root@localhost:/(none) - 11:34:25 > SHOW ENGINE INNODB STATUS\G *************************** 1. row *************************** Type: InnoDB Name: Status: ===================================== 2016-02-20 11:34:50 7fba401d3700 INNODB MONITOR OUTPUT ===================================== Per second averages calculated from the last 31 seconds ----------------- BACKGROUND THREAD ----------------- srv_master_thread loops: 57 srv_active, 0 srv_shutdown, 171810 srv_idle srv_master_thread log flush and writes: 171823 ---------- SEMAPHORES ---------- OS WAIT ARRAY INFO: reservation count 2076 OS WAIT ARRAY INFO: signal count 2072 Mutex spin waits 339, rounds 174, OS waits 3 RW-shared spins 2133, rounds 63046, OS waits 2069 RW-excl spins 0, rounds 0, OS waits 0 Spin rounds per wait: 0.51 mutex, 29.56 RW-shared, 0.00 RW-excl ------------ TRANSACTIONS ------------ Trx id counter 1969875 Purge done for trx's n:o < 1965495 undo n:o < 0 state: running but idle History list length 316 LIST OF TRANSACTIONS FOR EACH SESSION: ---TRANSACTION 0, not started MySQL thread id 4362, OS thread handle 0x7fba401d3700, query id 23179 localhost root init SHOW ENGINE INNODB STATUS ---TRANSACTION 1969667, not started MySQL thread id 1, OS thread handle 0x7fba41298700, query id 0 Waiting for background binlog tasks ---TRANSACTION 413370, ACTIVE (PREPARED) 172053 sec recovered trx , undo log entries 9 Trx #rec lock waits 0 #table lock waits 0 Trx total rec lock wait time 0 SEC Trx total table lock wait time 0 SEC ---TRANSACTION 413360, ACTIVE (PREPARED) 172053 sec recovered trx , undo log entries 11 Trx #rec lock waits 0 #table lock waits 0 Trx total rec lock wait time 0 SEC Trx total table lock wait time 0 SEC -------- FILE I/O -------- I/O thread 0 state: waiting for completed aio requests (insert buffer thread) I/O thread 1 state: waiting for completed aio requests (log thread) I/O thread 2 state: waiting for completed aio requests (read thread) I/O thread 3 state: waiting for completed aio requests (read thread) I/O thread 4 state: waiting for completed aio requests (read thread) I/O thread 5 state: waiting for completed aio requests (read thread) I/O thread 6 state: waiting for completed aio requests (write thread) I/O thread 7 state: waiting for completed aio requests (write thread) I/O thread 8 state: waiting for completed aio requests (write thread) I/O thread 9 state: waiting for completed aio requests (write thread) 1 row in set (0.00 sec) Regards Marc -- GPG encryption available: 0x670DCBEC/pool.sks-keyservers.net (https://www.256bit.org/keys/mschoechlin.pub.asc)