March 2016 - discuss - lists.mariadb.org

[Maria-discuss] How to rollback XA Transactions
by Marc Schöchlin 04 Mar '16

04 Mar '16

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)

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[Maria-discuss] New Question: Aria System Variables: aria_block_size
by AskMonty KB 03 Mar '16

03 Mar '16

Hello, A new question has been asked in "Aria" by paul.pech_41353. Please answer it at http://mariadb.com/kb/en/aria-system-variables-aria_block_size/ as the person asking the question may not be subscribed to the mailing list. -------------------------------- Hi Are there any guidelines on how to decide what block sizes to use for Aria index pages? We've just switched from MySQL and MyISAM to MariaDB and Aria and noticed a significant drop in performance when full table scans are necessary. In our environment we have 10.000+ databases each with about 20 tables. Each database is usually smaller than 30 - 40 MB (90% of this is contained in roughly 3-4 tables, all other tables usually contain just a couple of rows). Am I correct in assuming that in this case (many comparatively small tables) a small block size (say 2048) could help to improve performance, while for huge tables a larger block size (the default value) is recommended? Any other tips on how to fine tune Aria in particular and MariaDB in general for our use case are highly appreciated. Thanks for a great product and a well written documentation! Yours Paul -------------------------------- To view or answer this question please visit: http://mariadb.com/kb/en/aria-system-variables-aria_block_size/

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[Maria-discuss] New Question: MariaDB removes all users on restart
by AskMonty KB 03 Mar '16

03 Mar '16

Hello, A new question has been asked in "MariaDB FAQ" by andrew_kilburn_g. Please answer it at http://mariadb.com/kb/en/mariadb-removes-all-users-on-restart/ as the person asking the question may not be subscribed to the mailing list. -------------------------------- I am new to MariaDB and have set 3 instances up on 3 different servers. I customised the variables using the MySQL MariaDB client and all was well with the world. However, when coming to restart the machine which the MariaDB databases are currently installed on, it set all the variables back to default values. This is very strange and I'm not sure why this has occurred. After some investigating I found that I can set the variables permanently by changing the My.config file. So this is what I did. My MariaDB instance had 2 users, the original root and the new user which I created. When I restarted the machine after changing the config file by only adding 3 variables, I found that it removed both users and I now cannot connect to MariaDB using any of the users which have been created. I've done this on two machines and now I only have access to one! Why is this? Is this some sort of bug? How am I supposed to get back in? -------------------------------- To view or answer this question please visit: http://mariadb.com/kb/en/mariadb-removes-all-users-on-restart/

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[Maria-discuss] question on semisync
by Qiang Tian 03 Mar '16

03 Mar '16

Hi guys, Do we have enhancement like mysql worklog 6630( http://dev.mysql.com/worklog/task/?id=6630), I did not see it in 10.1 release note.. thanks a lot! Qiang

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[Maria-discuss] Galera crash - [ERROR] Slave SQL: Error 'Can't create table (errno: 150)' on query. Default database: . Query: 'CREATE TABLE'
by Lukas Lehner 02 Mar '16

02 Mar '16

Hi http://dba.stackexchange.com/questions/130307/galera-crash-error-slave-sql-… any idea? howto debug future crashes better? Lukas

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[Maria-discuss] New Question: Error installing AUDIT Plugin in MySQL 5.7
by AskMonty KB 02 Mar '16

02 Mar '16

Hello, A new question has been asked in "MariaDB Community" by sanjaykumar.raghavendra. Please answer it at http://mariadb.com/kb/en/error-installing-audit-plugin-in-mysql-57/ as the person asking the question may not be subscribed to the mailing list. -------------------------------- I downloaded mariadb-10.1.11 for Linux x86-64 and copied the auth_pam.so to plugin directory under MySQL 5.7.10 Community Server home directory. When I attempt to install the plugin I get the following error mysql> install soname 'auth_pam'; ERROR 1064 (42000): You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near 'soname 'auth_pam'' at line 1 Then I tried the following but no luck mysql> install plugin auth_pam_server soname 'auth_pam.so'; ERROR 1127 (HY000): Can't find symbol '_mysql_plugin_interface_version_' in library mysql> install plugin pam soname 'auth_pam.so'; ERROR 1127 (HY000): Can't find symbol '_mysql_plugin_interface_version_' in library Do I need to do anything additional for this to work? -------------------------------- To view or answer this question please visit: http://mariadb.com/kb/en/error-installing-audit-plugin-in-mysql-57/

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