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[Maria-discuss] New Question: Is Aria a good choice in environments where power will often fail?
by AskMonty KB 08 Mar '16

08 Mar '16

Hello, A new question has been asked in "Aria" by thomas_gawehn. Please answer it at http://mariadb.com/kb/en/is-aria-a-good-choice-in-environments-where-power-… as the person asking the question may not be subscribed to the mailing list. -------------------------------- Hi all, the Aria storage engine is described to be "crash safe". Would this mean that Aria is a good choice in production environments where the system power is expected to fail very often? Think about small embedded systems which are run without UPS? What will happen when power fails right whilst a record being updated or inserted and the corresponding I/O is right written to the disk at that moment? Would the database then come up corrupt after the next boot, with manuel assistance being neccessary -or- will the database be fine in general, and only the last record / the last change / last operation vanishes? Always presumed, the LOCK TABLES command is sent directly after each data manipulation command. What about possible operating system or hard disk "write behand" caches? Thanks and best regards Thomas -------------------------------- To view or answer this question please visit: http://mariadb.com/kb/en/is-aria-a-good-choice-in-environments-where-power-…

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[Maria-discuss] New Question: MariaDB SSL connection with Connector/J Setup help
by AskMonty KB 08 Mar '16

08 Mar '16

Hello, A new question has been asked in "SSL Connections" by og_116262525349832924122. Please answer it at http://mariadb.com/kb/en/mariadb-ssl-connection-with-connectorj-setup-help/ as the person asking the question may not be subscribed to the mailing list. -------------------------------- I just installed MariaDB 10.1.11 on Centos 7 and enabled SSL connections. I created the root CA, Server Cert/Key, & Client Cert/Key as spelled out in the instructions from this link http://xmodulo.com/enable-ssl-mysql-server-client.html (used -sha256 instead of -sha1) I added the variables in the [mysqld] section of the server.cnf file and restarted MariaDB I created a user and granted them privilages with a "require x509" suffix. I have 2 users created (nossluser, ssluser) grant all on *.* to nossluser; grant all on *.* to ssluser require X509; I can login from the command line using MySQL without any problems MySQL -u nossluser -p <--- works fine with the user that has no ssl requirement MySQL -u ssluser -p --ssl-cert client-cert.pem --ssl-key client-key.pem --ssl-ca ca-cert.pem <-- this works fine I can also connect from a remote client using MySQL workbench using the same ca-cert.pem, client-cert.pem, client-key.pem as I used on the command line. My problem is when I try to create a java client connection using the Mariadb connector/j I have tried issuing the connection using the useSSL=true, requireSSL=true, serverSslCert=server-cert.pem but it does not work. I get the: "Could not connect: Access denied for user 'ssluser'@192.168.1.9' (using password: YES)" error message I also enabled java.net.debug and I get a message in the log that says: "Warning:no suitable certificate found - continuing without client authentication" Now if I change the user to "require ssl" instead of "require x509" The connection works, but I still see the java net debug warning no suitable certificate found which I assume means that the SSL connection did not work but it allowed the connection anyway. Any Ideas on the correct connection settings for the connector/j Thanks, Willie -------------------------------- To view or answer this question please visit: http://mariadb.com/kb/en/mariadb-ssl-connection-with-connectorj-setup-help/

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[Maria-discuss] New Question: CentOS v6 glibc 2.12 default but Tokudb need 2.14
by AskMonty KB 07 Mar '16

07 Mar '16

Hello, A new question has been asked in "TokuDB" by yngve.eriksson_39408. Please answer it at http://mariadb.com/kb/en/centos-v6-glibc-212-default-but-tokudb-need-214/ as the person asking the question may not be subscribed to the mailing list. -------------------------------- What is the best way to install glibc 2.14 ? so many tell me not to mess with glibc version or CentosOS is unstable ..... is it included in CentOS 7 ? is that the way to go ? or how do I install glibc 2.14 ? Where do I get it from .... yum -UHv xxxxx_glibc-2.14.rpm ??? -------------------------------- To view or answer this question please visit: http://mariadb.com/kb/en/centos-v6-glibc-212-default-but-tokudb-need-214/

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[Maria-discuss] New Question: Problem with the Galera wsrep_sst_method xtrabackup-v2
by AskMonty KB 04 Mar '16

04 Mar '16

Hello, A new question has been asked in "MariaDB Community" by aferrett. Please answer it at http://mariadb.com/kb/en/problem-with-the-galera-wsrep_sst_method-xtrabacku… as the person asking the question may not be subscribed to the mailing list. -------------------------------- We are trying to create a Galera cluster. We have our first node running. We want to use xtrabackup to initialize the 2nd cluster node. We are getting error: 2016-03-04 22:56:20 140441685063424 [ERROR] WSREP: Failed to read 'ready <addr>' from: wsrep_sst_xtrabackup-v2 --role 'joiner' --address '130.9.221.48' --datadir '//opt/app/mysql/data/' --parent '28544' --binlog '//opt/app/mysql/binlogs/mysql-bin' Read: '(null)' 2016-03-04 22:56:20 140441685063424 [ERROR] WSREP: Process completed with error: wsrep_sst_xtrabackup-v2 --role 'joiner' --address '130.9.221.48' --datadir '//opt/app/mysql/data/' --parent '28544' --binlog '//opt/app/mysql/binlogs/mysql-bin' : 1 (Operation not permitted) 2016-03-04 22:56:20 140441697642240 [ERROR] WSREP: Failed to prepare for 'xtrabackup-v2' SST. Unrecoverable. 2016-03-04 22:56:20 140441697642240 [ERROR] Aborting -------------------------------- To view or answer this question please visit: http://mariadb.com/kb/en/problem-with-the-galera-wsrep_sst_method-xtrabacku…

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[Maria-discuss] New Question: MariaDB Connector/J
by AskMonty KB 04 Mar '16

04 Mar '16

Hello, A new question has been asked in "MariaDB FAQ" by xviakoh_g. Please answer it at http://mariadb.com/kb/en/mariadb-faq-mariadb-connectorj/ as the person asking the question may not be subscribed to the mailing list. -------------------------------- Hi, We are using MariaDB Connector/J against our production AWS Aurora RDS and noticed that default socketTimeout is set to 10 seconds against Aurora. Is there a reason behind this default value? Is there any implication of increasing timeout that I should be aware? We do have transaction layer that times out at 60 seconds. So was thinking to up it to match our higher layer timeout. any advice is greatly appreciated. -------------------------------- To view or answer this question please visit: http://mariadb.com/kb/en/mariadb-faq-mariadb-connectorj/

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[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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