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[Maria-discuss] We are participating in Google Summer of Code 2014
by Colin Charles 25 Feb '14

25 Feb '14

Hi, It is with great pleasure that I can inform you that we have been accepted as an organisation to participate in Google Summer of Code 2014! It would be great to see more ideas pop up here: https://mariadb.com/kb/en/google-summer-of-code-2014/ More mentors are always wanted! I presume we will see a lot more student discussions here as well. If you have any questions that aren't answered on the lists, please send me a personal note Here's to more features & contributors in 2014. cheers, -colin -- Colin Charles, Chief Evangelist MariaDB | t: +6-012-204-3201 | Skype: colincharles

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[Maria-discuss] InnoDB: Assertion failure in thread 139652707100416 in file buf0buf.c line 4172
by Reindl Harald 21 Feb '14

21 Feb '14

Hi after chnage to MariaDB i faced tonight that the third time on one of our dbmail-replication-slaves while that never happened with MySQL over years :-( 140221 3:19:50 InnoDB: Assertion failure in thread 139652707100416 in file buf0buf.c line 4172 InnoDB: We intentionally generate a memory trap. InnoDB: Submit a detailed bug report to http://bugs.mysql.com. InnoDB: If you get repeated assertion failures or crashes, even InnoDB: immediately after the mysqld startup, there may be InnoDB: corruption in the InnoDB tablespace. Please refer to InnoDB: http://dev.mysql.com/doc/refman/5.5/en/forcing-innodb-recovery.html InnoDB: about forcing recovery. 140221 3:19:50 [ERROR] mysqld got signal 6 ; This could be because you hit a bug. It is also possible that this binary or one of the libraries it was linked against is corrupt, improperly built, or misconfigured. This error can also be caused by malfunctioning hardware. To report this bug, see http://kb.askmonty.org/en/reporting-bugs We will try our best to scrape up some info that will hopefully help diagnose the problem, but since we have already crashed, something is definitely wrong and this may fail. Server version: 5.5.35-MariaDB key_buffer_size=10485760 read_buffer_size=131072 max_used_connections=1 max_threads=502 thread_count=0 It is possible that mysqld could use up to key_buffer_size + (read_buffer_size + sort_buffer_size)*max_threads = 211932 K bytes of memory Hope that's ok; if not, decrease some variables in the equation. Thread pointer: 0x0x0 Attempting backtrace. You can use the following information to find out where mysqld died. If you see no messages after this, something went terribly wrong... stack_bottom = 0x0 thread_stack 0x48000 /usr/libexec/mysqld(my_print_stacktrace+0x2e)[0x7f037fbde42e] /usr/libexec/mysqld(handle_fatal_signal+0x505)[0x7f037f847a25] /lib64/libpthread.so.0(+0xef90)[0x7f037d686f90] /lib64/libc.so.6(gsignal+0x39)[0x7f037d2ec9e9] /lib64/libc.so.6(abort+0x148)[0x7f037d2ee0f8] /usr/libexec/mysqld(+0x63f008)[0x7f037fa03008] /usr/libexec/mysqld(+0x676218)[0x7f037fa3a218] /usr/libexec/mysqld(+0x5f8048)[0x7f037f9bc048] /lib64/libpthread.so.0(+0x7c53)[0x7f037d67fc53] /lib64/libc.so.6(clone+0x6d)[0x7f037d3acdbd] The manual page at http://dev.mysql.com/doc/mysql/en/crashing.html contains information that should help you find out what is causing the crash. 140221 3:19:52 InnoDB: The InnoDB memory heap is disabled 140221 3:19:52 InnoDB: Mutexes and rw_locks use GCC atomic builtins 140221 3:19:52 InnoDB: Compressed tables use zlib 1.2.7 140221 3:19:52 InnoDB: Using Linux native AIO 140221 3:19:52 InnoDB: Initializing buffer pool, size = 64.0M 140221 3:19:52 InnoDB: Completed initialization of buffer pool 140221 3:19:52 InnoDB: highest supported file format is Barracuda. InnoDB: Log scan progressed past the checkpoint lsn 153930874326 140221 3:19:52 InnoDB: Database was not shut down normally! InnoDB: Starting crash recovery. InnoDB: Reading tablespace information from the .ibd files... InnoDB: Restoring possible half-written data pages from the doublewrite InnoDB: buffer... InnoDB: Doing recovery: scanned up to log sequence number 153931613156 140221 3:19:53 InnoDB: Starting an apply batch of log records to the database... InnoDB: Progress in percents: 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 InnoDB: Apply batch completed InnoDB: In a MySQL replication slave the last master binlog file InnoDB: position 75471956, file name bin.000375 InnoDB: and relay log file InnoDB: position 75472234, file name ./mysql-relay-bin.001426 InnoDB: Last MySQL binlog file position 0 1179902, file name /data/mysql/mysql_dbmail/bin.000224 140221 3:19:53 InnoDB: Waiting for the background threads to start 140221 3:19:54 Percona XtraDB (http://www.percona.com) 5.5.35-MariaDB-33.0 started; log sequence number 153931613156 140221 3:19:54 [Note] Plugin 'FEDERATED' is disabled. 140221 3:19:54 [Note] Plugin 'FEEDBACK' is disabled. 140221 3:19:54 [Note] Server socket created on IP: '0.0.0.0'. 140221 3:19:55 [Note] Slave SQL thread initialized, starting replication in log 'bin.000375' at position 75471956, relay log './mysql-relay-bin.001426' position: 75472234 140221 3:19:55 [Note] Slave I/O thread: connected to master 'replication@******:3307',replication started in log 'bin.000376' at position 245 140221 3:19:55 [Note] Event Scheduler: Loaded 0 events 140221 3:19:55 [Note] /usr/libexec/mysqld: ready for connections. Version: '5.5.35-MariaDB' socket: '/var/lib/mysql/mysqld_dbmail.sock' port: 3307

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[Maria-discuss] Codership's Galera patch part of standard MariaDB
by Honza Horak 20 Feb '14

20 Feb '14

Hi guys, my Google-foo is poor today and I can't find any discussion about "inclusion of Codership's Galera patch to standard code-source of MariaDB". I'd like to see that one could just use the wresp plugin and have a working Galera cluster (even if that would mean to introduce new engine) without having another instance of the package. Is that technically possible at all and if so, are there any thoughts like this? Thanks, Honza

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[Maria-discuss] Doubt - replication and ssh/ssl
by Roberto Spadim 19 Feb '14

19 Feb '14

Hi guys, i'm with a doubt... What is better (better = more secure, and with good compression), a ssh tunnel, or a native mariadb ssl connection between master/slave replication mariadb servers? -- Roberto Spadim SPAEmpresarial Eng. Automação e Controle

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[Maria-discuss] Implementing APPROXIMATE_COUNT(*)
by Tomek R 19 Feb '14

19 Feb '14

Hi, I have realised that whenever I am doing any query and want to count number of rows:SELECT COUNT(*) FROM atable WHERE <complicated condition>; On large tables (>10e6 rows), when the count is >100e3, it takes over a second... even when all the indexes are set up, etc... and with large counts, I have not been able to go below ~<1 s. So I would like to implement APPROXIMATE_COUNT(*) function, which checks, if, for example every 10th, 100th or 1000th row is present in my final output... and based on this statistics, return the approximate number of rows that given query produces. I am using MyISAM engine and would like to do the implementation on it, where the total number of rows is automatically stored. Obviously, it would be useful for anybody dealing with these huge aggregate websites, where users do not really need to know if their keyword search returned 1234567890 results or just 1.2e9 results... Please, can you advise me how to start this project? I.e. whether it's easy to do in SQL or whether I would have to start looking somewhere in the source code of MariaDB? I have plenty of time, programming/SQL experience, but no experience with maria/mysql source code. Tomek

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[Maria-discuss] New Question: Data limit on joins with connect tables?
by AskMonty KB 18 Feb '14

18 Feb '14

Hello, A new question has been asked in "Connect" by benkendrick: -------------------------------- I am attempting run a query against two tables in a remote database with an inner join. These tables reside in a Progress Database. I have used the CONNECT engine via the ODBC connection that I have set up. The first query had 24 columns returned by the query, I got 930 rows as a result. If I reduce the number of columns that I select, the number of rows returned by the database goes up. Even with only two rows select, I only get about 12,000 rows. The total result should be 14,149 rows. I have used the same ODBC connection with LibreOffice Base and received the full number of rows. If I query each table individually, I get the full number of rows (The tables have a 1 to 1 relationship with the current data). I am using MariaDB 10.0.8 32-bit on Windows 7 querying a remote Progress Database. Is there some sort of data limit? I have noticed that the total number of data points (rows multiplied by columns) is between 20,000 and 24,000. -------------------------------- To view or answer this question please visit: http://mariadb.com/kb/en/data-limit-on-joins-with-connect-tables/

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[Maria-discuss] MySQL 5.6 optimizer trace functionality in MariaDB 10?
by Tim Callaghan 17 Feb '14

17 Feb '14

Is this feature or something similar already in MariaDB 10? If not, is it on the roadmap? http://dev.mysql.com/doc/internals/en/optimizer-tracing.html -Tim Callaghan

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[Maria-discuss] Potential participation in Google Summer of Code 2014
by Colin Charles 15 Feb '14

15 Feb '14

Hi! We have applied to be part of the Google Summer of Code 2014 project, and hope to gain some new contributors. If you are on this list and think you can be a mentor for a project, please consider writing a note at: https://mariadb.com/kb/en/google-summer-of-code-2014/ I think the aim for the GSoC students code should be for 10.1 inclusion If you have any queries, don't hesitate to ask me about them, I'm happy to help. Typically mentors need about 4 hours or so per week to assist the student in seeing their project become a reality I encourage many to participate as its a rewarding experience. In 2013, we did participate, and got 3 features out of it: SQL ROLES, PCRE regular expressions, and a Kerberos authentication plugin Looking forward to seeing more happen in 2014! (here's hoping we get accepted into GSoC 2014 of course!) cheers, -colin -- Colin Charles, Chief Evangelist MariaDB | t: +6-012-204-3201 | Skype: colincharles

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[Maria-discuss] MariaDB Galera Cluster 5.5.35 now available
by Daniel Bartholomew 14 Feb '14

14 Feb '14

The MariaDB project is pleased to announce the immediate availability of MariaDB Galera Cluster 5.5.35. This is a Stable (GA) release. See the Release Notes and Changelog for details. - - Links - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - MariaDB Galera Cluster 5.5.35 - Release Notes: https://mariadb.com/kb/en/mariadb-galera-cluster-5535-release-notes - Changelog: https://mariadb.com/kb/en/mariadb-galera-cluster-5535-changelog - Downloads: https://downloads.mariadb.org/mariadb-galera/5.5.35 About MariaDB Galera Cluster - https://mariadb.com/kb/en/galera/ APT and YUM Repository Configuration Generator: - https://downloads.mariadb.org/mariadb/repositories/ - - MariaDB Webinars - - - - - - - - - - - - - - - - - - - - - - - - - SkySQL has held several MariaDB-focused Webinars recently which are available on an on-demand basis at: - http://www.skysql.com/why-skysql/webinars/ They are also planning several more MariaDB-focused webinars that will be held over the comming months. Details available at the above link. - - New MariaDB Book - - - - - - - - - - - - - - - - - - - - - - - - - A new MariaDB book has been released! Getting Started with MariaDB is a how-to guide for beginners to help them get up to speed quickly with MariaDB, no previous MariaDB or MySQL experience required. It's available from several booksellers in both paperback and DRM-free epub, mobi and pdf formats. See the PacktPub website for details: - http://www.packtpub.com/getting-started-with-mariadb/book - - User Feedback plugin - - - - - - - - - - - - - - - - - - - - - - - MariaDB includes a User Feedback plugin. This plugin is disabled by default. If enabled, it submits basic, completely anonymous MariaDB usage information. This information is used by the developers to track trends in MariaDB usage to better guide development efforts. If you would like to help make MariaDB better, please add "feedback=ON" to your my.cnf or my.ini file! See http://mariadb.com/kb/en/user-feedback-plugin for more information. - - Quality - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - The project always strives for quality, but in reality, nothing is perfect. Please take time to report any issues you encounter at: - http://mariadb.org/jira - - Support MariaDB - - - - - - - - - - - - - - - - - - - - - - - - - - If you would like to contribute to the MariaDB Foundation, please see the "contributing" and "donations" pages. We also have merchandise available in a cafepress store. All proceeds go to support the MariaDB Foundation. - https://mariadb.com/kb/en/contributing - https://mariadb.org/en/donate/ - http://www.cafepress.com/mariadb We hope you enjoy MariaDB! -- MariaDB: An Enhanced Drop-in Replacement for MySQL Website - http://mariadb.org Twitter - http://twitter.com/mariadb Google+ - http://google.com/+mariadb Facebook - http://fb.com/MariaDB.dbms Knowledge Base - http://mariadb.com/kb

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[Maria-discuss] Very slow insert with load data infile
by Pierre 12 Feb '14

12 Feb '14

Hello, Mariadb is getting slower and slower when I'm inserting a massive amout of data. I'm trying to insert 166 507 066 rows (12go) using load data infile '' into an empty table. I splitted my file in 13 parts of the same size because it was too long to insert in one shot. When I inserted more than 100M rows, it starts to be extremely slow. Here are the time for each load data infile : LOAD DATA INFILE '/tmp/hash/xaa' : 2min 49sec LOAD DATA INFILE '/tmp/hash/xab' : 2min 49sec LOAD DATA INFILE '/tmp/hash/xac' : 3min 48sec LOAD DATA INFILE '/tmp/hash/xad' : 3min 48sec LOAD DATA INFILE '/tmp/hash/xae' : 3min 49sec LOAD DATA INFILE '/tmp/hash/xaf' : 5min 59sec LOAD DATA INFILE '/tmp/hash/xag' : 10min 50sec LOAD DATA INFILE '/tmp/hash/xah' : 20min 7sec LOAD DATA INFILE '/tmp/hash/xai' : 47min 7sec LOAD DATA INFILE '/tmp/hash/xaj' : 4 hours 1 min 9.34 sec ( ouch !) LOAD DATA INFILE '/tmp/hash/xak' : still running... Now the task is running but mariadb is only using 2% cpu and read to the disk at 2500 Kb/sec (which is slow regarding the disk performance). There is a lot of disk space. If insertion speed continue to slow down at this rate, it will take weeks to insert the 3 remainings files ! It's only 166M rows so I think it's not normal. If I disable the "unique" constraint insertion speed is great but I need to be sure there is no duplicate and I also need an index. Can someone explain me what is happening internaly and why it is so slow ? Do you think if I just create an index (not a unique index) it will be faster ? The problem is I specially delegated this task of unique checking to mysql. If no solution, do you know a database or a key/value store with better for performance for this use case ? (create an index and remove duplicate ?) I can rearrange my table structure (at a cost of more disk space usage) to match a key/value structure. Here is my current table structure : CREATE TABLE `wallets` ( `p1` varbinary(20) DEFAULT NULL, `p2` varbinary(20) DEFAULT NULL, `data` varbinary(32) DEFAULT NULL, UNIQUE KEY `p1` (`p1`), UNIQUE KEY `p2` (`p2`) ) ENGINE=MyISAM DEFAULT CHARSET=utf8 ROW_FORMAT=FIXED; Computer specs: 16go RAM and 4x3.1 ghz, 2x1To (with 90% unused disk space) The configuration variables (I tweaked specially for this insertion job) : key_buffer_size = 6G # MyISAM: used with insert to an empty table bulk_insert_buffer_size = 6G # MyISAM/Aria: insert to a non empty table; default 8M myisam_sort_buffer_size = 6G # MyISAM: used for sort but only when : "CREATE INDEX", "ALTER TABLE" or "REPAIR TABLE" read_buffer_size = 6G # MyISAM/Aria/MERGE: allocated for each table scan, for order by, nested query caching, bulk insert into partitions sort_buffer_size = 4M # ALL: allocated each time a session need to do a sort myisam_max_sort_file_size = 128G # MyISAM: tmp file max size I'm using mariadb 5.5.31. Best regards,

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