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[Maria-developers] can "set read_only" be non-blocking?
by MARK CALLAGHAN 27 Jun '11

27 Jun '11

It can be dangerous for us to run "set read_only" on a production server because it can block in close_cached_tables. More details about the pain this caused at a previous job are at: http://mysqlha.blogspot.com/2008/07/what-exactly-does-flush-tables-with.html Per the code in set_var.cc: /* Perform a 'FLUSH TABLES WITH READ LOCK'. This is a 3 step process: - [1] lock_global_read_lock() - [2] close_cached_tables() - [3] make_global_read_lock_block_commit() [1] prevents new connections from obtaining tables locked for write. [2] waits until all existing connections close their tables. [3] prevents transactions from being committed. */ Can there be a variant that doesn't do #2? My workload doesn't use MyISAM and I don't know if #2 is done because of MyISAM. Calling close_cached_tables seems like a heavy way to force LOCK TABLEs to be unlocked. Any long running queries will cause #2 to block. -- Mark Callaghan mdcallag(a)gmail.com

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Re: [Maria-developers] [Commits] Rev 3062: Fixed LP bug #801536. in file:///home/igor/maria/maria-5.3-merge-tmp/
by Timour Katchaounov 27 Jun '11

27 Jun '11

Igor, Ok to push in the sense that the new patch cannot any more result in overflow. Both the old and new code are not equivalent. Given there is no comment, I cannot fully understand whether the change produces at least as good estimate of the record length as the old patch. Could you please add some general comment to the whole function how do we compute the field length. Timour On 27.06.2011 07:55, Igor Babaev wrote: > At file:///home/igor/maria/maria-5.3-merge-tmp/ > > ------------------------------------------------------------ > revno: 3062 > revision-id: igor(a)askmonty.org-20110627045532-663o9eih0flql0n6 > parent: igor(a)askmonty.org-20110625210227-kdneawayskx5jl4q > committer: Igor Babaev<igor(a)askmonty.org> > branch nick: maria-5.3-merge-tmp > timestamp: Sun 2011-06-26 21:55:32 -0700 > message: > Fixed LP bug #801536. > Ensured valid calculations of the estimates stored in JOIN_TAB::used_fieldlength. >

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[Maria-developers] WL#201 New (by Knielsen): Multi-source replication
by worklog-noreply＠askmonty.org 23 Jun '11

23 Jun '11

----------------------------------------------------------------------- WORKLOG TASK -=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=- TASK...........: Multi-source replication CREATION DATE..: Thu, 23 Jun 2011, 12:50 SUPERVISOR.....: IMPLEMENTOR....: COPIES TO......: CATEGORY.......: Server-RawIdeaBin TASK ID........: 201 (http://askmonty.org/worklog/?tid=201) VERSION........: Server-9.x STATUS.........: Un-Assigned PRIORITY.......: 60 WORKED HOURS...: 0 ESTIMATE.......: 0 (hours remain) ORIG. ESTIMATE.: 0 PROGRESS NOTES: DESCRIPTION: This worklog is about implementing a way for a MariaDB replication slave to replicate from more than one master simultaneously. Each master is handled by a specific replicator instance in the slave server. Each replicator instance consists of separate I/O thread, SQL thread, and associated state and configuration. In efffect, several replication slaves are running at the same time, each replicating from a separate master, but all replicating into a common data store (typically, but not necessarily to separate databases/tables). A replicator instance is identified with a user-chosen name used in replication SQL statements such as CHANGE MASTER TO ... This name is also included in file names to distinguish the files that keep the replication state (relay logs, master.info, relay-log.info). This way, each separate instance can be configured separately, but otherwise the same way as existing single-source replication. In order to remain backwards-compatible with existing third-party scripts etc., the replicator instance name is made optional in all existing replication statements. If it is omitted, the name "default" is used, and for this particular name, master.info and the other files retain their old names to allow seamless upgrades of slaves. In this worklog, there is no extra conflict resolution proposed. The effect of updates from one master on replication from another master will be the same as the effect of direct user SQL queries on the slave server, ie. it is the responsibility of the user/DBA to ensure no conflicts occur. If a conflict causes replication of an event to fail (with duplicate key violation eg.), the corresponding slave SQL thread will stop, requiring manual intervention to fix and start. An easy and typical way to avoid conflicts would be to eg. to use separate databases for each master->slave replication channel. RBR idempotent slave application can also be used to help resolve conflicts, for example. See also MySQL WL#1697: http://forge.mysql.com/worklog/task.php?id=1697 ESTIMATED WORK TIME ESTIMATED COMPLETION DATE ----------------------------------------------------------------------- WorkLog (v4.0.0)

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[Maria-developers] 5.5 merge: sql_select.cc
by Sergei Golubchik 23 Jun '11

23 Jun '11

Hi. Here I'll list changesets that cause conflicts and ask what to do. 1. http://tinyurl.com/63tey39 vs. http://tinyurl.com/5v2pluf it's a fix for bug#49322. both changes are similar, return is moved down. But Igor put it after the while() loop, while Ole John - in the loop, as soon a non-match is found. What difference does it make, I mean the earlier return, what consequences? 2. http://tinyurl.com/69lwrp9 - a big chunk is moved around in test_if_skip_sort_order() that's all, the rest of the file I've merged already. Regards, Sergei

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[Maria-developers] forwarded message from Kristian Köhntopp
by Michael Widenius 21 Jun '11

21 Jun '11

Hi! Here is booking.com's wish list! Regards, Monty

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[Maria-developers] MariaDB limits
by Marian Marinov 21 Jun '11

21 Jun '11

Hello guys, I have a lot of clients requesting some kind of per user limiting based on the information from the STATISTICS tables. I'm thinking of creating a patch that will add this functionality by creating two more tables in the INFORMATION_SCHEMA: USER_LIMITS CLIENT_LIMITS They will have some parts of the structure of USER_STATISTICS and CLIENT_STATISTICS and will keep only values for limits. By default a 0 would mean no limit. Do you have any comments about my aproach? Would you be willing to accept a patch that adds such functionality? I want to know before I start work on this project if the community is interested in such enhancement of MariaDB. Regards, Marian

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Re: [Maria-developers] Notes from the two IT Day Sessions
by Michael Widenius 20 Jun '11

20 Jun '11

Hi! Follow up to last email. I will hope to have the worklog items for all the wishes done by Thursday. Regards, Monty

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[Maria-developers] MariaDB in EPEL
by Marian Marinov 20 Jun '11

20 Jun '11

Hello, I wish to package MariaDB for the EPEL repository. I have searched a bit to see if there were any efforts in that direction but I saw none. In 2009 there was some talk about MariaDB and Fedora, but that was it, only some talk. I have the time to prepare and test the MariaDB RPMs and to continue support them later. My idea is to have MariaDB RPMs as replacements of the default mysql installation. In order to do so, I first want the approval of the MariaDB developers. Best regards, Marian Marinov

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Re: [Maria-developers] Rev 2994: BUG#790513: MariaDB crashes on startup
by Sergei Golubchik 17 Jun '11

17 Jun '11

Hi, Sergey! On Jun 17, Sergey Petrunya wrote: > Hi Sergei, > > Could you please review the below: > > ------------------------------------------------------------ > revno: 2994 > committer: Sergey Petrunya <psergey(a)askmonty.org> > timestamp: Fri 2011-06-17 01:05:20 +0400 > message: > BUG#790513: MariaDB crashes on startup please use lp:790513 abbreviation for bugs. see 'bzr help bugs' for details. > - Let ha_resolve_by_name() print error in case it could locate > the needed plugin but the plugin hasn't yet been initialized. > One can hit this problem by having mysql.plugin of type=innodb. Okay, I see the problem. But why couldn't we just initialize *all* built-in plugins earlier, before accessing mysql.plugin table ? > === modified file 'sql/handler.cc' > --- a/sql/handler.cc 2011-05-03 16:10:10 +0000 > +++ b/sql/handler.cc 2011-06-16 21:05:20 +0000 > @@ -135,6 +135,12 @@ > if ((plugin= my_plugin_lock_by_name(thd, name, MYSQL_STORAGE_ENGINE_PLUGIN))) > { > handlerton *hton= plugin_data(plugin, handlerton *); > + if (!hton) > + { > + sql_print_error("Attempt to use a built-in plugin %*s before it " > + "has been initialized", name->length, name->str); > + return NULL; > + } > if (!(hton->flags & HTON_NOT_USER_SELECTABLE)) > return plugin; > Regards, Sergei

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Re: [Maria-developers] [Commits] Rev 3049: BUG#778406: Crash in hp_movelink with Aria engine and subqueries in file:///home/psergey/dev2/5.3-push3/
by Timour Katchaounov 17 Jun '11

17 Jun '11

Sergey, Ok to push. I'd rather add a comment to the block of code starting with: " // 1. Store the length " At least to me it was not obvious why it is the way it is. Timour > At file:///home/psergey/dev2/5.3-push3/ > > ------------------------------------------------------------ > revno: 3049 > revision-id: psergey(a)askmonty.org-20110615143701-cgzzcr5l4ot2cxjy > parent: psergey(a)askmonty.org-20110615134018-5g5jbhqhce43onz4 > committer: Sergey Petrunya<psergey(a)askmonty.org> > branch nick: 5.3-push3 > timestamp: Wed 2011-06-15 18:37:01 +0400 > message: > BUG#778406: Crash in hp_movelink with Aria engine and subqueries > -In do_sj_dups_weedout(), set nulls_ptr to point to NULL bytes (and not to length bytes) of the DuplicateWeedout column. > === modified file 'mysql-test/r/subselect_sj.result' > --- a/mysql-test/r/subselect_sj.result 2011-06-15 09:43:04 +0000 > +++ b/mysql-test/r/subselect_sj.result 2011-06-15 14:37:01 +0000 > @@ -1305,4 +1305,25 @@ > GROUP BY field2 ; > field2 > drop table t1, t2, t3; > +# > +# BUG#778406 Crash in hp_movelink with Aria engine and subqueries > +# > +CREATE TABLE t4 (f10 varchar(32) , KEY (f10)) ENGINE=Aria; > +INSERT INTO t4 VALUES ('x'),('m'),('c'); > +CREATE TABLE t1 (f11 int) ENGINE=Aria; > +INSERT INTO t1 VALUES (0),(0),(0); > +CREATE TABLE t2 ( f10 int) ENGINE=Aria; > +INSERT INTO t2 VALUES (0),(0),(0); > +CREATE TABLE t3 ( f10 int, f11 int) ENGINE=Aria; > +SELECT * > +FROM t4 > +WHERE f10 IN > +( SELECT t1.f11 > +FROM t1 > +LEFT JOIN t2 JOIN t3 ON t3.f10 = t2.f10 ON t3.f11 != 0 ); > +f10 > +x > +m > +c > +drop table t1,t2,t3,t4; > set @@optimizer_switch=@save_optimizer_switch; > > === modified file 'mysql-test/r/subselect_sj_jcl6.result' > --- a/mysql-test/r/subselect_sj_jcl6.result 2011-06-15 09:43:04 +0000 > +++ b/mysql-test/r/subselect_sj_jcl6.result 2011-06-15 14:37:01 +0000 > @@ -1313,6 +1313,27 @@ > GROUP BY field2 ; > field2 > drop table t1, t2, t3; > +# > +# BUG#778406 Crash in hp_movelink with Aria engine and subqueries > +# > +CREATE TABLE t4 (f10 varchar(32) , KEY (f10)) ENGINE=Aria; > +INSERT INTO t4 VALUES ('x'),('m'),('c'); > +CREATE TABLE t1 (f11 int) ENGINE=Aria; > +INSERT INTO t1 VALUES (0),(0),(0); > +CREATE TABLE t2 ( f10 int) ENGINE=Aria; > +INSERT INTO t2 VALUES (0),(0),(0); > +CREATE TABLE t3 ( f10 int, f11 int) ENGINE=Aria; > +SELECT * > +FROM t4 > +WHERE f10 IN > +( SELECT t1.f11 > +FROM t1 > +LEFT JOIN t2 JOIN t3 ON t3.f10 = t2.f10 ON t3.f11 != 0 ); > +f10 > +x > +m > +c > +drop table t1,t2,t3,t4; > set @@optimizer_switch=@save_optimizer_switch; > # > # BUG#49129: Wrong result with IN-subquery with join_cache_level=6 and firstmatch=off > > === modified file 'mysql-test/t/subselect_sj.test' > --- a/mysql-test/t/subselect_sj.test 2011-06-15 09:43:04 +0000 > +++ b/mysql-test/t/subselect_sj.test 2011-06-15 14:37:01 +0000 > @@ -1189,5 +1189,28 @@ > > drop table t1, t2, t3; > > +--echo # > +--echo # BUG#778406 Crash in hp_movelink with Aria engine and subqueries > +--echo # > +CREATE TABLE t4 (f10 varchar(32) , KEY (f10)) ENGINE=Aria; > +INSERT INTO t4 VALUES ('x'),('m'),('c'); > + > +CREATE TABLE t1 (f11 int) ENGINE=Aria; > +INSERT INTO t1 VALUES (0),(0),(0); > + > +CREATE TABLE t2 ( f10 int) ENGINE=Aria; > +INSERT INTO t2 VALUES (0),(0),(0); > + > +CREATE TABLE t3 ( f10 int, f11 int) ENGINE=Aria; > + > +SELECT * > +FROM t4 > +WHERE f10 IN > +( SELECT t1.f11 > +FROM t1 > +LEFT JOIN t2 JOIN t3 ON t3.f10 = t2.f10 ON t3.f11 != 0 ); > + > +drop table t1,t2,t3,t4; > + > # The following command must be the last one the file > set @@optimizer_switch=@save_optimizer_switch; > > === modified file 'sql/opt_subselect.cc' > --- a/sql/opt_subselect.cc 2011-06-06 22:50:46 +0000 > +++ b/sql/opt_subselect.cc 2011-06-15 14:37:01 +0000 > @@ -3515,7 +3515,6 @@ > } > > ptr= sjtbl->tmp_table->record[0] + 1; > - nulls_ptr= ptr; > > /* Put the the rowids tuple into table->record[0]: */ > > @@ -3531,6 +3530,7 @@ > ptr += 2; > } > > + nulls_ptr= ptr; > // 2. Zero the null bytes > if (sjtbl->null_bytes) > { > > _______________________________________________ > commits mailing list > commits(a)mariadb.org > https://lists.askmonty.org/cgi-bin/mailman/listinfo/commits

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