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[Maria-developers] I_S plugin doubts
by Roberto Spadim 13 Jun '13

13 Jun '13

Hi i was reading locale_info and qc_info source that i sent in jira changing the last parameter from 0 to SKIP_OPEN_TABLE, change the table from aria engine to memory engine, why? this change something internally in I_S table ? example: from static ST_FIELD_INFO qc_info_fields_queries[]= { {"ENTRY_POSITION_IN_CACHE", MY_INT32_NUM_DECIMAL_DIGITS, MYSQL_TYPE_LONG, 0, 0, 0, 0}, ... to static ST_FIELD_INFO qc_info_fields_queries[]= { {"ENTRY_POSITION_IN_CACHE", MY_INT32_NUM_DECIMAL_DIGITS, MYSQL_TYPE_LONG, 0, 0, 0, SKIP_OPEN_TABLE}, ... -- Roberto Spadim

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Re: [Maria-developers] MDEV-4581 , more query cache information fields
by Roberto Spadim 12 Jun '13

12 Jun '13

hi sergei, i sent the patch, could you check it? i think that's easy to read and understand maybe some code standard should be done since i don't know how code in mariadb cs https://mariadb.atlassian.net/browse/MDEV-4581

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[Maria-developers] MDEV-4581 , more query cache information fields
by Roberto Spadim 12 Jun '13

12 Jun '13

Hi guys, i sent a patch for qc_info plugin in MDEV-4581 Could mariadb team review and tell me what i should do, to put it in the next release? i will rewrite it, at 10.0.3 release, and change some things: the add to query to cache, i will change to only a function call at sql_cache.cc, and put the function at sql_cache.h something like: qc->qc_info_set_informations(insert time, rows_sent, rows_read, etc etc etc) rewrite the part of query hit. to execute only a command too qc->qc_info_hit(current_time, expend_qc_time, etc etc etc) this will make sql_cache.cc code cleaner and sql_cache.h "dirty" but will be more easly to read and patch future versions. only add 2 lines to sql_cache.cc , and many lines to sql_cache.h since sql_cache.h have the structure it will be easly to write function call at struct than sql_cache.cc file bye guys -- Roberto Spadim

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Re: [Maria-developers] audit plugin help with MDEV-575 (fail2ban like)
by Roberto Spadim 12 Jun '13

12 Jun '13

well i'm thinking about again, maybe just a syslog could do the job with fail2ban but in windows... well it will not work maybe the second option of a internal table could do the job too Host | bad_login_datetime if host have more than 'bad_login_tries' bad logins in 'bad_login_seconds' seconds before now it will be disconnect after xxx seconds or after each minute, or after each disconnect clean the internal table that have bad_login_datetime < now() - 'bad_login_seconds' the clean should be optimized in a not paintfull way (maybe like a garbage colector that runs after X disconnects, or a event that happens each x seconds, or both of them, i prefer the disconnect method) any other idea?

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Re: [Maria-developers] [Commits] Rev 3551: MDEV-4612 SQ pushdown: Server crashes in make_join_statistics with materialization+semijoin, IN subqueries, constant table, impossible condition in file:///home/tsk/mprog/src/10.0-md83/
by Oleksandr Byelkin 11 Jun '13

11 Jun '13

Hi! 11.06.2013 11:11, timour(a)askmonty.org пишет: > At file:///home/tsk/mprog/src/10.0-md83/ > > ------------------------------------------------------------ > revno: 3551 > revision-id: timour(a)askmonty.org-20130611081135-rge7p00h8e9nhypj > parent: timour(a)askmonty.org-20130528122232-kisslvdw5vhrna0q > fixes bug: https://mariadb.atlassian.net/browse/MDEV-4612 > committer: timour(a)askmonty.org > branch nick: 10.0-md83 > timestamp: Tue 2013-06-11 11:11:35 +0300 > message: > MDEV-4612 SQ pushdown: Server crashes in make_join_statistics with materialization+semijoin, IN subqueries, constant table, impossible condition > > Analysis: > The subquery materialization execution method subselect_hash_sj_engine::exec() > didn't restore thd->lex->current_select through all return paths. This was > not a problem when the method is called during execution. When a subquery > was executed during the optimization phase of the outer query, current_select > remained to point to the wrong subquery. This resulted in update_ref_and_keys() > getting the wrong number of conditions via thd->lex->current_select->cond_count, > thus allocating a smaller buffer for sargable conditions. This later resulted > in memory overwrite. > > Solution: > Make sure that subselect_hash_sj_engine::exec() always restores current_select. The patch looks OK to push. [skip]

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[Maria-developers] Group commit comparison between mysql and mariadb
by Sergei Petrunia 11 Jun '13

11 Jun '13

Hi Kristian, I'm wondering, do we have any comparison of MariaDB's binlog group commit implementation vs MySQL's binlog's group commit? I recall Mats writing a blog about the differences last year, but he didn't have the code back then. I'm wondering if Oracle had implemented what he described, or did something else... I understand that in order to do benchmark we need to finish merging InnoDB from MySQL 5.6 into MariaDB 10.0. One can't benchmark group commit per se, it is tied to innodb. Do we still have any clue, before the merge happens? Btw, what should the merge do - take group commit from MariaDB or from MySQL? BR Sergei -- Sergei Petrunia, Software Developer Monty Program AB, http://askmonty.org Blog: http://s.petrunia.net/blog

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Re: [Maria-developers] Buildbot question
by Kristian Nielsen 11 Jun '13

11 Jun '13

Sergey Vojtovich <svoj(a)mariadb.org> writes: > I'm observing pretty odd buildbot behavior with some of my pushes (probably > merges). Bar and Daniel were unable to answer my questions and suggested to > ask you instead. The problem seems to be that Buildbot has become confused about revisions. Look at the top of the page you linked, at the revisions for each column. You will notice that they are not in order. The 3rd column is the highest revision, which is probably why spider suite is enabled there (I assume you pushed something to add the suite). I see your current top revision in the tree is 3760, while the Buildbot page has a newer revision 3767. It also looks like the Buildbot history contains _another_ earlier revision that was also number 3760, maybe that is the cause of the confusion (Buildbot perhaps thinks it is rebuilding the old 3760). You can see your revision sorted as the first columns in this link: http://buildbot.askmonty.org/buildbot/grid?branch=10.0-spider&width=20 This confusion usually happens because the tree was overwritten and revisions became renumbered. This can happen due to bzr push --overwrite, but in your case it is probably because you merged in the opposite direction. When merging a tree A with a tree B and pushing to B, it is generally best to merge A into B (cd to B and bzr merge A). This keeps the existing revision numbers of B intact. In the main trees we have protection that enforces this, but not in feature trees. (I would be nice if we could fix Buildbot to prevent this confusion, but so far noone has taken it upon themselves. At one point I asked the Launchpad/bzr developers to make the revision id (as opposed to revision numbers) available so that Buildbot could avoid using revision numbers completely, but the answer was that "hiding revision ids was a feature" ...). Usually the confusion is sorted out by itself on a following push, or you can use the trick above adding width=N to the link to see the column of the revision you want. Hope this helps, - Kristian.

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[Maria-developers] MariaDB 10.0.3 release prep
by Daniel Bartholomew 11 Jun '13

11 Jun '13

All, I've begun the prep work for the MariaDB 10.0.3 alpha release. The packages are uploaded and the mirrors should pick them up soon (if they haven't already). The draft changelog and release notes are here: - https://kb.askmonty.org/en/mariadb-1003-release-notes/ - https://kb.askmonty.org/en/mariadb-1003-changelog/ Please let me know ASAP if there's anything that needs to be mentioned/highlighted/removed/etc... Assuming all goes well, the plan is to activate the release tomorrow (11 Jun 2013) at around 10am US Eastern Time. Thanks. -- Daniel Bartholomew Google+ - http://gplus.to/dbart Twitter - http://twitter.com/daniel_bart 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 Knowledgebase - http://kb.askmonty.org

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[Maria-developers] audit plugin help with MDEV-575 (fail2ban like)
by Roberto Spadim 09 Jun '13

09 Jun '13

hi guys i want get users / ip that try to connect to server with bad password/user and retry very frequently (normally a brute force attack) some things i need: 1)get information about connection when it fail or not (maybe an audit plugin could do this?), information that i need: 1.1)protocol (tcp/unix/others) 1.2)user 1.3)remote ip (when tcp only) it must be executed in every login 2) log this information maybe we could use CSV,aria, myisam, to log bad logins and put it in a log table: PROTOCOL, USER, REMOTE IP, DATATIME 3) add columns to user BAD_LOGIN_MAX_TRIES, BAD_LOGIN_LOG_TIME, BAD_LOGIN_MIN_RETRY_TIME 4) add server global bad_login_tcp_log_time, bad_login_tcp_max_errors 5) implement checks before connection: when openned a connection to server via TCP execute something like: SELECT COUNT(*) FROM bad_login_log WHERE remote_ip="remote_ip" AND datetime>NOW() - @@bad_login_tcp_log_time if COUNT(*) > @@bad_login_tcp_max_erros disconnect 6) implement user checks: SELECT COUNT(*),(SELECT BAD_LOGIN_MAX_TRIES FROM users WHERE user="user") FROM bad_login_log WHERE user="user" AND datetime>NOW() - (SELECT BAD_LOGIN_LOG_TIME FROM users WHERE user="user") if count(*) > bad_login_max_tries form that user disconnect that's all -- Roberto Spadim SPAEmpresarial

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[Maria-developers] Help with MDEV-4419, ENUM optimization
by Roberto Spadim 09 Jun '13

09 Jun '13

Hi guys, i want to optimize fields with ENUM() in item comparation the point is: SELECT COUNT(*) FROM table WHERE enum_field!='x' column 'enum_field' is ENUM('x,'y','z') NOT NULL DEFAULT 'x' i want to rewrite the query in a way that we can execute it with index: SELECT COUNT(*)FROM table WHERE enum_field IN ('y','z','') the "" is not allowed values ('a' for example) the feature is 'easy' to understand but i don't know where to implement it will read possible values of enum fields, and rewrite "!=","<","<=",">=",">" operators to IN operator with fields that match the condition of the primary operator some think like: column "operator" const value if(operator in ('!=','<','<=','>=','>' AND column is ENUM){ get all possible values from column copy all values to a return variable execute the "operator" in all values with const values if operator return false remove the value from the return variable change the "operator" and "const value" to : "IN" and return variable comma separated }else{ no optimization leave operation as it is } example: column = enum('x','y','z'), operator = ">" const value = "3" if(column is ENUM and operator = ">"){ possible values => "x","y","z","" (check that "" is used when insert into, value = "a" for example) return variable = "x","y","z", "" for each value.... "x" > "3" ? yes, ASCII 120 > ASCII 51 -> do nothing "y" > "3" ? yes, ASCII 121 > ASCII 51 -> do nothing "z" > "3" ? yes, ASCII 122 > ASCII 51 -> do nothing "" > "3" ? no, "" < ASCII 51 -> remove the value "" from return variable end for now the return variable is : "x","y","z" the "" was removed rewrite the operator to: "column IN ('x','y','z')" } ----------------------- this will optimize a lot: using != in a big table (446577 rows) result = Using where, 446577 rows, type= ALL using IN() in a big table: result = Using where, 28 rows, key = index, type = range in other words, a lot of optimization with ENUM fields, since they are a pseudo "index" of what we can found in the column =) thank guys any help is wellcome to make a patch -- Roberto Spadim SPAEmpresarial

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