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[Maria-developers] MySQL 5.7.6 adds "statement digest" independent of P_S
by Peter Laursen 27 Mar '15

27 Mar '15

.. as well as configurable digest length. http://mysqlserverteam.com/mysql-statement-digests-configurable-max-lengths/ http://mysqlserverteam.com/mysql-statement-digests/ Will this be ported to MariaDB? IMO this is/was one of the (not so many) useful things in P_S. And better now. -- Peter -- Webyog

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[Maria-developers] In daemon plugin, THD problem.
by 김경남 27 Mar '15

27 Mar '15

Hi, Sergei! I'm writing daemon plugin . I hava a problem and don't find soultion yet. There is my code as below. ex)plugin.cc ----------------------------------------------------- pthread_handler_t monm_monitor(void *p) { .... THD* thd; thd = new THD; thd->thread_stack= (char*) &thd; tables.init_one_table("performance_schema", 18, "events_statements_current", 25, "events_statements_current", TL_READ); open_and_lock_tables(thd, &tables, FALSE, MYSQL_LOCK_IGNORE_TIMEOUT); ..... } static int monm_plugin_init(void *p __attribute__ ((unused))) { ... pthread_create(&mon_thread, &attr, monm_monitor,(void *) ctx)!= 0) .... } ------------------------------------------------------------- In monm_monitor function, THD* thd cause server crash. so I examined coredump. #6 0x0000000000598752 in THD::THD (this=0x7f9b64000930, is_wsrep_applier=false) at /home/windfree/workspace/ws-mariadb/maria-mon/sql/sql_class.cc:1015 I don't know the reason of crash. What I just want to is read events_statements_current's row by using internal interface in a daemon plugin. Is there a another way ? let me know the solution. Regards, Kyungnam. 김경남 부책임연구원 솔루션사업본부 정보기술 연구원 신기술개발팀 02-2099-6177 / 010-2208-3006 _____ 상기 메시지와 첨부화일 내에는 비밀정보가 포함되어 있을 수 있으며, 지정된 수신자에 한하여 조회 및 사용될 수 있습니다. 만약 송신자의 실수로 인하여 상기 메시지를 수신하였다면, 송신자에게 메시지를 반송해 주시고, 원본 메시지와 모든 사본을 폐기해 주시기 바랍니다. 상기 메시지의 전체 또는 일부에 대해 무단 열람, 사용, 공개, 배포하는 것은 금지되어 있습니다.(주)LG CNS. This message and its attachments may contain confidential information, and they are intended to be viewed or used by only the individuals specified in the message. If you have received this message in an error from the sender, please contact the sender immediately to notify the error and delete all of the message and its copies. It is prohibited to view, use, make public and/or distribute part or whole of this message without written permission.

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Re: [Maria-developers] [Org FW][RE]Re: init_one_table problem.
by sergei 25 Mar '15

25 Mar '15

Hi, 김경남! On Mar 25, 김경남 wrote: > Hi, Sergei ! > > below contents is my previous question . > > After sending email , I see the debug message.like below. > > "Assertion thd == current_thd() failed." > > My code contains. > > THD thd = new THD; > > so I changed my code as > > THD thd = current_thd; > > but thd is null. > > how to I fix it? Note that sql_acl.cc (for example) has THD *thd=new THD; thd->thread_stack= (char*) &thd; thd->store_globals(); All three lines are important. In particular, THD::store_global sets current_thd. Regards, Sergei

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[Maria-developers] init_one_table problem.
by 김경남 25 Mar '15

25 Mar '15

Hi ~ I hava a problem below code in my plugin. ---------------------------------- TABLE_LIST tables; TABLE table; tables.init_one_table(C_STRING_WITH_LEN("performance_schema"),C_STRING_W ITH_LEN("events_statements_current"), events_statements_current, TL_READ); if(table = tables.table) {...} ------------------------------------------------------- During debugging, I found that tables.table is null. Is there a additional task before my code? Regards, Kyungnam. 김경남 부책임연구원 솔루션사업본부 정보기술 연구원 신기술개발팀 02-2099-6177 / 010-2208-3006 _____ 상기 메시지와 첨부화일 내에는 비밀정보가 포함되어 있을 수 있으며, 지정된 수신자에 한하여 조회 및 사용될 수 있습니다. 만약 송신자의 실수로 인하여 상기 메시지를 수신하였다면, 송신자에게 메시지를 반송해 주시고, 원본 메시지와 모든 사본을 폐기해 주시기 바랍니다. 상기 메시지의 전체 또는 일부에 대해 무단 열람, 사용, 공개, 배포하는 것은 금지되어 있습니다.(주)LG CNS. This message and its attachments may contain confidential information, and they are intended to be viewed or used by only the individuals specified in the message. If you have received this message in an error from the sender, please contact the sender immediately to notify the error and delete all of the message and its copies. It is prohibited to view, use, make public and/or distribute part or whole of this message without written permission.

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Re: [Maria-developers] [RE]Re: I wonder what elements add to CMakeLists.txt
by Sergei Golubchik 25 Mar '15

25 Mar '15

Hi, kyungnam! On Mar 24, kyungnam wrote: > > I hava a question. > > I'm developing mariadb plugin . and I make a development environment > according to below url. > > https://mariadb.com/blog/compiling-debugging-mariadband-mysql-eclipse-scrat… > > I seperate source folder and package folder. > > During developing, I hava a trouble with too much build time. > > for example, after I edit sql_parse.cc (add one or two lines) , I run > command "make" under source root folder. > > The build time takes about 5 ~ 10min. and then I run command "make > package". That time takes about 10min. > > At first, I copied libmysqld.so.18 to package folder. but had no > effect. finally I run command "make package" and reinstall mariadb. > > I think I'm doing wrong things. > > please let me know the efficient way to build and debug. I'm not using Eclipse, so I'm afraid I cannot help you with that. If you just modify sql_parse.cc, the compilation should be fast and only that file has to be recompiled (and few binaries re-linked). If you see a lot of files recompiled than either you modified more than sql_parse.cc or your IDE is doing that for you. Make package needs to copy many files so it's a bit slow if you do it very often. I don't - unless I specifically work on packaging I run "make package" very rarely. You don't have to compile libmysqld every time. Run cmake -DWITH_EMBEDDED_SERVER=OFF in your build directory. Regards, Sergei

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[Maria-developers] Merge 10.0 -> 10.1
by Kristian Nielsen 25 Mar '15

25 Mar '15

I have some patches in 10.0 that have not yet been merged to 10.1. Today I attempted the merge, but there were a few conflicts that I was not sure how to handle. Some charset-related functions touching fields that had moved to another struct, some error handling functions in XtraDB with new extra arguments. In case someone else does the merge, I just wanted to point out one conflict in one of my patches in the 10.0 -> 10.1 merge, as the correct resolution is not obvious: <<<<<<< HEAD if (mysql_bin_log.is_open()) return true; ||||||| merged common ancestors ======= if (mysql_bin_log.is_open() && opt_binlog_commit_wait_count > 0) return true; >>>>>>> origin/10.0 The correct conflict resolution here is to leave the code as it was in 10.1: if (mysql_bin_log.is_open()) return true; Or I can do the complete 10.0 -> 10.1 merge if necessary, figuring out the other conflicts, but I did not want to do that without coordinating, to avoid duplicating efforts. - Kristian.

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[Maria-developers] GSoC 2015: Table functions (a.k.a UDF returning arrays / result set) MDEV-5199
by Diwas Joshi 25 Mar '15

25 Mar '15

Hello, I am Diwas, a Masters' student at IIIT Hyderabad, India. I am interested to work on "Table functions (a.k.a UDF returning arrays / result set)". I have downloaded and built MariaDB 10.1 source code from github. I started going through the code. I realized UDF's for scalar values is already implemented in the code, so i began to analyze from there. I got myself acquainted with the query work-flow. I believe the work will be similar to create_function from sql_udf.cc for some part. I understand that I'll need some real storage mechanism for executing the functions in queries so I'll need to use the handler class for this. Please tell me how much of the project I have understood correctly and if I am on the right lines here and how can i proceed towards writing my proposal for this project. regards Diwas Joshi

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[Maria-developers] Port InnoDB memcached interface to MariaDB (GSOC 2015)
by Aalekh Nigam 24 Mar '15

24 Mar '15

Hello, I am Aalekh Nigam, 3rd Year Undergraduate student at JIIT Noida, India. I would like to propose my participation for Port InnoDB MemcacheInterface to MariaDB (https://mariadb.atlassian.net/browse/MDEV-4674) as GSOC 2015 Student. For the purpose of security following is the approach I have planned to accomplish for this project: The plugin will contain a xtradb_memcached.sql table for configuation option, these configuration options will also contain a username, password , tcp/udp address, port no. as column objects which will help us authenticate the connection for a specified user, thus on authentication the server would fetch corresponding tcp/udp address and port to connect with the memcached server. Hence this will not just prove an improvement to the existing mysql plugin but also provide a better security to the database. Nextly after connecting with a memcached server, our database will act as a NoSql system providing rapid user query transaction. Also please follow my proposal here: https://www.google-melange.com/gsoc/proposal/review/student/google/gsoc2015… Waiting for your comments regarding the approach. ---Aalekh

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Re: [Maria-developers] I wonder what elements add to CMakeLists.txt
by 김경남 24 Mar '15

24 Mar '15

Hi, Sergei! Thanks for your advice and I agree with you. Accoring to your advice, It's not a good plan to pass some data to my plugin agent from sql_parser.cc because it needs to compile mariadb server. So I hava a another concept. Instead of put some code to sql_parse.cc, plugin collects a some data like below sample conceptual code. I_List_iterator<THD> it(threads); while ((tmp_thd=it++)) { if ((tmp_thd->get_command() == COM_QUERY) ||(tmp_thd->get_command() == COM_STMT_EXECUTE) ) continue; char* sql = tmp_thd->query(); if(sql) { ... send_data(); } } In this case, I though that it doesn't need to compile maria server, but it need to recompile whenever structure of THD is changed. Can you accept that? Otherwise, if i hardcode directly into the server, can I contribute this community ? Additionally, you asked me about what information I want to collect. I want to collect data like below. * events_statements_current * events_stages_current * events_waits_current * events_statements_summary_by_digest These data easily collected by sql . but it's hard to collect by access memory.(THD or something else.) I wonder if it is possible to collect these data without using pfs (or psi) data structure. If it is possible, Is THD class is entry point or something else? If you don't mind, please let me know the best way to collect these data. Dear, kyungnam. ps: my email address changed from gmail to my company's mail address. ------------------------------------------------------------------------ ---- From: Sergei Golubchik <serg(a)mariadb.org> Date: 2015-03-24 0:11 GMT+09:00 Subject: Re: [Maria-developers] I wonder what elements add to CMakeLists.txt To: kyung nam Kim <knamkim(a)gmail.com> Cc: maria-developers(a)lists.launchpad.net Hi, kyung! On Mar 23, kyung nam Kim wrote: > Hi, Sergei! > Thanks for your reply. > You asked me about information which I want to send to my plugin. > I have a plan to develop monitoring tool for mariadb. > I want to develop a agent as a mariadb plugin. > Agent collect data from sql_parse.cc (I' don't know exactly where more > infomation about performance .) and sends that data to APM (Application > Performance Monitoring) Server. and Users use databoard to see that data > via APM server. > > We have already have a APM Server, Dashboard and many kinds of agent. (for > server, was). I want to add agent for mariaDB and contribute this community > if possible. Right. That's exactly why I ask. We cannot accept your plugin and it'll be of little use to the community (not "of no use", it'll be used, but less than it could've been) if one would need to modify and recompile MariaDB to use your plugin. If you'd like, let's try to figure out whether you can collect your infomation without patching the server. So what data do you need, exactly? > Your advice is right. It's easier my header file to sql folder. > But When I want to develop my agent as a plugin type, I meet error as > follows. > ============================================ > [ 98%] Built target mysqlserver > Linking CXX shared library libmysqld.so > ../../sql_parse.cc:linenum: undefined reference to 'Mymon::Mymon()' > ../../sql_parse.cc:linenum: undefined reference to 'Mymon::putData(THD* > thd); Of course. Because you want sql_parse.cc to call your plugin, your plugin *always must be in the server*. You cannot have it as a separate shared object. To do that, add the MANDATORY keyword to your MYSQL_ADD_PLUGIN() declaration in CMakeLists.txt Regards, Sergei _____ 상기 메시지와 첨부화일 내에는 비밀정보가 포함되어 있을 수 있으며, 지정된 수신자에 한하여 조회 및 사용될 수 있습니다. 만약 송신자의 실수로 인하여 상기 메시지를 수신하였다면, 송신자에게 메시지를 반송해 주시고, 원본 메시지와 모든 사본을 폐기해 주시기 바랍니다. 상기 메시지의 전체 또는 일부에 대해 무단 열람, 사용, 공개, 배포하는 것은 금지되어 있습니다.(주)LG CNS. This message and its attachments may contain confidential information, and they are intended to be viewed or used by only the individuals specified in the message. If you have received this message in an error from the sender, please contact the sender immediately to notify the error and delete all of the message and its copies. It is prohibited to view, use, make public and/or distribute part or whole of this message without written permission.

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[Maria-developers] I wonder what elements add to CMakeLists.txt
by kyung nam Kim 23 Mar '15

23 Mar '15

Dears. I'm a newer in maria develper community. I'm develping a simple plugin for monitoring. If I access from other module to my plugin interface, I wonder how and what elements add to CMakeLists.txt. for example, My plugin is daemon type and myplugin.h has a definition of public methodA. I want to use methodA in my plugin from sql/sql_parse.cc . I think that information of library is needed at build time. ( -L, -l option) I don't know how to add that elements to CMakeLists.txt. plz,let me know. Thanks in advance.

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