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[Maria-discuss] strange "increment" values on primary keys
by Janis Heller 01 May '19

01 May '19

Hey community, I’m running Server version: 10.3.13-MariaDB-1:10.3.13+maria~bionic-log mariadb.org binary distribution of mariaDB (galera cluster). For local development we are not using galera, inside our local dev team we’re using Server version: 5.7.26-0ubuntu0.18.04.1 (Ubuntu). After creating a table, I’ve started to run the database create commands, working fine, but when I run the database seeder, inserting some system config values to be used by the application itself later, I’ve got some strange behavior. See the table below: MariaDB [demo_database]> select * from system_configs WHERE 1=1; +----+------------------------------------+--------------------------------------------------------------------+ | id | key | value | +----+------------------------------------+--------------------------------------------------------------------+ | 4 | admin_address | XXXXXX | | 7 | XXXXXX | XXXXXX | | 10 | XXXXXX | XXXXXX | | 13 | XXXXXX | XXXXXX | | 16 | XXXXXX | XXXXXX | | 19 | XXXXXX | XXXXXX | | 22 | XXXXXX | XXXXXX | | 25 | XXXXXX | XXXXXX | | 28 | XXXXXX | XXXXXX | | 31 | XXXXXX | XXXXXX | | 34 | XXXXXX | XXXXXX | | 37 | XXXXXX | XXXXXX | | 40 | XXXXXX | XXXXXX | | 43 | XXXXXX | XXXXXX | | 46 | XXXXXX | XXXXXX | | 49 | XXXXXX | XXXXXX | | 52 | XXXXXX | XXXXXX | | 55 | XXXXXX | XXXXXX | | 58 | XXXXXX | XXXXXX | | 61 | XXXXXX | XXXXXX | | 64 | XXXXXX | 21600 | | 67 | XXXXXX | XXXXXX | | 70 | XXXXXX | https://some.domain.com | +----+------------------------------------+——————————————————————————————————+ Where XXXXXX stands for the key and XXXXXX for the value. The problem is the id itself. It’s somehow starting at 4 and is incremented by 3. As you may suspect now already, this will break our application, since some primary key ids are hard coded itself. Is there some way to „force“ maria DB to increment the IDs by „1“? I already this documentation entry: https://mariadb.com/kb/en/library/auto_increment/ <https://mariadb.com/kb/en/library/auto_increment/> But it doesn’t help, here’s what I tried: MariaDB [demo_database]> CREATE TABLE animals ( -> id MEDIUMINT NOT NULL AUTO_INCREMENT, -> name CHAR(30) NOT NULL, -> PRIMARY KEY (id) -> ); Query OK, 0 rows affected (0.014 sec) MariaDB [demo_database]> INSERT INTO animals (name) VALUES -> ('dog'),('cat'),('penguin'), -> ('fox'),('whale'),('ostrich'); Query OK, 6 rows affected (0.003 sec) Records: 6 Duplicates: 0 Warnings: 0 MariaDB [demo_database]> MariaDB [demo_database]> SELECT * FROM animals; +----+---------+ | id | name | +----+---------+ | 4 | dog | | 7 | cat | | 10 | penguin | | 13 | fox | | 16 | whale | | 19 | ostrich | +----+---------+ 6 rows in set (0.001 sec) MariaDB [demo_database]> ALTER TABLE animals AUTO_INCREMENT=20; Query OK, 0 rows affected (0.011 sec) Records: 0 Duplicates: 0 Warnings: 0 MariaDB [demo_database]> INSERT INTO animals (name) VALUES ('aardvark'); Query OK, 1 row affected (0.002 sec) MariaDB [demo_database]> INSERT INTO animals (name) VALUES ('aardvark'); Query OK, 1 row affected (0.003 sec) MariaDB [demo_database]> SELECT * FROM animals; +----+----------+ | id | name | +----+----------+ | 4 | dog | | 7 | cat | | 10 | penguin | | 13 | fox | | 16 | whale | | 19 | ostrich | | 25 | aardvark | | 28 | aardvark | +----+----------+ 8 rows in set (0.000 sec) MariaDB [demo_database]> exit Bye I’m unable to find a way to force mariaDB to use increment by 1, starting at 1, as our local mariaDB „development“ version does too. All the best from Germany; Janis

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[Maria-discuss] Bill Owens: Get Andrew Yang on 60 Minutes
by carlosla1987＠gmail.com 30 Apr '19

30 Apr '19

Hola. Acabo de firmar la petición "Bill Owens: Get Andrew Yang on 60 Minutes" y pensé que te podría interesar. Estamos intentando conseguir 7.500 firmas y necesitamos todo el apoyo que podamos conseguir. Puedes leer más y firmar la petición aquí: http://chng.it/fXhkx89bFX ¡Gracias! Carlos

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[Maria-discuss] Migration question - advice sought
by Richard Reina 28 Apr '19

28 Apr '19

I have about five MySQL slaves backing up a MySQL master. The master is rather old and I am planning on migrating to MariaDB. I was hoping I could I create a MariaDB slave that backs up the newest MySQL slave (making it a relay) and then make the Maria slave a master and add Maria slaves until MySQL is phased out. Does this sound like a good plan or would it be better to just create a new Maria Master with dumps and add Maria slaves to it? Thanks

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[Maria-discuss] Understanding access to data through a unique index (r_rows=NULL in ANALYZE)
by Barrendeitor 25 Apr '19

25 Apr '19

Hello, I'm using MariaDB 13.3.14 I have a very simple test table with an email column and I am using |ANALYZE|to see the behavior of the indexes. If I understand correctly the output of |ANALYZE|, '|rows'|indicates the estimate of records accessed in the table, and |'r_rows'|the actual number of accesses. (Am I correct?) If yes, the issue is that, for a query as simple as: | SELECT*FROMuserWHEREemail ='user(a)domain.com'| ||| -- user(a)domain.com exists in email column and it is unique| || If I create a normal index in the |'email'|field, |r_rows=|1. However, if I create a unique index, |r_rows|=|NULL|. If I understand correctly, a NULL value on 'r_rows' means that no access to data has been performed ( https://mariadb.com/kb/en/library/analyze-statement/ ). So my question is, if I have a valid result, how can it be that the table is not accessed? How is the data retrieved when a unique index is used? Here is my output (I remember that the email in the query exists): MariaDB [test2]> create index email on usuario(email); Query OK, 95236 rows affected (0.451 sec) Records: 95236 Duplicates: 0 Warnings: 0 MariaDB [test2]> analyze select * from usuario where email = 'nec.urna.et(a)volutpatornare.com'; +------+-------------+---------+------+---------------+-------+---------+-------+------+--------+----------+------------+-----------------------+ | id | select_type | table | type | possible_keys | key | key_len | ref | rows | r_rows | filtered | r_filtered | Extra | +------+-------------+---------+------+---------------+-------+---------+-------+------+--------+----------+------------+-----------------------+ | 1 | SIMPLE | usuario | ref | email | email | 302 | const | 1 | 1.00 | 100.00 | 100.00 | Using index condition | +------+-------------+---------+------+---------------+-------+---------+-------+------+--------+----------+------------+-----------------------+ 1 row in set (0.001 sec) MariaDB [test2]> drop index email on usuario; Query OK, 95236 rows affected (0.237 sec) Records: 95236 Duplicates: 0 Warnings: 0 MariaDB [test2]> create unique index email on usuario(email); Query OK, 95236 rows affected (0.484 sec) Records: 95236 Duplicates: 0 Warnings: 0 MariaDB [test2]> analyze select * from usuario where email = 'nec.urna.et(a)volutpatornare.com'; +------+-------------+---------+-------+---------------+-------+---------+-------+------+--------+----------+------------+-------+ | id | select_type | table | type | possible_keys | key | key_len | ref | rows | r_rows | filtered | r_filtered | Extra | +------+-------------+---------+-------+---------------+-------+---------+-------+------+--------+----------+------------+-------+ | 1 | SIMPLE | usuario | const | email | email | 302 | const | 1 | NULL | 100.00 | NULL | | +------+-------------+---------+-------+---------------+-------+---------+-------+------+--------+----------+------------+-------+ 1 row in set (0.001 sec) Regards. ||

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[Maria-discuss] gtid and current_pos vs slave_pos
by mariadb＠Biblestuph.com 24 Apr '19

24 Apr '19

I have four servers all running 10.3 as follows: A <=> B => C => D where server_ids are: A => 301 B => 302 C => 303 D => 304 I.E., A is a master to B, B is a master to A, B is also a master to C, and C is a master to D. In addition to their actual replicating DBs, all four servers also have a "norep" DB that is used to create temporary tables for local report processing (as well as any other possible writes we might want to make locally without affecting the slave chain). Historically we've prevented replication for the norep DB via: replicate_ignore_db = mysql,norep replicate_wild_ignore_table = mysql.%,norep.% Which is set as such on all four servers (the replicate_do and binlog_do/ignore flavor of filters are all unset). Writes to the A and B servers are programmatically controlled such that only one of the two servers will accept writes at any given moment. Server D writes binlogs for potential backup/disaster recovery, but has no attached slave. All that in mind, looking at the binary logs on D, I see this statement: # at 51363132 #190423 9:07:51 server id 302 end_log_pos 51363170 GTID 1-302-47886064 ddl /*!100001 SET @@session.server_id=302*//*!*/; /*!100001 SET @@session.gtid_seq_no=47886064*//*!*/; # at 51363170 #190423 9:07:51 server id 302 end_log_pos 51363324 Query thread_id=345449 exec_time=1800 error_code=0 SET TIMESTAMP=1556024871/*!*/; SET @@session.pseudo_thread_id=345449/*!*/; DROP TEMPORARY TABLE IF EXISTS `norep`.`locations` /* generated by server */ /*!*/; How is it that that statement made it all the way through to server D from B? Shouldn't it have been filtered out by server C? Next, I'm reading up on gtid-based replication with the thought that I would love to be able to do things like bring down C for maintenance and temporarily point D to B. I read the docs here: https://mariadb.com/kb/en/library/gtid/ however, in looking at the actual binary logs of the servers they don't seem to reflect the explanations that I read there especially in regards to gtid_current_pos vs. gtid_slave_pos. Specifically, when I look at the gtid_slave_pos on server D, which I thought was only supposed to reflect transactions that were actually replicated, I sometimes see statements coming from server C; these are temporary tables being written into norep on C. They are not actually replicating on D (at least as far as I can tell), and they don't show up D's binary log. So why would they be reflected in D's gtid_slave_pos? For example, just a moment ago SELECT @@GLOBAL.gtid_slave_pos on D showed this: 1-303-48758339 This transaction does not appear in D's binlog, which I would expect since it should not in fact actually be replicated. But because it is reflected in gtid_slave_pos, it seems to me that in my setup I cannot reliably use gtid_current_pos or gtid_slave_pos, since either may at any given time point to an entry on C that of course won't exist on B should I ever want to redirect D to B. Am I missing or mis-understanding something here? Cheers, Dan

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[Maria-discuss] How do I determine if versions of phpMyAdmin before 4.8.5 is SQL Injectable using sqlmap?
by Turritopsis Dohrnii Teo En Ming 17 Apr '19

17 Apr '19

Subject/Topic: How do I determine if versions of phpMyAdmin before 4.8.5 is SQL Injectable using sqlmap? Good evening from Singapore, Our customer (company name is Confidential/not disclosed) reported that their MySQL database has been found missing or was deleted a few times. They are using Ubuntu 16.04 LTS Linux server with Apache2 Web Server, MySQL and PHP (LAMP). We responded to these security incidents by changing the passwords of the regular user, root user, and MySQL database user root. We have also examined /var/log/auth.log and think that the hacker could not have come in through ssh or sftp over ssh. From /var/log/mysql/error.log, we can ascertain that the MySQL database has been deleted at certain timings. We have also found nothing abnormal after examining /var/log/apache2/access.log. Even though we have secured the Ubuntu Linux server by changing passwords, the hacker was still able to delete our customer's MySQL database again and again. I have already proposed to install ModSecurity Open Source Web Application Firewall (WAF) to defend against web application attacks but my boss has told me to put that on hold at the moment. In fact, I have already deployed ModSecurity 2.9.0 on a Ubuntu 16.04 LTS *Testing* server and found that it actively detects and logs Nessus and sqlmap vulnerability scans in blocking mode. Since we did not find any evidence that the hacker had breached our customer's Ubuntu 16.04 LTS production server through ssh or Teamviewer, we suspect that the hacker could have achieved it by SQL injection. I took the initiative of downloading and installing Nessus Professional 8.3.1 Trial version for Windows 64-bit. The vulnerability scan report generated by Nessus Web Application Tests shows that our customer is using a version of phpMyAdmin prior to 4.8.5 which could be vulnerable to SQL injection using the designer feature. Further research shows that I can use sqlmap to determine if phpMyAdmin is SQL injectable. I already have a Testing Ubuntu 16.04 LTS Linux server with a Testing MySQL database and a Testing phpMyAdmin 4.8.4. I have purposely installed phpMyAdmin 4.8.4 because this version was reported to be vulnerable to SQL injection using the designer feature, and our customer is using a vulnerable version, according to CVE-2019-6798 ( https://nvd.nist.gov/vuln/detail/CVE-2019-6798 ). Then I proceeded to download and execute sqlmap on our Ubuntu Linux desktop against our Testing server. No matter how many commands I try, sqlmap always report that phpMyAdmin 4.8.4 is *NOT* SQL injectable. Perhaps I was using the wrong sqlmap commands all the time? The following is one of the many sqlmap commands I have used. $ python sqlmap.py -u "https://www.EXAMPLE.com/phymyadmin/index.php?id=1" --level=1 --dbms=mysql --sql-query="drop database" Replace database by database name. May I know what is the correct sqlmap command that I should use to determine that my Testing phpMyAdmin 4.8.4 is SQL injectable? I would like to know if I can successfully drop/delete the Testing database on our Testing server. If I can successfully drop/delete the Testing MySQL database using sqlmap, I would be able to conclude that the hacker must have carried out SQL injection to drop/delete the customer's database. I have already turned off the Testing ModSecurity Web Application Firewall on our Testing server to allow sqlmap to go through. Please point me to any good tutorial on SQL injection using sqlmap. Maybe I do not understand SQL injection well enough. Our customer is also using a customised in-house inventory management system that relies on PHP application and MySQL database. Would open source Snort Intrusion Detection System (IDS) and Intrusion Prevention System (IPS) be able to detect and block SQL injection as well? Please advise. Thank you very much. -----BEGIN EMAIL SIGNATURE----- The Gospel for all Targeted Individuals (TIs): [The New York Times] Microwave Weapons Are Prime Suspect in Ills of U.S. Embassy Workers Link: https://www.nytimes.com/2018/09/01/science/sonic-attack-cuba-microwave.html ******************************************************************************************** Singaporean Mr. Turritopsis Dohrnii Teo En Ming's Academic Qualifications as at 14 Feb 2019 [1] https://tdtemcerts.wordpress.com/ [2] https://tdtemcerts.blogspot.sg/ [3] https://www.scribd.com/user/270125049/Teo-En-Ming -----END EMAIL SIGNATURE-----

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[Maria-discuss] Strange timestamp index behaviour / bug
by Reinis Rozitis 03 Apr '19

03 Apr '19

Hello, before reporting it as bug I wanted to understand what's really going on or how to investigate it further: Because of the DST changes we experienced a strange issue where afterwards a query suddenly wouldn't use an index on a timestamp column anymore and would do a full tablescan and because of the table size literally brought down the db. The table itself is more complex but I could simplify it down to: CREATE TABLE `tmp` ( `id` int(10) unsigned NOT NULL AUTO_INCREMENT, `ts` timestamp NOT NULL DEFAULT current_timestamp(), PRIMARY KEY (`id`), KEY `ts_2` (`ts`) ) ENGINE=InnoDB CHARSET=utf8mb4 COLLATE=utf8mb4_unicode_ci; (the original table is TokuDB but the same behavior happens also on InnoDB / Server Mariadb 10.3.13): And the issue is: MariaDB [db]> explain select * from tmp where `ts` > '2019-03-31 03:00:00'; +------+-------------+-------+-------+---------------+------+---------+------+------+--------------------------+ | id | select_type | table | type | possible_keys | key | key_len | ref | rows | Extra | +------+-------------+-------+-------+---------------+------+---------+------+------+--------------------------+ | 1 | SIMPLE | tmp | index | ts_2 | ts_2 | 4 | NULL | 1000 | Using where; Using index | +------+-------------+-------+-------+---------------+------+---------+------+------+--------------------------+ While actually: MariaDB [db]> select count(*) from tmp where `ts` > '2019-03-31 03:00:00'; +----------+ | count(*) | +----------+ | 175 | +----------+ So either the sql optimizer or the engine does something strange. While for example: MariaDB [db]> explain select * from tmp where `ts` > '2019-03-31 04:00:00'; +------+-------------+-------+-------+---------------+------+---------+------+------+--------------------------+ | id | select_type | table | type | possible_keys | key | key_len | ref | rows | Extra | +------+-------------+-------+-------+---------------+------+---------+------+------+--------------------------+ | 1 | SIMPLE | tmp | range | ts_2 | ts_2 | 4 | NULL | 175 | Using where; Using index | +------+-------------+-------+-------+---------------+------+---------+------+------+--------------------------+ .. works as expected. The data is basically (just missing the 3:xx because of the clock spin): | 35458195 | 2019-03-31 02:55:44 | | 35458196 | 2019-03-31 02:55:45 | | 35458197 | 2019-03-31 02:56:37 | | 35458198 | 2019-03-31 02:59:16 | | 35458199 | 2019-03-31 02:59:39 | | 35458200 | 2019-03-31 04:01:42 | | 35458201 | 2019-03-31 04:02:59 | | 35458202 | 2019-03-31 04:04:02 | | 35458203 | 2019-03-31 04:04:26 | | 35458204 | 2019-03-31 04:04:38 | In the Innodb case the explain while showing that it will return all rows (the test table has 1000) also showing that it will use the 'ts_2' index on the original tokudb table it won't use the index even forced: MariaDB [db]> explain select * from twitt_ext_posts_url where `ts` > '2019-03-31 04:00:00'; +------+-------------+---------------------+-------+---------------+------+---------+------+-------+-------------+ | id | select_type | table | type | possible_keys | key | key_len | ref | rows | Extra | +------+-------------+---------------------+-------+---------------+------+---------+------+-------+-------------+ | 1 | SIMPLE | twitt_ext_posts_url | range | ts_2 | ts_2 | 4 | NULL | 42444 | Using where | +------+-------------+---------------------+-------+---------------+------+---------+------+-------+-------------+ .. works again fine, but: MariaDB [db]> explain select * from twitt_ext_posts_url where `ts` > '2019-03-31 03:00:00'; +------+-------------+---------------------+------+---------------+------+---------+------+----------+-------------+ | id | select_type | table | type | possible_keys | key | key_len | ref | rows | Extra | +------+-------------+---------------------+------+---------------+------+---------+------+----------+-------------+ | 1 | SIMPLE | twitt_ext_posts_url | ALL | ts_2 | NULL | NULL | NULL | 28547845 | Using where | +------+-------------+---------------------+------+---------------+------+---------+------+----------+-------------+ MariaDB [db]> explain select * from twitt_ext_posts_url force index(ts_2) where `ts` > '2019-03-31 03:00:00'; +------+-------------+---------------------+------+---------------+------+---------+------+----------+-------------+ | id | select_type | table | type | possible_keys | key | key_len | ref | rows | Extra | +------+-------------+---------------------+------+---------------+------+---------+------+----------+-------------+ | 1 | SIMPLE | twitt_ext_posts_url | ALL | ts_2 | NULL | NULL | NULL | 28547872 | Using where | +------+-------------+---------------------+------+---------------+------+---------+------+----------+-------------+ Is this to be expected or a bug? Should a gap in index values drop the index use for range queries? Is there anything else I need to add to the report? rr

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[Maria-discuss] required mysql_upgrade; MDEV-14637
by Michal Schorm 03 Apr '19

03 Apr '19

Hello, I have a questions regarding the warnings showing up at 10.2 and 10.3 releases: When upgrading from MariaDB 10.2.16 or earlier to MariaDB 10.2.17 or higher, running mysql_upgrade is required due to changes introduced in MDEV-14637. When upgrading from MariaDB 10.3.8 or earlier to MariaDB 10.3.9 or higher, running mysql_upgrade is required due to changes introduced in MDEV-14637. -- 1) The same applies for upgrading <=10.2.16 to >= 10.3.9, right? 2) Does it mean, it is impossible to use "dump and restore" technique, or it only means I need to run the mysql_upgrade afterwards? 3) The problem is not triggered when upgrading from 5.5, 10.0 and 10.1? 4) The problem is not triggered when upgrading to 10.4 ? -- Michal Schorm Software Engineer Core Services - Databases Team Red Hat --

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[Maria-discuss] Row vs Statement Replication in 10.3
by mariadb＠biblestuph.com 02 Apr '19

02 Apr '19

Using binlog-format=MIXED I'm trying to get my head around why certain statements are being written as RBR instead of as a statement. On my 10.3 test server running a fraction of my full load binary logs are getting written to the tune of about 30M/minute (the 5.5 production server with a currently much heavier load writes about 8.5M/minute). All of the tables are currently MyISAM. Here's a couple examples: This always gets written as a statement in 10.3: UPDATE mydb.t1 SET rundate = '2019-03-28 23:04:00' , runtime = UTC_TIMESTAMP() , runstatus = 1 WHERE hostname = 'my.host.com' While this always gets written as a row: UPDATE mydb.t1 SET rundate = '2019-03-28 23:04:00' , runtime = UTC_TIMESTAMP() , runstatus = 10 WHERE hostname = 'my.host.com' If it matters, runstatus (the only difference in the two) is a TINYINT(3) UNSIGNED NOT NULL DEFAULT 0. Both statements are written as statements in 5.5. And this one always gets written as RBR on 10.3, but I don't see why. I reviewed the information at https://mariadb.com/kb/en/library/unsafe-statements-for-statement-based-rep… but can't seem to see what is triggering it. UPDATE mydb.t1 AS i LEFT JOIN mydb.t2 AS j1 ON ( i.f1 = j1.f1 ) LEFT JOIN mydb.t3 AS j2 ON ( i.f1 = j2.f1 AND i.f2 > 0 AND i.f2 = j2.f2 ) SET i.f3 = IF ( i.f2 < 0, IF ( j1.f3 IS NULL, i.f3, j1.f3 ), IF ( j2.f3 IS NULL, i.f3, j2.f3 ) ) , i.f4 = IF ( i.f2 < 0, IF ( j1.f3 IS NULL, i.f4, j1.f3 ), IF ( j2.f3 IS NULL, i.f4, j2.f3 ) ) WHERE i.f5 != 0 AND i.f2 != 0 AND i.f6 = 1 AND i.f7 = 0 The 10.3 logs don't offer anything by way of explanation, presumably because I have it set to MIXED. Looking at it I see I can use a COALESCE instead of the inner IFs, but I'm still unclear why it must be row-based. Thanks, Dan

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[Maria-discuss] install plugin “if not installed”?
by Felipe Gasper 29 Mar '19

29 Mar '19

Hello, Is there any way to install a plugin via SQL but to trap the error that comes up if the plugin is already installed? I’d like to do it without creating a “throwaway” procedure, if that’s possible. Thank you! -Felipe Gasper Mississauga, Ontario

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