Troubleshooting of MySQL errors

Troubleshooting of MySQL errors

🌐 Switch language: EN, 漢字

Installation and Configuration Issues

command not found: mysqldump

1. locate the mysqldump command
   • Key-in the command sudo find / -iname mysqldump for macOS or Linux
   • If you installed
     • XAMPP for macOS : Entire path is /Applications/XAMPP/xamppfiles/bin/mysqldump
     • XAMPP on X disk for Win : Entire path is X:\xampp\mysql\bin\mysqldump.exe
     • MAMP & $ MAMP PRO for macOS : Entire path is /Applications/MAMP/Library/bin/mysqldump
2. input the complete path of mysqldump command
   • old command which caused error mysqldump -h 127.0.0.1 -u root -p --force --single-transaction DATABASE_NAME | pv | gzip -c > DATABASE_NAME.sql.gz
   • new command /Applications/XAMPP/xamppfiles/bin/mysqldump -h 127.0.0.1 -u root -p --force --single-transaction DATABASE_NAME | pv | gzip -c > DATABASE_NAME.sql.gz

Could not start MySQL service on Windows

checklist

1. MySQL Data Directory was allowed to written by NETWORK SERVICE on Windows Server 2008
2. Directory secure-file-priv was allowed to written by NETWORK SERVICE on Windows Server 2008

mysqldump: Got errno 32 on write

Error condition

$ mysqldump -h localhost -u root -p --force --single-transaction --default-character-set=utf8 --quick mytable  | pv | gzip -c > mytable.sql.gz

met the error message:

-bash: pv: command not found
...
mysqldump: Got errno 32 on write

Root cause

• The pv was not installed
• Input the command to check if pv was installed which pv
• install pv by input the command: sudo yum -y install pv

References

• mysqldump: Got errno 32 on write | mysqldump.guru

ERROR 1114 (HY000): The table `TABLE_NAME` is full

Possible solution

• Because the hard disk of partition where MySQL Data Directory located is full or almost full, free some hard disk space.

ERROR 1170: BLOB/TEXT column 'url' used in key specification without a key length

Condition

• SQL syntax when tried to create the new table

DROP TABLE IF EXISTS `my_table`;
/*!40101 SET @saved_cs_client     = @@character_set_client */;
/*!40101 SET character_set_client = utf8 */;
CREATE TABLE `my_table` (
  `id` bigint(20) unsigned NOT NULL AUTO_INCREMENT,
  `title` varchar(500) COLLATE utf8mb4_unicode_ci DEFAULT NULL,
  `url` text COLLATE utf8mb4_unicode_ci NOT NULL,
  `status` tinyint(2) unsigned NOT NULL DEFAULT 1,
  PRIMARY KEY (`job_id`),
  UNIQUE KEY `url` (`url`) USING HASH
) ENGINE=InnoDB AUTO_INCREMENT=3573 DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_unicode_ci;
/*!40101 SET character_set_client = @saved_cs_client */;

Solution: BLOB/TEXT column 'url' used in key specification with a key length e.g. `url`(500)

DROP TABLE IF EXISTS `my_table`;
/*!40101 SET @saved_cs_client     = @@character_set_client */;
/*!40101 SET character_set_client = utf8 */;
CREATE TABLE `my_table` (
  `id` bigint(20) unsigned NOT NULL AUTO_INCREMENT,
  `title` varchar(500) COLLATE utf8mb4_unicode_ci DEFAULT NULL,
  `url` text COLLATE utf8mb4_unicode_ci NOT NULL,
  `status` tinyint(2) unsigned NOT NULL DEFAULT 1,
  PRIMARY KEY (`id`),
  UNIQUE KEY `url` (`url`(500))
) ENGINE=InnoDB AUTO_INCREMENT=3573 DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_unicode_ci;
/*!40101 SET character_set_client = @saved_cs_client */;

ERROR 1205: Lock wait timeout exceeded; try restarting transaction

Solution:

1. SHOW OPEN TABLES WHERE in_use > 0;
2. SHOW [FULL] PROCESSLIST;
3. KILL <process id>;

Related article

• 解決 MySQL ERROR 1205: Lock wait timeout exceeded; try restarting transaction

ERROR 1206: The total number of locks exceeds the lock table size

Message: Error Code: 1206. The total number of locks exceeds the lock table size

Current condition:

• Keywin SHOW VARIABLES LIKE 'innodb_buffer_pool_size';. If it returns 8388608, it means 8388608 bytes ≅ 8MB.

Solution:

• Increase innodb_buffer_pool_size e.g. SET GLOBAL innodb_buffer_pool_size=402653184; (402653184 bytes ~ 400MB. Default value is 8MB.)
• Reduce the size of query data

Further reading:

• innodb - How to change value for innodb_buffer_pool_size in MySQL on Mac OS? - Stack Overflow.
• MySQL :: MySQL 5.7 Reference Manual :: 14.6.3.2 Configuring InnoDB Buffer Pool Size

ERROR 1235: This version of MySQL doesn't yet support 'LIMIT & IN/ALL/ANY/SOME subquery'

Message: ERROR 1235 (42000): This version of MySQL doesn't yet support 'LIMIT & IN/ALL/ANY/SOME subquery'.

Solution: Change the syntax of subquery to column_name BETWEEN start_number to end_number

Further reading:

• MySQL :: MySQL Restrictions and Limitations :: 4 Restrictions on Subqueries

ERROR 1267: Illegal mix of collations (utf8mb4_general_ci,COERCIBLE) and (latin1_swedish_ci,IMPLICIT) for operation 'concat'

Error condition: Tried to concat different type of data e.g. CONCAT(string, int)

Solution: SELECT CONCAT(`string_column`, CONVERT(`int_column`, CHAR)) or SELECT CONCAT(`string_column`, CAST(`int_column` AS CHAR))

ERROR 1305 - FUNCTION MY_TABLE.MY_FUNCTION does not exist

Message: MySQL error 1305 - FUNCTION MY_TABLE.MY_FUNCTION does not exist

Solution: Fix the typo in the function name

ERROR 1690 - BIGINT UNSIGNED value is out of range

Message: MySQL error #1690 (BIGINT UNSIGNED value is out of range)

Solution :

SET sql_mode = 'NO_UNSIGNED_SUBTRACTION';

ERROR 1813: Tablespace for table xxx exists

Message: ERROR 1813 Tablespace for table xxx exists.

Solution

• mysql - Error: Tablespace for table xxx exists. Please DISCARD the tablespace before IMPORT - Stack Overflow

ERROR 1827 (HY000): The password hash doesn't have the expected format. Check if the correct password algorithm is being used with the PASSWORD() function.

Wrong sql query as follows:

CREATE USER 'test'@'localhost' IDENTIFIED BY PASSWORD 'my_password';

Solution: (1) Check if the account was created or not

SELECT User,Host FROM mysql.user;

(2a) If the account was created, set the password for the account.

SET PASSWORD FOR 'test'@'localhost' = PASSWORD('my_password');

(2b) If the account was NOT created, re-create the account.

CREATE USER 'test'@'localhost' IDENTIFIED BY 'my_password';

references

• MySQL :: MySQL 5.7 Reference Manual :: 14.7.1.2 CREATE USER Syntax
• MySQL :: MySQL 5.7 Reference Manual :: 14.7.1.7 SET PASSWORD Syntax
• MySQL :: MySQL 5.7 Reference Manual :: 14.7.1.3 DROP USER Syntax

ERROR 2002: Cannot connect: SQLSTATE[HY000] [2002]

Condition on Cygwin terminal of Windows:

$ mysql -u root -p
Enter password:
ERROR 2002 (HY000): Can't connect to local MySQL server through socket '/var/run/mysql.sock' (2)

$ mysql -h localhost -u root -p
Enter password:
ERROR 2002 (HY000): Can't connect to local MySQL server through socket '/var/run/mysql.sock' (2)

Solution:

• Change -h localhost to -h 127.0.0.1

$ mysql -h 127.0.0.1 -u root -p

• If still not work, reboot the server and restart the MySQL service.

ERROR 2002: SQLSTATE[HY000] [2002] Only one usage of each socket address (protocol/network address/port) is normally permitted

Message: (1) [2002] Only one usage of each socket address (protocol/network address/port) is normally permitted (2) "SQLSTATE[HY000] [2002] 一次只能用一個通訊端位址 (通訊協定/網路位址/連接埠)。" in Chinese

Solution: MySQL/PHP Error:(2002) Only one usage of each socket address (protocol/network address/port) is normally permitted - Stack Overflow

ERROR 2003 (HY000): Can't connect to MySQL server on 'ip'

ERROR 2003 (HY000): Can't connect to MySQL server on 'IP'

Solution:

• Check if the IP is alive

ERROR 2003 (HY000): Can't connect to MySQL server on 'IP' (111 "Connection refused")

Solution:

• Check if the MySQL service is running or not. If not, start the MySQL service.
• Check the firewall rules

ERROR 2003 (HY000): Can't connect to MySQL server on 'IP' (116 "Connection timed out")

Solution:

• Check the configuration of MySQL
  • comment out bind-address = 127.0.0.1 or set to *
  • comment out skip-networking
• Check the permission of MySQL database user.
• Check the firewall rules at (1) your personal computer (2) the server where MySQL service located (3) ISP/VM providers. More on Install MySQL on CentOS 7 | ProfitBricks DevOps Central
  • Check if your IP address was included in the allowed IP address list of firewall rules.
  • Check if your IP address was changed by using What Is My IP Address? services.
• (optional) Monitor the firewall activity. More on How to Track Firewall Activity with the Windows Firewall Log on Win

References:

• Connect to a MySQL database remotely
• Error 2003 - Navicat Wiki
• SQLyog MySQL Admin FAQ - Error no. 2003: Can't connect...

Database and Table Operation Errors

ERROR 1005 (HY000) at line xx: Can't create table 'TABLE_NAME' (errno: 28)

Solutions

• Check if the disk space where mysql data folder located is enough. e.g. Input df -h on Linux
• More on mysql - ERROR 1005 (HY000): Can't create table (errno: 150) - Stack Overflow.

ERROR 1006 (HY000): Can't create database 'DATABASE_NAME' (errno: 28)

Solutions

• Check if the disk space where mysql data folder located is enough. e.g. Input df -h on Linux
• More on ERROR 1006 (HY000) Can't create database (errno: 13) MySQL 5.6.12 - Stack Overflow.

ERROR 1017 - Can't find file: '.\DATABASE\TABLE.frm' (errno: 22 - Invalid argument)

Message: [Err] 1017 - Can't find file: '.\DATABASE\TABLE.frm' (errno: 22 - Invalid argument)

Solutions

• Check the existence of file DATABASE\TABLE.frm. If not, you may need to create the TABLE before executed the MySQL query.
• Check the permission of file DATABASE\TABLE.frm or folder which the file located. unverified

Navicat error: Field doesn't have a default value

[ERR] 1364 - Field 'source' doesn't have a default value

Solution:

• When importing from Excel to a database, if the 'source' field is empty or not specified, it's necessary to assign a value to the 'source' field. Alternatively, modify the field definition to allow the field value to be NULL.

Access and Authentication Errors

ERROR 1044 (42000): Access denied for user 'USER'@'localhost' to database 'DATABASE_NAME'

Message: ERROR 1044 (42000): Access denied for user 'USER'@'localhost' to database 'DATABASE_NAME'

pv file.sql.gz | gunzip | mysql -u USER -p --host=127.0.0.1 --default_character_set utf8 DATABASE_NAME

Solution:

• Check the permission of specified user name & database name

$ mysql -u USER -p --host=127.0.0.1
Enter password:

mysql> use DATABASE_NAME

Message: mysqldump: Got error: 1044: Access denied for user 'USER'@'localhost' to database 'DATABASE_NAME' when doing LOCK TABLES

$ mysqldump -h 127.0.0.1 -u USER -p DATABASE_NAME TABLE_NAME > TABLE_NAME.sql

Solution:

• Add the mysqldump option --skip-lock-tables if you cannot grant the user permissions .

$ mysqldump -h 127.0.0.1 -u USER -p --skip-lock-tables DATABASE_NAME TABLE_NAME > TABLE_NAME.sql

Error!: SQLSTATE[28000]: Invalid authorization specification: 1045 Access denied

Message: Error!: SQLSTATE[28000]: Invalid authorization specification: 1045 Access denied for user 'user'@'localhost' (using password: YES)

Solution:

• If you executed the queryINTO OUTFILE, you need to grant the file permission e.g. GRANT FILE ON *.* TO 'user'@'localhost';.

Related issue: "Error!: SQLSTATE[HY000]: General error: 1290 The MySQL server is running with the --secure-file-priv option so it cannot execute this statement"

ERROR 1049 (42000): Unknown database

Message: ERROR 1049 (42000): Unknown database 'MY_DATABASE_p'

Solution:

• Check the database 'MY_DATABASE_p' is exists
• Check there are no TAB character after database name if you want to connect the database 'MY_DATABASE' when you are using console.

ERROR 1045 (28000): Access denied for user

Message: ERROR 1045 (28000): Access denied for user 'user'@'localhost' (using password: YES)

Solution:

• Check the typo of user name.
• Check the typo of password.
• If you are using the console command, escape the password if it contains special characters e.g. mysql -u root -p'PASSWORD'
• You may need to delete the existing account setting and re-config again.

SQL and Query Errors

Caught exception: SQLSTATE[HY093]: Invalid parameter number: parameter was not defined

Solutions

• Number of question marks is not matched with the number of query values
• The array of query values should not be the associative array. Use sequential array!

ERROR 1054 - Unknown column in 'where clause'

Message: [Err] 1054 - Unknown column 'xxx' in 'where clause'

Solution:

1. check the column name 'xxx' if exists
2. if the column name 'xxx' was computed by the User-Defined Variables. Enclosed the whole query into another parent derived query.

-- The query which met the error message: [Err] 1054 - Unknown column 'rank' in 'where clause'
SELECT semi.*, IF(semi.id = semi.prev, @rank := @rank +1, @rank := 1 ) AS `rank`   
FROM
(
        ...
) semi
WHERE semi.rank <= 10

Enclosed the whole query into another parent derived query.

SELECT final.*
FROM
(
        SELECT semi.*, IF(semi.id = semi.prev, @rank := @rank +1, @rank := 1 ) AS `rank`   
        FROM
        (
                ...
        ) semi
) final
WHERE final.rank <= 10

ERROR 1052 - Column 'column_name' in field list is ambiguous

Message: Error Code: 1052. Column 'column_name' in field list is ambiguous

Cause: Since 'column_name' is present in 2 or more tables ...

Solution: Remain only one table name 'column_name' OR adding the table name alias.

Error!: SQLSTATE[42000]: Syntax error or access violation

Message: Error!: SQLSTATE[42000]: Syntax error or access violation: 1064 You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near ...

Solution:

• SQL syntax debug
• SQL Syntax Check Online, SQL Validator, Instant SQL Compiler Online – EverSQL Not support the PHP: PDO::prepare which the query syntax contains question marks.

ERROR 1366: Incorrect string value

Message: SQLSTATE[HY000]: General error: 1366 Incorrect string value: '\xF0\x9F\x87\xAF\xF0\x9F...' for column 'XXX'

Solution:

• Check the charset of PHP PDO. AND execute set names utf8mb4
• Check the configuration of table
  • CHARACTER SETS (aka 字元集、字符集): utf8mb4
  • COLLATION (aka 定序、字元序): utf8mb4_unicode_ci

ERROR 1070 (42000): Specified key was too long; max key length is 767 bytes

Envoronment: MySQL 5.6

Root cause: "By default, the index key prefix length limit is 767 bytes. See Section 13.1.13, “CREATE INDEX Statement”. For example, you might hit this limit with a column prefix index of more than 255 characters on a TEXT or VARCHAR column, assuming a utf8mb3 character set and the maximum of 3 bytes for each character. When the innodb_large_prefix configuration option is enabled, the index key prefix length limit is raised to 3072 bytes for InnoDB tables that use the DYNAMIC or COMPRESSED row format."

Solution:

• execute SQL query as the following:

SET GLOBAL innodb_file_format = Barracuda;
SET GLOBAL innodb_file_format_max = Barracuda;

• modify the MySQL configuration file

innodb_file_per_table = 1
innodb-file-format = BARRACUDA
innodb-large-prefix = ON
innodb_file_format_max = BARRACUDA

• restart the MySQL server

• execute SQL query as the following:

ALTER TABLE `table_name` ROW_FORMAT=COMPRESSED;

Connection and Network Errors

Error: SQLSTATE[HY000] [2002] No such file or directory

Error message: SQLSTATE[HY000] [2002] No such file or directory

Solutions:

• Modify the host of database from localhost to 127.0.0.1

Resource and Environmental Errors

could not access the mysql log

Version: XAMPP 5.6.15-1 on macOS

Cause:

• the error log only be accessed by the user named mysql

Solution :

find the path to the mysql log
$ ls /Applications/XAMPP/xamppfiles/var/mysql/*.local.err

find the file name of mysql log ex: XXXMacBook-Pro.local.err

set the permission of log
$ sudo chmod 774 /Applications/XAMPP/xamppfiles/var/mysql/XXXMacBook-Pro.local.err

Could not open single-table tablespace file filename.ibd

Version: XAMPP 5.6.15-1 on macOS

Condition: The Mac was shutdown accidentally and the database was not shutdown normally. After reboot the Mac, unable to start the MySQL service.

Possible solution:

1. Edit the MySQL configuration file located: /Applications/XAMPP/xamppfiles/etc/my.cnf
2. Add this line: innodb_force_recovery = 1
3. Try to start the MySQL service
4. If the MySQL service started successfully, edit the MySQL configuration file and mark this line : #innodb_force_recovery = 1
5. Restart the MySQL service

MySQL server has gone away

steps

• Enable the option log_error in MySQL config file e.g. log_error="file_name_of_error_log".
• Example error log located at file_name_of_error_log are as following:

2019-05-23T08:52:19.989876Z 99980 [Note] Aborted connection 99980 to db: 'DB_NAME' user: 'DB_USER' host: 'localhost' (Got a packet bigger than 'max_allowed_packet' bytes)

• Increase the value of max_allowed_packet if the MySQL user has the SUPER privilege.

Error!: SQLSTATE[HY000]: General error

Message: Error!: SQLSTATE[HY000]: General error

Condition: When I used the PHP: PDO

Solutions:

• "You do not use $result = $stmt->fetchAll(); with update or insert queries" .
• You do not use $result = $stmt->fetchAll(); in the query INTO OUTFILE ... .

Error!: SQLSTATE[HY000]: General error: 3 Error writing file xxx.tmp (Errcode: 28 - No space left on device)

Example error message: Error!: SQLSTATE[HY000]: General error: 3 Error writing file 'C:\Windows\SERVIC~2\NETWOR~1\AppData\Local\Temp\MY2713.tmp' (Errcode: 28 - No space left on device)

Condition: Check the disk free space of mysql tmpdir folder

Solutions: Increase the free space of mysql tmpdir folder. Or change the mysql tmpdir folder with another hard disk drive contains more free space.

• Check the current mysql tmpdir folder. Query the syntax SHOW VARIABLES LIKE 'tmpdir';.
  • On Win the default temporary folder is %TMP% = %USERPROFILE%\AppData\Local\Temp.
  • On Linux the default temporary folder maybe is /tmp
• Edit the mysql configuration file

[mysqld]
tmpdir=X:/temp

• Restart the MySQL service

Validation

• Query the syntax SHOW VARIABLES LIKE 'tmpdir'; to validate the modification of mysql configuration file.

errno 41 - Error dropping database

Message: Error dropping database (can't rmdir '.\TABLE_NAME', errno: 41) occurred when I executed DROP DATABASE `TABLE_NAME`;

Solution: phpmyadmin - Error in dropping a database in MySQL (can't rmdir '.\oro', errno: 41) - Stack Overflow

How to resolve "zsh: operation not permitted: xxx.sql"

Error condition

/applications/MAMP/library/bin/mysql -u [USERNAME] -p [DATABASE_NAME] < [PATH_TO_SQL_FILE]

zsh: operation not permitted: PATH_TO_SQL_FILE.sql

Solution: Check Security & Privacy Settings: macOS may block certain actions from the terminal due to security settings. You can try allowing full disk access to the terminal:

• Open System Preferences.
• Go to Security & Privacy.
• Select the Privacy tab.
• Scroll down to Full Disk Access.
• Click the lock icon to make changes (you might need your administrator password).
• Find the Terminal app or iTerm2 or whatever terminal you are using and check the box to allow full disk access.
• Restart your terminal.

Resolve insufficient hard disk space where mysql data located

Err: 解決 MySQL 資料庫所在硬碟空間不足的狀況

PHP Fatal Error: Allowed Memory Size Exhausted when import SQL.GZ file using adminer

solution: Using the naive mysqldump command to generate the backup file. And import the backup by using mysql command.

Miscellaneous Tool-Specific Errors

ERROR: ASCII \0 appeared in the statement, but this is not allowed unless option --binary-mode is enabled and mysql is run in non-interactive mode

Message: ERROR: ASCII '\0' appeared in the statement, but this is not allowed unless option --binary-mode is enabled and mysql is run in non-interactive mode. Set --binary-mode to 1 if ASCII '\0' is expected. Query: ''.

Condition: When I import the sql file and I met the above error message.

Solution: Unzip the file and then import the file again . The sql file is a compressed file. You may use file (command) for recognizing the type of file.

$ file compressed.sql
compressed.sql: gzip compressed data

$ file plain_text.sql
plain_text.sql: UTF-8 Unicode text, with very long lines

Errcode: 13 Permission denied

The message occurred after executed mysqld.exe --datadir=..\data --console when I tried to start the service. (Version of MySQL：5.5.5-10.0.12-MariaDB on Win )

> mysqld.exe --datadir=..\data --console
180430 10:33:38 [ERROR] mysqld.exe: File 'C:\MariaDB_10.0\bin\..\data\aria_log_control' not found (Errcode: 13 "Permission denied")
180430 10:33:38 [ERROR] mysqld.exe: Got error 'Can't open file' when trying to use aria control file 'C:\MariaDB_10.0\bin\..\data\aria_log_control'
180430 10:33:38 [ERROR] Plugin 'Aria' init function returned error.
180430 10:33:38 [ERROR] Plugin 'Aria' registration as a STORAGE ENGINE failed.
180430 10:33:38 [Note] InnoDB: Using mutexes to ref count buffer pool pages
180430 10:33:38 [Note] InnoDB: The InnoDB memory heap is disabled
180430 10:33:38 [Note] InnoDB: Mutexes and rw_locks use Windows interlocked functions
180430 10:33:38 [Note] InnoDB: Compressed tables use zlib 1.2.3
180430 10:33:38 [Note] InnoDB: Not using CPU crc32 instructions
180430 10:33:38 [Note] InnoDB: Initializing buffer pool, size = 4.0G
180430 10:33:38 [Note] InnoDB: Completed initialization of buffer pool
180430 10:33:38 [ERROR] InnoDB: .\ibdata1 can't be opened in read-write mode
180430 10:33:38 [ERROR] InnoDB: The system tablespace must be writable!
180430 10:33:38 [ERROR] Plugin 'InnoDB' init function returned error.
180430 10:33:38 [ERROR] Plugin 'InnoDB' registration as a STORAGE ENGINE failed.
180430 10:33:38 [Note] Plugin 'FEEDBACK' is disabled.
180430 10:33:38 [ERROR] Unknown/unsupported storage engine: innodb
180430 10:33:38 [ERROR] Aborting

180430 10:33:38 [Note] mysqld.exe: Shutdown complete

Solutions:

Open the command line with administrative privileges. (How to: How to Open the Command Prompt as Administrator in Windows 8 or 10)

Navicat error: Import data mismatch

Error:

When importing an Excel file into a MySQL database using Navicat, there is an issue with the total number of records not matching. Solution: Delete blank rows and check for any duplicate primary key data.

Solution:

• 解決 NaviCat 匯入 Excel 檔案到資料庫，出現資料總筆數不一致的問題 (written in Mandarin)

Navicat error: [Exp] OLE error 800A03EC

error message:

[Msg] [Exp] Export to - test.xlsx
[Err] [Row1048576] [Exp] OLE error 800A03EC
[Err] [Row1048577] [Exp] OLE error 800A03EC
[Err] [Row1048578] [Exp] OLE error 800A03EC
[Err] [Row1048579] [Exp] OLE error 800A03EC

cause:

• Rows count of results exceed the limit of Microsoft Excel Worksheet size: 1,048,576 rows

solution:

• LIMIT the rows of MySQL query

References

Troubleshooting of ...

• Troubleshooting of Excel errors

• PHP, cUrl, Python, selenium, HTTP status code errors

• Database: SQL syntax debug, MySQL errors, MySQLTuner errors or PostgreSQL errors

• Troubleshooting of regular expression

• HTML/Javascript: Troubleshooting of javascript, XPath

• Software: Mediawiki, Docker, FTP problems, online conference software

• Test connectivity for the web service, Web Ping, Network problem, Web user behavior, Web scrape troubleshooting

Template

• Bug report template