In this tutorial i will show you how to fix 'MySQL not running but lock file exists' error
MySQL (Percona Server) is not running, but lock file (/var/[FAILED]sys/mysql) exists
First you need to delete the lock file
Be sure that there is no multiple MySQL services running, check MySQL processes and kill them Continue reading
phpMyAdmin is a free web application which will make it easier working with MySQL, it will provide simple backup,restore and other MySQL GUI features, in this tutorial i will show you how to install phpMyAdmin on Centos, download phpMyAdmin, and this can be applies to localhost phpMyAdmin too.
Install phpMyAdmin on Centos 7
In this article i will be installing phpMyAdmin on CentOS 7, this can work on RHEL 7 and other flavors too.
Is MySQL Master and Slave are in sync ?
In this tutorial i will be sharing both queries to find out MySQL slave status and basics of tracing root cause.
Check MySQL slave status
- Connect to MySQL slave database 'ex.: mysql -u user -p ....etc'
- Run below queries
SHOW SLAVE STATUS\G
MySQL Error: error: 11
If you are getting error: 11 while trying to start or restart the mysql service this might be a problem of having multiple mysql processes locking the ibdata.
To fix this issue you need first to list all the mysql process that might be running in the background and locking it. Continue reading
Create a MySQL user in the destination server and give the required grants.
You want to connect to MySQL server from ServerA (192.168.10.20) to MySQL ServerB (192.168.10.40) Continue reading
SQLSTATE  Access denied MySQL Error
These kind of errors can appear either in the application side log, screen or in MySQL error log.
Check MySQL Error Log
#1 Find error log path , to find your error long you can follow one of the below methods: Continue reading
Getting MySQL ERROR 1064 While Restoring a Backup Which was Created using MySQL
In this post we will be addressing the MySQL error 1064 and show the causes which can lead to this error, usually this error appears when trying to restore a backup and it will be a syntax in the sql which can be fixed manually by editing the sql or going through the below fixes.
Getting ERROR 1064 (42000) while restoring a MySQL dump sql file. Continue reading
Determining the size of MySQL database
Determining the size of specific MySQL database can be done in so many way, you can do it from the Linux file system perspective or from MySQL.
The most accurate way to find MySQL database size recommended by Percona is by checking the information_schema and this can be done by running the following query (Replace db_name with the database name you want to investigate) :
Database size in GB:
SELECT table_schema "Database Name", SUM( data_length + index_length)/1024/1024/1024 "Database Size (GB)" FROM information_schema.TABLES where table_schema = 'db_name';
Database size in MB:
SELECT table_schema "Database Name", SUM( data_length + index_length)/1024/1024 "Database Size (MB)" FROM information_schema.TABLES where table_schema = 'db_name';
Sqlstate error usually happens when there is a problem connecting to the database, you can troubleshoot this by checking the connectivity from the source web-server to the database and the firewall rules if it's on a different server than the web server.
Ping the database
If you are not getting a reply or it's not resolving then maybe you need to check the dns or hosts file to be sure that it's pointed to the right ip
Check the firewall and if the port is opened between both server
nmap -sS -O server_name or IP_Address
You should see something like:
3306/tcp open mysql
Or different ports and service if it's ms-sql, if the port is not there or closed, then you need to open the firewall.
If you are getting that error:
Error 1114 (HY000) at line : The table " is full
You can try one of the below methods:
Check the 'innodb_data_file_path' limit by
SHOW GLOBAL VARIABLES LIKE 'innodb_data_file_path';
This should show anything above the following: Continue reading