Symptoms
-
The following error message appears in the Plesk interface or during Plesk migration process:
Unable to tướng connect to tướng database: Too many connections
SQLSTATE[08004] [1040] Too many connections
ODBC error #HY000: [unixODBC][ma-3.0.8]Too many connections
-
Websites fail to tướng load with the error:
Error Establishing a Database Connection
-
Plesk license installation fails with the error:
Incorrect ServerInfo format (Error code: 2)
exit status 1
Cause
The maximum number of simultaneous connections to tướng the MySQL databases has been reached and new connections to tướng the server cannot be established.
Resolution
For Plesk on Linux
Note: On Linux server with MySQL installed, the max_connections
limit cannot be higher kêu ca 214, unless the solution from this KB article is applied.
# Automatic Solution
-
Connect to tướng the Plesk server via SSH.
-
Download the script that will mix the MySQL parameter
max_connections
to tướng 300:# wget https://raw.githubusercontent.com/plesk/kb-scripts/master/mysql-max-connections/mysql-max-connections.sh
-
Make the script executable:
# chmod +x mysql-max-connections.sh
-
Execute the script:
# ./mysql-max-connections.sh
Note: If the automatic solution did not help, apply the manual solution below.
# Manual Solution
-
Connect to tướng the Plesk server via SSH.
-
Find the current
max_connections
value:# plesk db "SHOW VARIABLES LIKE 'max_connections'"
+-----------------+-------+
| Variable_name | Value |
+-----------------+-------+
| max_connections | 151 |
+-----------------+-------+ -
Open the MySQL configuration tệp tin
my.cnf
in a text editor. In this example, we are using the vi editor:-
on CentOS/RHEL-based distributions
# vi /etc/my.cnf
-
on Debian/Ubuntu-based distributions
# vi /etc/mysql/my.cnf
-
-
Increase the number of connections by adding this directive under the
[MySQLD]
section:[mysqld]
max_connections=300 -
Save the changes and close the tệp tin.
-
Restart MySQL/MariaDB service to tướng apply the changes using one of these commands:
# service mysql restart
# service mariadb restart
For Plesk on Windows Server
-
Connect to tướng the Plesk server via RDP.
-
Open the MySQL configuration tệp tin
%plesk_dir%DatabasesMySQLmy.ini
in a text editor. -
Increase the number of connections by adding this directive under the
[MySQLD]
section (the mặc định value is 300):[MySQLD]
max_connections=300 -
Save the changes and close the tệp tin.
-
Restart the MySQL/MariaDB service Plesk Management Service using Windows Plesk Services Monitor