Search

Language:  
Search for:

Available article translations:

"Too many connections" error in the Parallels Plesk interface

Article ID: 769, created on Oct 6, 2008, last review on Feb 9, 2015

APPLIES TO:
  • Parallels Plesk for Linux/Unix
  • Parallels Plesk for Windows

Symptoms

The following errors occasionally appear in the Parallels Plesk interface:

Unable to connect to database: Too many connections

SQLSTATE[08004] [1040] Too many connections

Cause

This error means that the maximum number of simultaneous connections to the MySQL server has been reached. New connections to the server cannot be established at this time.

Resolution

There are two ways to solve this issue. The first is to increase the connection limit, and the second is determine the cause of the "Too many connections" error and use that information to lower MySQL server usage.

The MySQL server status can be checked using the mysqladmin utility. For example, to find out the number of current connections to the server, use:

# mysqladmin -uadmin -p`cat /etc/psa/.psa.shadow` extended-status | grep Max_used_connections
| Max_used_connections | 11 |

The current connection limit can be found using:

# mysqladmin -uadmin -p`cat /etc/psa/.psa.shadow ` variables | grep 'max.*connections'
| max_connections | 100 |
| max_user_connections | 0

In the above example, the maximum number of connections to the server (max_connections) is set to 100. The maximum number of connections per user (max_user_connections) is zero, which means unlimited. The default MySQL values can be redefined in /etc/my.cnf (/etc/mysql/my.cnf on Debian/Ubuntu). For example:

[mysqld]
set-variable=max_connections=150
set-variable=max_user_connections=20

Restart MySQL after my.cnf has been modified:

/etc/init.d/mysqld restart

Please note: if you set the connection limit to a very high value (more than 300), this may affect server performance. It is better to find and rectify the cause of the unusually high MySQL server usage. You can check which users/requests slow MySQL on all current connections with the following command:

# mysqladmin -uadmin -p`cat /etc/psa/.psa.shadow` processlist

Search words:

New configuration files for the Apache web server were not created due to the errors in configuration templates

plesk mysql import db issues

Website down

Too many connections

PleskFatalException

send db adapter exception

Unable to connect to database

MySQL Said: #1040 - Too many connections

user xxx already has more than 'max_user_connections'

common_func.php3:150

zend db adapter exception

ERROR: Zend_Db_Adapter_Exception: SQLSTATE[08004] [1040] Too many connections (Abstract.php:144)

plesk hang every 120 sec




c81e59b61af9dca603ba03b14aabe968 9f8baf78266b4e54525d1c6bf06305a5 56797cefb1efc9130f7c48a7d1db0f0c 42844a8183c58f5bd71c7d59929707e6

FEEDBACK
Was this article helpful?
Tell us how we may improve it.
Yes No
 
 
 
 
 
 
Server Virtualization
- Parallels Cloud Server
- Parallels Containers for Windows 6.0
- Parallels Virtuozzo Containers
Automation
- Parallels Automation
- Parallels Automation for Cloud Infrastructure
- Parallels Business Automation Standard
- Parallels Virtual Automation
- Parallels Plesk Panel Suite
- Web Presence Builder
- Parallels Plesk Automation
- Parallels Small Business Panel
- Value-added Services for Hosters
- Parallels Partner Storefront
Services & Resources
- Cloud Acceleration Services
- Professional Services
- Support Services
- Training & Certification