mySQL Error 1040: Too Many Connection

问题:

How to fix these, "SQL Error 1040: Too Many Connection" even I try to put

max_user_connection=500

still "Too many connection"

回答1:

It is worth knowing that if you run out of usable disc space on your server partition or drive, that this will also cause MySQL to retun with this error. If you're sure it's not the actual number of users connected then the next step is to check that you have free space on your MySQL server drive/partition.

回答2:

MySQL: ERROR 1040: Too many connections

This basically tells that MySQL handles the maximum number of connections simultaneously and by default it handles 100 connections simultaneously.

These following reasons cause MySQL to run out connections.

1. Slow Queries

2. Data Storage Techniques

3. Bad MySQL configuration

I was able to overcome this issues by doing the followings.

Open MySQL command line tool and type,

show variables like "max_connections";

This will return you something like this.

+-----------------+-------+
| Variable_name   | Value |
+-----------------+-------+
| max_connections | 100   |
+-----------------+-------+

You can change the setting to e.g. 200 by issuing the following command without having to restart the MySQL server.

set global max_connections = 200;

Now when you restart MySQL the next time it will use this setting instead of the default.

Keep in mind that increase of the number of connections will increase the amount of RAM required for MySQL to run.

回答3:

If you are running out of connections like this, chances are excellent that you are not closing the connections that you have open.

Review code that opens connections and ensure the connections are closed as soon as practical. Typically you want to make use of the using keyword around anything that implements IDisposable (including database connections) to ensure that such objects are disposed as soon as they leave the scope where they are needed.

You can check the current number of active connections with this query:

show processlist

Reference: MySQL show status - active or total connections?

回答4:

You have to change max_connections to increase total permitted connections.

And set max_user_connections back to default 0 => no limit unless you need to limit this per user connections.

MySQL Too many connections

回答5:

In your program you would have opened the connections and left open without closing it.

I faced a same problem and finally identified.

I added this code, after try catch.

finally{
    try {
        rs.close();
        p.close();
        conn.close();
    } catch (SQLException e) {
        // TODO Auto-generated catch block
        e.printStackTrace();
    }
}

回答6:

Try this :

open the terminal and type this command : sudo gedit /etc/mysql/my.cnf

Paste the line in my.cnf file: set-variable=max_connections=500

回答7:

Check if your current running application is still accessing your mysql and has consumed all the DB connections.

So if you try to access mysql from workbench , you will get "too many connections" error.

stop your current running web application which is holding all those db connections and then your issue will be solved.

回答8:

This error occurs, due to connection limit reaches the maximum limit, defined in the configuration file my.cnf.

In order to fix this error, login to MySQL as root user (Note: you can login as root, since, mysql will pre-allocate additional one connection for root user) and increase the max_connections variable by using the following command:

SET GLOBAL max_connections = 500;

This change will be there, until next server restart. In order to make this change permanent, you have to modify in your configuration file. You can do this by,

vi /etc/my.cnf

[mysqld]
max_connections = 500

This article has detailed step by step workaround to fix this error. Have a look at it, I hope it may help you. Thanks.