MYSQL太多的连接错误不会消失

I'm getting a MySQL "Too many connections" error in a C++ program running on Ubuntu Linux.

在Ubuntu Linux上运行的c++程序中，我遇到了一个“太多连接”错误。

This is the code that gets the error (it's inside a method that returns the mysql error, if any):

这是获得错误的代码(它位于返回mysql错误(如果有的话)的方法内):

MYSQL connect;
mysql_init(&connect);
if (!mysql_real_connect(&connect,SERVER,USER,PASSWORD,DATABASE,0,NULL,0))
{
    return mysql_error(&connect);
}

This code keeps returning the string "Too many connections."

此代码不断返回字符串“太多连接”。

I'm wondering if this is actually some other error. This program has been working for months before I got this error. When the error first appeared it was because I had run the program against several thousand updates/reads and so yes, it's highly likely that I used up the available connections. The problem is, I can't find a way to release them, if that's what it is.

我想知道这是不是另一个错误。这个程序已经运行了好几个月，我才发现这个错误。当错误第一次出现的时候，是因为我在几千次更新/读取中运行了程序，所以是的，很有可能我耗尽了可用的连接。问题是，我找不到释放它们的方法，如果真的是这样的话。

Here is what I have tried:

以下是我尝试过的:

• FLUSH HOSTS;
• 冲洗主机;
• FLUSH TABLES;
• 刷新表;
• restarting MYSQL
• 重新启动MYSQL
• rebooting the machine altogether
• 完全重新启动机器

It has been over 12 hours since this error first appeared, so if it is the connections then nothing is being reset/released. I would have thought rebooting the machine would have released something.

这个错误第一次出现已经超过12个小时了，所以如果是连接，那么没有什么是重置/释放的。我本以为重启机器会释放一些东西。

2 个解决方案

#1

See C.5.2.7. Too many connections.

看到C.5.2.7。太多的连接。

View all MySQL connections.

查看所有MySQL连接。

 netstat -apn | grep mysql | grep -i established

Tips

• Build and return connection object only when connection pointer is null or connection to DB is unavailable.
• 仅当连接指针为null或连接到DB时才建立和返回连接对象。
• Use one connection pool for the entirety of the session.
• 整个会话使用一个连接池。
• Close the connection at the end of each session and release/clean the connection pointer.
• 在每次会话结束时关闭连接，并释放/清理连接指针。
• Increase max_connections=# in /etc/mysql/my.cnf or restart MySQL with --max_connections=#
• 在/etc/mysql/my.cnf中增加max_connections=#，或者使用—max_connections=#重新启动MySQL

#2

Make sure you close connection when you are done with them.

当你用完它们的时候，一定要保持紧密的联系。

Consider reusing connections or connection pooling.

考虑重用连接或连接池。