mysql问题整理（一）

1. 连接数过多问题解决Too many connections

• 问题

2019-05-17 13:17:14,814 [main] ERROR [com.zaxxer.hikari.pool.HikariPool] HikariPool.java:567 - HikariPool-1 - Exception during pool initialization.
com.mysql.jdbc.exceptions.jdbc4.MySQLNonTransientConnectionException: Data source rejected establishment of connection,  message from server: "Too many connections"

• 解决办法：
  my.cnf配置文件增加如下内容

[mysqld]
max_connections = 1000

2. 常用命令：

• 查询最大连接数
  show variables like "max_connections";
• 临时设置最大连接数
  set global max_connections = 1000;