参考:https://blog.csdn.net/weixin_34293141/article/details/93057113
同事反馈公司的一个java客户端工具运行异常，后台log如下：
2022-12-08 10:52:28 WARN BasicResourcePool:223 - com.mchange.v2.resourcepool.BasicResourcePool$ScatteredAcquireTask@18afde8 -- Acquisition Attempt Failed!!! Clearing pending acquires. While trying to acquire a needed new resource, we failed to succeed more than the maximum number of allowed acquisition attempts (30). Last acquisition attempt exception: java.sql.SQLException: null, message from server: "Host 'VBJVDI00378.test.com' is blocked because of many connection errors; unblock with 'mysqladmin flush-hosts'" at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:1055) at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:956) at com.mysql.jdbc.MysqlIO.doHandshake(MysqlIO.java:1095) at com.mysql.jdbc.ConnectionImpl.createNewIO(ConnectionImpl.java:2031) at com.mysql.jdbc.ConnectionImpl.log重点：
2022-12-08 10:52:28 WARN BasicResourcePool:223 - com.mchange.v2.resourcepool.BasicResourcePool$ScatteredAcquireTask@18afde8 -- Acquisition Attempt Failed!!! Clearing pending acquires. While trying to acquire a needed new resource, we failed to succeed more than the maximum number of allowed acquisition attempts (30). Last acquisition attempt exception:
java.sql.SQLException: null, message from server: "Host 'VBJVDI00378.test.com' is blocked because of many connection errors; unblock with 'mysqladmin flush-hosts'"
根据重点log，可以找到以下几点：
1）问题：
Host 'VBJVDI00378.test.com' is blocked because of many connection errors
同一个ip在短时间连接MySQL服务失败次数超过max_connection_errors参数设定值(默认10)，MySQL则认为是数据库出错，并且阻止了站点的链接。
2）解决方法一：
unblock with 'mysqladmin flush-hosts
终端中执行mysqladmin -uroot -p -h localhost flush-hosts
或者连接数据库后执行flush hosts
mysql>flush hosts
3）解决方法二：
进入数据库将max_connection_errors参数调高，或者修改my.cnf（需要重启MySQL）。
mysql>show variables like '%max_connection_errors%';
mysql>set global max_connect_errors = 1000;
mysql>show variables like '%max_connection_errors%';
注意：配置有master/slave主从数据库的要把主库和从库都修改一遍的。
标签：java,节点,v2,mchange,mysql,锁定,com,BasicResourcePool From： https://www.cnblogs.com/21summer/p/16977662.html