今天在升級系統(tǒng)時，連接mysql時報錯了，查看錯誤日志顯示如下：

 Caused by: java.sql.SQLException: null,  message from server: "Host '1' is blocked because of many connection errors; unblock with 'mysqladmin flush-hosts'"
 at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:946) [mysql-connector-java-5.0.4-bin.jar:na]
 at com.mysql.jdbc.MysqlIO.doHandshake(MysqlIO.java:997) [mysql-connector-java-5.0.4-bin.jar:na]
 at com.mysql.jdbc.Connection.createNewIO(Connection.java:2670) [mysql-connector-java-5.0.4-bin.jar:na]
 at com.mysql.jdbc.Connection.<init>(Connection.java:1531) [mysql-connector-java-5.0.4-bin.jar:na]
 at com.mysql.jdbc.NonRegisteringDriver.connect(NonRegisteringDriver.java:266) [mysql-connector-java-5.0.4-bin.jar:na]
 at org.apache.commons.dbcp.DriverConnectionFactory.createConnection(DriverConnectionFactory.java:38) [commons-dbcp-1.2.2.jar:1.2.2]
 at org.apache.commons.dbcp.PoolableConnectionFactory.makeObject(PoolableConnectionFactory.java:294) [commons-dbcp-1.2.2.jar:1.2.2]
 at org.apache.commons.dbcp.BasicDataSource.validateConnectionFactory(BasicDataSource.java:1247) [commons-dbcp-1.2.2.jar:1.2.2]
 at org.apache.commons.dbcp.BasicDataSource.createDataSource(BasicDataSource.java:1221) [commons-dbcp-1.2.2.jar:1.2.2]
 ... 52 common frames omitted

問題分析：

  根據(jù)提示是因為連接數(shù)過多導(dǎo)致許多錯誤的連接，但是在測試時，在本機(jī)通過 mysql -uroot  -proot  -h  192.168.1.2登錄，系統(tǒng)會提示無權(quán)限需要密碼之類的錯誤，在其他主機(jī)192.168.1.3上mysql -uroot  -proot  -h  192.168.1.2登錄成功，個人很奇怪，現(xiàn)在還沒找到原因

解決辦法

 重啟mysql，就OK了