我正在使用Java+MySql。我正在尝试添加批量数据(大约4000万条记录)。我的应用程序可以很好地处理几十万条记录,但是在那之后,它开始给我以下异常:
Exception in thread "main" com.mysql.jdbc.exceptions.jdbc4.CommunicationsException: Communications link failure
The last packet sent successfully to the server was 0 milliseconds ago. The driver has not received a
我正试图在我的VPS服务器上安装openfire。服务已经启动并运行。我被困在openfire服务器的数据库配置步骤中。我已经在mysql服务器上创建了openfire数据库,并导入了模式。但是,当我试图在基于web的安装程序中使用这些设置时,我会得到以下错误:
A connection to the database could not be made. View the error message by opening the "/logs/error.log" log file, then go back to fix the problem.
设置如下: JDBC驱动
我正在尝试以非常高的速度在mysql中进行批量插入。我想尝试一下rewriteBatchedStatements配置选项,因为我读到它会对性能产生重大影响。然而,当我添加这个选项时,我得到了以下异常:
java.lang.NullPointerException
at com.mysql.jdbc.PreparedStatement.computeMaxParameterSetSizeAndBatchSize(PreparedStatement.java:1694)
at com.mysql.jdbc.PreparedStatement.computeBatchSize(PreparedSta
当我试图查询数据库并将结果写入文件时,会收到此错误。以前从来没有发生过。
java.sql.SQLException:错误写入文件'/tmp/MYwADPLw‘(错误代码: 28)
在com.mysql.jdbc.SQLError.createSQLException(SQLError.java:946) at com.mysql.jdbc.MysqlIO.checkErrorPacket(MysqlIO.java:2870) at com.mysql.jdbc.MysqlIO.sendCommand(MysqlIO.java:1573) at com.mysql.jdbc.Mysq
当我在安装Ganib之后启动Tomcat7时,我会进入注册页面,但是当我尝试注册时,我会得到一个空白页,并将以下内容写入日志:
=========== checking limit ==========
Class not found exception
Is Valied 1
Error in registration process creation
com.mysql.jdbc.exceptions.jdbc4.MySQLIntegrityConstraintViolationException: Column 'USER_ID' cannot be null
a
在Maven项目中。当我第一次设置XAMPP和MySQL时,效果很好。但在mysql-connector-java-8.0.20.zip或mysql-connector-java-8.0.20.jar.的NetBeans中,我无法连接到MySQL,也无法创建连接driver="com.mysql.cj.jdbc.Driver"和url="jdbc:mysql://localhost:3306/mysql"
当我要向MySQL添加新连接时,它会显示错误消息,
Cannot establish a connection to jdbc:mysql://loc
当我为表同步运行spark应用程序时,错误消息如下所示:
19/10/16 01:37:40 ERROR Executor: Exception in task 0.0 in stage 3.0 (TID 51)
com.mysql.cj.jdbc.exceptions.CommunicationsException: Communications link failure
The last packet sent successfully to the server was 0 milliseconds ago. The driver has not received any packet
我有以下错误:
com.mysql.jdbc.exceptions.jdbc4.MySQLSyntaxErrorException: Access denied for user 'root'@'%' to database 'GUEST_BOOK'
at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstr
我正在使用jmeter对使用CloudSQL的GAE服务进行压力测试,我得到了间歇性的通信链路故障异常。
我尝试过使用直接连接和连接池,在这两种情况下我都看到了异常。随着每秒请求数的增加,异常也会增加。
请注意,我们使用的是最高层的云sql、D32,测试结果远低于最大3200个连接数。
下面是一个供参考的堆栈跟踪:
The last packet sent successfully to the server was 0 milliseconds ago. The driver has not received any packets from the server.
at sun.refle