MySQL5.5 中引入了 metadata lock. 顾名思义,metadata lock 不是为了保护表中的数据的,而是保护 database objects(元数据)的.包括表结构.schema.存储过程.函数.触发器.mysql的调度事件(events). 要理解 metadata lock 最重要的一点就是:将 metadata lock放到数据库事务的语义中来理解.metadata lock 的作用就是当一个事务在执行时,事务涉及到的所有元数据(metadata,也就是 dat

MySQL5.5 中引入了 metadata lock. 顾名思义,metadata lock 不是为了保护表中的数据的,而是保护 database objects(元数据)的.包括表结构.schema.存储过程.函数.触发器.mysql的调度事件(events). 要理解 metadata lock 最重要的一点就是:将 metadata lock放到数据库事务的语义中来理解.metadata lock 的作用就是当一个事务在执行时,事务涉及到的所有元数据(metadata,也就是 datab

1.innodb_lock_monitor:打开锁信息的方式 mysql> create table innodb_lock_monitor(id int) engine=InnoDB; Query OK, rows affected, warning (2.29 sec) mysql> begin work; Query OK, rows affected (0.00 sec) mysql ; Query OK, row affected (0.07 sec) Rows matched: C

<pre name="code" class="html">mysql 锁表: 隔离级别使用RR: mysql> SELECT @@GLOBAL.tx_isolation, @@tx_isolation; +-----------------------+-----------------+ | @@GLOBAL.tx_isolation | @@tx_isolation | +-----------------------+-----------

作者Alistair Cockburn, Crystal Clear的7个成功要素,写得挺好. 敏捷方法的关注点,大家可以参考,太激动所以转载了. 原文:http://www.informit.com/articles/article.aspx?p=345009 Property 1. Frequent Delivery The single most important property of any project, large or small, agile or not, is that

Dubbo(http://dubbo.io/) 是阿里的开源的一款分布式服务框架.而Spring Boot则是Spring社区这两年致力于打造的简化Java配置的微服务框架. 利用他们各自优势,配置到一起,可以帮助我们构建出非常优秀的微服务. 配置Maven 使用的Dubbo的一般都是大型项目,maven项目构建也会使用parent节点,Spring Boot考虑到了这种情况,提供了dependencyManagement的方式,引入Spring Boot的包. <dependencyManag

Android PopupWindow Dialog 关于 is your activity running 崩溃详解 [TOC] 起因 对于 PopupWindow Dialog 需要 Activity 作为容器,并于其生命周期联系在一起.在Activity 还没有初始化完成时,此时我们调用 PopupWindow Dialog 的show()方法就会抛出异常: throw new WindowManager.BadTokenException("Unable to add window --

学习Java Servlet时,从Wrox上下载了示例代码,准备run/debug时发现以下错误: Error running Tomcat 8.5.8: Unable to open debugger port (127.0.0.1:49551): java.net.SocketException "Socket closed" /Users/GuQiang/Tomcat/apache-tomcat-8.5.8/bin/catalina.sh stopUsing CATALINA_B

执行下面的命令问题解决: # teamviewer --daemon enable enable Sat Jan :: CST Action: Installing daemon () for 'upstart' ... installing /etc/init/teamviewerd.conf (/opt/teamviewer/tv_bin/script/teamviewerd.RHEL.conf) semodule --install=/opt/teamviewer/tv_bin/scrip

sh-4.1# /etc/init.d/mysqld status ERROR! MySQL is not running, but lock file (/var/lock/subsys/mysql) exists sh-4.1# /etc/init.d/mysqld start Starting MySQL. ERROR! The server quit without updating PID file (/data1/mysql/mysql.pid). sh-4.1# rm mysql

1.问题:Errors occurred during the build. Errors running builder 'JavaScript Validator' on project 2.解决: 步骤: 1) 选择项目. 2)右键, 点击[Properties]. 3) 点击[Builders],取消右面的[JavaScript Validator].

The network bridge on device VMnet0 is not running. The virtual machine will not be able to communicate with the host or with other machines on your network. Virtual device Ethernet0 will start disconnected 原因在于原来的VMware Bridge Protocol服务丢失了! 解决方法如下:

/etc/init.d/mysql status提示ERROR! MySQL is running but PID file could not be found先打印MYSQL进程ps aux | grep mysql然后KILL进程kill -9 pid1 pid2 …再启动MYSQL/etc/init.d/mysql start再检查mysql运行状态/etc/init.d/mysql status

错误提示: psql: could not connect to server: No such file or directory Is the server running locally and accepting connections on Unix domain socket "/var/run/postgresql/.s.PGSQL.5432"?  出现该问题的很多,以下是目前碰到的几种情况,之后碰到继续补充:  1.删除了/tmp路径中的.s.PGSQL.5432 与.

maven编译项目时出错,提示信息如下: [ERROR] Failed to execute goal org.apache.maven.plugins:maven-compiler-plugin:3.1:testCompile (default-testCompile) on project springside-core: Compilation failure [ERROR] No compiler is provided in this environment. Perhaps you

Android Studio方便好用,但是Android Studio Gradle Build Running很慢 解决方法: C:\Users\你的用户名\.gradle 目录下新建一个文件名为 gradle.properties 的文件 文件的内容为: org.gradle.daemon=true

问题出现: 每周一需要备份一次数据库,即从服务器MySQL导出sql文件,再导入到我机器上虚拟机的MySQL里.但是今天早上连不上,我进入控制台用#service mysqld start强行启动,报Another MySQL daemon already running with the same unix socket错. 问题解决: 按关键字在百度查找,找到 http://wenku.baidu.com/link?url=MMZfHWxyl9maR_NP8OOSnRhnDzh5BhK82u

No compiler is provided in this environment. Perhaps you are running on a JRE ra,有需要的朋友可以参考下. 控制台输出的错误信息如下: [INFO] Scanning for projects... [INFO] [INFO] Using the builder org.apache.maven.lifecycle.internal.builder.singlethreaded.SingleThreadedBuild

报错如下: 1. Unable to obtain lock on /usr/local/odrive/odrive_chen/Middleware/user_projects/domains/oimchen_domain/servers/AdminServer/tmp/AdminServer.lok. Server may already be running2.weblogic.management.ManagementException: Unable to obtain lock on

Running Time Limit: 1000MS   Memory Limit: 65536K Total Submissions: 5652   Accepted: 2128 Description The cows are trying to become better athletes, so Bessie is running on a track for exactly N (1 ≤ N ≤ 10,000) minutes. During each minute, she can