能力强的人善于解决问题,有智慧的人善于绕过问题。 区别很微妙,小心谨慎做后者。
全部博文(399)
发布时间:2015-05-02 16:52:18
我们知道 HBase 是基于列族的数据库,数据存在HDFS里。数据横向切分成Region区域,类似sharding。集群中各个slave 叫 区域服务器 Region Server。所有列家族的元数据信息都必须和表的定义存在一块。在HBase 内部, 维护两个目录,分别以表的形式存在HDFS里,它们是 -ROOT- 和 .META. . 它们维护当前最新的区域列表.........【阅读全文】
发布时间:2015-05-02 16:32:27
public class ConcurrentStack { AtomicReference top = new AtomicReference(); public void push(E item) { Node newHead = new Node(item); .........【阅读全文】
发布时间:2015-05-02 16:28:41
Java 内存模型The JMM defines a partial ordering called happens-before on all actions within the program.The rules for happens-before are:Program order rule. Each action in a thread happens-before every action in that thread that comes later in the program order.Monitor lock rule. A.........【阅读全文】
发布时间:2015-05-02 15:39:37
并发程序一定避不开以下三个问题:starvation, deadlock, and race conditionsLimitations of the Actor-Based Model The actor-based model makes it easy to program with isolated mutability, but it does have some limitations. Actors run asynchronously but coordinate by passing messages. The unexpe.........【阅读全文】