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文章列表
导读: 这是一篇介绍Java Security能做什么的文章。很遗憾,它不会告诉你怎么去做。 本文相关的JDK版本是JDK7,当然,仍适用于JDK6。   Java平台(Java运行时环境,即JVM + Java API) 在多个层面上提供了security机制。   Java Language ...
最后更新于: 2013/7/1 --------------------------------------------------------------------------------------------------------------- 本文主要介绍软件层面的性能调优。故,在此之前,请检查硬件状况。硬盘推荐SSD,一般SATA即可。网络千兆以上。可以安装Ganglia等工具,检查各节点的各硬件的运作状态:CPU,Memo,网络等等。   一、调整参数 入门级的调优可以从调整参数开始。投入小,回报快。   1. Write Buffer Size 快速配置 ...
全名叫Unlimited Strength Java(TM) Cryptography Extension (JCE) Policy Files for the Java(TM) Platform。本质是Java的policy文件(Java policy 相关请参见我的其他博文)。一般JDK内置的policy文件会对加密算法所使用的KEY的长度有所限制,一般限制在128bits(Triple-DES和RSA除外)。所以我们需要部署Unlimited Strength JCE Policy文件,来解开限制。   现象 我们可以用如下代码来做个小测试。   KeyGen ...
http://www.infoq.com/articles/no-reliable-messaging   Author: Marc    A received view in SOA and Web Services is the need for reliable messaging. Reliable messaging is the guarantee that a message sent by a sending application is indeed received at the other end, and received only once. One of ...
使用栈来实现,可以处理运算优先级。 使用自然四则运算表达式即可,如:4+(3*(3-1)+2)/2。无需把表达式先转换为逆波兰等形式。   package com.joshua.cal; import java.util.Collections; import java.util.HashMap; import java.util.HashSet; import java.util.LinkedList; import java.util.List; import java.util.Map; import java.util.Set; import java.ut ...
Wow, LZ4 is fast! I’ve been doing some experiments with LZ4 recently and I must admit that I am truly impressed. For those not familiar with LZ4, it is a compression format from the LZ77 family. Compared to other similar algorithms (such as Google’s Snappy), LZ4’s file format does not allow for ver ...
Google Brain之父,斯坦福大学教授Andrew Ng带来的机器学习课程。 另注:Andrew同时也是coursera的创始人。 https://www.coursera.org/course/ml   About the Course Machine learning is the science of getting computers to act without being explicitly programmed. In the past decade, machine learning has given us self-driving cars, pract ...
本文介绍在Java平台上如何访问受限资源,比如读写一个文件。我们通过配置policy文件来使得一个未签名的applet访问系统的受限资源。本文主要由以下内容组成: 对于Applet的限制 如何配置Policy文件 如何使Policy生效   对于Applet的限制 Java插件使用Security Manager来防止病毒通过applet侵入你的系统。如果未签名的applet想访问某个系统资源,Security Manager会检查对应的权限是否已经授权,未授权的applet无法访问系统资源。授权需要配置policy文件中的entry。   Oracle官方提供了一个ap ...

Presentations

Architecting for High Availability http://www.infoq.com/presentations/architecting-high-availability   The Fundamentals of JVM Tuning http://www.infoq.com/presentations/jvm-tuning   Large-Scale Continuous Testing in the Cloud http://www.infoq.com/presentations/Continuous-Testing-Build-Cloud ...
Apache Hadoop YARN – ResourceManager As previously described, ResourceManager (RM) is the master that arbitrates all the available cluster resources and thus helps manage the distributed applications running on the YARN system. It works together with the per-node NodeManagers (NMs) and the per-appl ...
Apache Hadoop YARN – NodeManager The NodeManager (NM) is YARN’s per-node agent, and takes care of the individual compute nodes in a Hadoop cluster. This includes keeping up-to date with the ResourceManager (RM), overseeing containers’ life-cycle management; monitoring resource usage (memory, CPU) o ...
本节按字母顺序 (N-Z) 列出了 Kerberos 命令、Kerberos 守护进程、PAM 框架、GSS 接口、NFS 服务和 Kerberos 库的常见错误消息。   No credentials cache file found 原因: Kerberos 无法找到凭证高速缓存 (/tmp/krb5cc_uid)。 解决方法: 请确保该凭证 ...
本节按字母顺序 (A-M) 列出了 Kerberos 命令、Kerberos 守护进程、PAM 框架、GSS 接口、NFS 服务和 Kerberos 库的常见错误消息。   All authentication systems disabled; connection refused 原因: 此版本的 rlogind 不支持任何验证机制。 解决方法: 请确保调用的 rlogind 带有 -k 选项。   Another authentication mechanism must be used to access this host 原因: 无法进行验证。 解决方法: ...
TPC-H是数据库/数据仓库选型决策用的benchmark。它是世界公认的benchmark,由一套面向业务的数据查询和并发数据更新组成。百度文库里有个文档写的还不错。   Jia, Yuntao在HIVE-600中提交了TPC-H的hive driver。Driver由shell脚本作为bootstrap,由一系列HQL文件组成,总共22个benchmark。Driver中并不包含原始数据,需要使用TPC-H的DBGEN生成。
Java MakefileA simple replacement for Ant Version 4.4, January 2011Geotechnical Software ServicesCopyright © 1999 - 2011   This document is available at http://geosoft.no/development/javamake.html Abstract: A cross-platform (MS-Windows, Linux, UNIX) makefile for a wide range of programming l ...
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