聚沙成塔-小哈的记事薄

Tools and Tips to Diagnose Performance Issues

分析性能问题的一些工具和建议

好东西，赶紧拉下来，介绍的太完整了，从内存调整到各种池大小优化。developerworks上都难得一见的完整调优案例。

原文链接：http://www.ibm.com/developerworks/cn/websphere/techjournal/0909_blythe/0909_blythe.html

IBM WebSphere Application Server 是一种可靠的企业级应用服务器，它提供了一组核心组件、资源和服务，供开发人员在应用程序中使用。每个应用程序都具备特有的需求，并且经常采用截然不同的方式使用应用服务器的资源。为了提供高度灵活性并支持这种广泛的应用程序，WebSphere Application Server 提供了一组全面的参数来帮助您增强对应用程序的调优。

应用服务器已经为最常用的调优参数设置了默认值，以确保能为最广泛的应用程序提供开箱即用的性能改善。但是，由于任意两个应用程序都不可能采用完全相同的方式来使用应用服务器，因此无法确保一组调优参数能适用于所有应用程序。这也突显了对应用程序执行有重点的性能测试和调优的重要性。

本文将讨论在 WebSphere Application Server V7.0（和之前发行版）中最常使用的一些参数，以及对它们进行调优的方法。与其他相关文章提供的调优建议不同，本文将使用 Apache DayTrader Performance Benchmark Sample 案例研究作为本文的上下文。借助 DayTrader 应用程序，您可以清楚地确定所使用的主要服务器组件，对这些区域进行重点调优，并观察各种调优更改所带来的收益。

在继续阅读之前，需要记住关于应用服务器性能调优的一些事项：

• 提高性能经常会牺牲应用程序或应用服务器的一些特性或功能。在计算性能调优更改时应该仔细考虑性能和特性之间的权衡。
• 应用服务器之外的一些因素有时会影响性能，包括硬件和操作系统配置、系统中运行的进程、后端数据库资源的性能、网络延迟等等。您在自己执行性能评估时，必须将这些因素考虑在内。
• 此处讨论的性能改善仅针对 DayTrader 应用程序，并且特定于此处描述的工作负载组成及所支持的硬件和软件栈。您通过本文介绍的调优更改实现的应用程序性能提升肯定会有所不同，并且应该通过您自己的性能测试进行评估。

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如果你想订阅这个邮件列表，发送邮件到wsehelp@us.ibm.com即可，邮件名称标注“subscribe WebSphere Application Server”

WebSphere Application Server Customer,
As a valued WebSphere Application Server customer who has contacted technical support, we are hoping you will find this information useful.
This note contains links to WebSphere Application Server technical support documents and information that can help you obtain value from your software. It is intended to help you to be proactive in your support and administration of WebSphere Application Server.

• • • Learn more about the portal
    • View the demo videos
    • Access the IBM Support Portal and sign in with your IBM ID and password

  1. Don’t be caught by surprise – try the IBM Support Portal today
  On January 6 the new IBM Support Portal, a unified, centralized view of all technical support tools and information for all IBM software, replaces the existing software product support pages. You can tailor the Support Portal to suit your needs, focusing on the software and hardware products you care about and organizing the pages to reflect the way you work. The portal makes it fast and easy to find the information or tools you need to prevent and resolve problems.We hope you can take a few minutes to fill out a short questionnaire that evaluates the IBM Support Portal in comparison to the existing IBM support website pages. We appreciate your feedback!
  2. IBM WebSphere Application Server Migration Toolkit
  The IBM WebSphere Application Server Migration Toolkit helps organizations migrate applications from other application servers to IBM WebSphere Application Server. WebSphere Application Server, a Java EE 5 certified, EJB 3.0 supported technology-based application platform, is a key part of the IBM Smart SOA Application Foundation that delivers the innovation and performance essential to cost-effectively build, deploy and manage robust SOA applications.
  http://www.ibm.com/developerworks/websphere/downloads/migration_toolkit.html
  3. developerWorks: WebSphere Application Server security
  This page of essential resources contains hints, tips, and valuable guidance to help you configure and use WebSphere Application Server security more effectively, and to design and develop your WebSphere Application Server solutions in ways that will make them more secure. Also included is information on the security environment in which WebSphere Application Server resides.
  http://www.ibm.com/developerworks/websphere/zones/was/security/
  4. Follow WebSphere Support on Twitter
  A list of available Twitter accounts for WebSphere Support.
  http://www.ibm.com/support/docview.wss?rs=180&uid=swg21410956
  5. WebSphere Application Server Feature Pack for XML
  The IBM WebSphere Application Server V7 Feature Pack for XML delivers updated XML programming model standards to help improve developer productivity and address new application development scenarios.
  http://www.ibm.com/software/webservers/appserv/was/featurepacks/xml/
  6. IBM Support Assistant – helping you simplify support
  If you haven’t tried the IBM Support Assistant yet, use the Quick Start Guide to find out what you’re missing! Save time with automated collectors and over 20 robust problem determination tools. IBM Support Assistant can be customized for over 350 IBM software products. The ISA Lite offering lets you quickly use the accurate, automated data collection capability. Download the workbench or ISA Lite to simplify support and save time. Not sure which one you need? Use the handy chart on the page to help you decide.
  7. The Support Authority: Know what your Web application is really doing
  The IBM Monitoring and Diagnostic Tools for Java – Health Center is a lightweight tool that monitors IBM virtual machines for Java with minimal performance overhead. It provides live information and recommendations about classes being loaded, the virtual machine environment, garbage collection, locking, and profiling. This article introduces you to the Health Center and shows an example of how it can be used to check the impact of a source code change in a Web application.
  http://www.ibm.com/developerworks/websphere/techjournal/0911_supauth/0911_supauth.html
  8. The Support Authority: Analyze memory management problems with the Memory Dump Diagnostic for Java (MDD4J)
  The Memory Dump Diagnostic for Java (MDD4J) tool helps you diagnose memory leaks and other excessive memory consumption problems in applications running in IBM Java Virtual Machines (JVMs). This article introduces you to MDD4J and shows you how to use its sophisticated analysis engine and user interface to peer into the Java heap so you can see which objects are consuming the most amount of memory.
  http://www.ibm.com/developerworks/websphere/techjournal/0909_supauth/0909_supauth.html
  9. One plug-in config to handle multiple Portal Applications in multiple Portal Clusters
  I have different Portal applications running in 2 different Portal Clusters. I want to use only 1 IBM HTTP Server Web server to route requests correctly for both applications in both clusters. How can I configure the Web server plug-in to accomplish this?
  http://www.ibm.com/support/docview.wss?rs=180&uid=swg21397408
  10. Web server plug-in routing to SAME application in DIFFERENT clusters
  If I install the same Web application into more than one WebSphere Application Server cluster, is it possible to configure the Web server plug-in to properly route requests to the application in both clusters?
  http://www.ibm.com/support/docview.wss?rs=180&uid=swg21331062
  11. IBM Service Integration Bus Destination Handler, Version 1.1
  A tool to view, move, copy, delete, save and restore messages in the default messaging provider for IBM WebSphere Application Server versions 7.0, 6.1, and 6.0.
  http://www.ibm.com/support/docview.wss?rs=180&uid=swg24021439
  12. Solution for installing 32-bit Java SDK fix packs on IBM HTTP Server V7.0 using Update Installer 7.0.0.5 and earlier
  For most operating systems and architectures, you should install the 32-bit Java SDK fix packs for IBM HTTP Server V7.0, even if that IBM HTTP Server was installed from the 64-bit Supplemental installation image. However, due to a defect in the process, Update Installer V7.0.0.5 and earlier will not allow you to install the 32-bit Java SDK fix pack, and will erroneously allow you to install the 64-bit Java SDK fix pack instead. This technote explains how to address this problem.
  http://www.ibm.com/support/docview.wss?rs=180&uid=swg21395882

  1. End of Support – WebSphere Application Server V5.1
  WebSphere Application Server V5.1 content has been “EOSed”. IBM ended the support for IBM WebSphere Application Server version 5.1 products in September 2008. WebSphere Application Server V5.1 content, including product documentation, technotes, Fix Packs and Interim Fixes, is now available from the WebSphere End of Support Products Web site.
  http://www.ibm.com/support/docview.wss?rs=3680&uid=swg21410048
  2. Recommended fixes for WebSphere Application server
  A comprehensive list of recommended, generally available (GA) fixes for IBM WebSphere Application Server releases.
  http://www.ibm.com/support/docview.wss?rs=180&uid=swg27004980
  3. Fixes by version for WebSphere Application Server
  A comprehensive list of generally available (GA) fixes for WebSphere Application Server releases.
  http://www.ibm.com/support/docview.wss?rs=180&uid=swg27006899
  4. Feature packs by version for WebSphere Application Server
  A comprehensive list of generally available (GA) feature packs for WebSphere Application Server
  http://www.ibm.com/support/docview.wss?rs=180&uid=swg27008534
  5. Detailed system requirements for WebSphere Application Server
  Identifies the supported software options by operating system for the WebSphere Application Server product.
  http://www.ibm.com/support/docview.wss?rs=180&uid=swg27006921
  1. WebSphere Application Server Administration Using Jython
  Utilizing Jython scripting, you can dramatically reduce the effort, resources, and expense associated with managing WebSphere Application Server. WebSphere Application Server Administration Using Jython will show you how. The first start-to-finish guide to Jython scripting for WebSphere administration, this book’s practical techniques and downloadable scripts can help you improve efficiency, repeatability, and automation in any WebSphere environment.
  *Using coupon code IBM9527 provides you a 35% discount AND Free Shipping!
  http://www.ibmpressbooks.com/bookstore/product.asp?isbn=0137009526
  2. Join us for these Electronic Support webcasts
  During the month of January, the Global WebSphere Community will offer a series of four electronic support webcasts. Check the web site for details on joining the webcasts:
  January 7 webcast – “It’s official – the IBM Support Portal is here!”
  January 14 webcast – “Quick guide to electronic support and a close look at the Service Request tool”
  January 21 webcast – “Discover IBM Support Assistant – ready to help when you need it”
  January 28 webcast – “IBM portfolio of troubleshooting tools: helping you solve problems faster”
  3. IBM WebSphere Application Server V7.0 Web Services Guide
  This IBM Redbooks publication describes how to implement Web services in IBM WebSphere Application Server V7. It starts by describing the concepts of the major building blocks on which Web services rely and leading practices for Web services applications.
  http://www.redbooks.ibm.com/abstracts/SG247758.html
  4. Technical Exchange Webcasts
  Take full advantage of your product. Join us as technical experts share their knowledge and then answer your questions. Visit this site often to see upcoming topics.
  http://www.ibm.com/software/websphere/support/supp_tech.html
  5. Self-Assist Resources and Tools
  Find out how online software support tools and resources can save you time, keep you informed, provide training, and help streamline your support experience!
  http://www.ibm.com/software/websphere/support/d2w.html
  6. developerWorks WebSphere Application Server zone
  Access the developerWorks page for downloads, learning resources and more.
  http://www.ibm.com/developerworks/websphere/zones/was/

In the spotlightPlan

Education

Kind regards,
The WebSphere Application Server team.

现在的服务器性能越来越强，内存动辄4G、8G，而32位JDK下，单个java堆一般不超过1.7G。那多出来的内存怎么办？建垂直集群（Vertical clusters：垂直集群是指同一机器上部署多个服务器，充分利用硬件资源）可以，简单的部署多个appserver也行。但是应用如何处理？如果多个项目都需要用相同的context root，比如说/，那怎么办？

其实做过网站的朋友都知道，一台服务器上一般不可能只放一个网站，那如何访问到这些网站，有三种方法：

1. IP不同，一个网卡上绑定多个IP，不同的IP对应不同的网站。
2. 端口不同，不同的网站运行在不同的端口上。
3. 虚拟主机不同，通过不同的虚拟主机名（一般都是域名）来访问。

那对于webshpere或者weblogic，很明显可以实行的是上述第三种方案。部署应用时会让我们选择部署到哪台虚拟主机，默认的都为default host，所以我们只要新建一个虚拟主机，名称一般为域名。那么就能实现通过一级域名直接访问应用。即使一台app server上部署了多个应用。

这种设置对于提供互联网服务的应用尤其有效，因为大家本来就是通过域名来访问的。而且即使只有一个应用，设置非默认的虚拟主机名可以起到只能通过域名来访问，而IP地址访问则会得到应用服务找到的错。虽说提高的安全性不多，但能满足年底全市各部门关于“只能通过域名访问，而IP无法访问”的要求。

至于内网用户，可以在内部dns上配置域名解析，或者编写hosts文件，达到同样效果。

更新：对于webshpere，我测试下来即使不同的虚拟主机，相同的上下文根也无法同时启动。在日志里会看到已经有重复的Context root了，这样的话只能配置apache使用它的虚拟主机解决

临近年末，各种考评将至，于是各单位信息中心开始“操心”数据安全，加之近期电信、移动严厉打击黄色信息，各领导也害怕黄色信息附带的病毒、木马危害数据安全，所以分外重视数据的备份。重要生产环境的数据当然早就做过全面细致的备份工作，但是一些不怎么重要的服务器，托管在机房的单独web服务器，采用Veritas等未免成本太高，所以这里介绍Acronis的备份产品。它们的产品线也很丰富，从单机到多台服务器应有尽有，价格应该可以为一般企业接受。

备份软件介绍

1．1概要：

Acronis True Image Echo Server for Windows

Acronis® True Image Echo Server for Windows可以在物理和虚拟环境中进行灾难恢复和系统迁移，为中小企业及远程办公室/分公司提供更大的灵活性和价值。

1.2 特点

• 不中断服务器运行的即时服务器磁盘备份
• 即时纯粹空机服务器还原
• 还原单个文件或文件夹
• 备份和升级服务器驱动器
• 自动排程服务器磁碟影像
• 建立增加服务器磁盘备份影像
• 嵌入式磁盘备份影像核查
• 磁盘备份影像确认在服务器恢复之前New!
• 文件系统确认在服务器恢复之后 New!
• 查看服务器磁盘备份日志 New!
• 电子邮件或弹开通知 New!
• 命令行服务器磁盘备份管理控制台 New!
• 支持窗口动态容量
• 支持 FAT16/32, NTFS, Linux Ext2, Ext3, ReiserFS, XFS, JFS New!
• 支持 SAN, NAS, RAID, 磁带驱动器, CD/DVD, 网络驱动器与其它备份储存
• 自动化的驱动精灵操作

其中不中断服务器运行的即时服务器磁盘备份、即时纯粹空机服务器还原、建立增加服务器磁盘备份影像、支持 SAN, NAS, RAID, 磁带驱动器, CD/DVD, 网络驱动器与其它备份储存这四个特点能满足目前项目服务器备份的要求。

2 备份方案介绍

结合备份的要求和Acronis True Image Echo Server for Windows软件的特点，制定了如下的备份方案：

l 在每台需要备份的服务器上安装Acronis True Image Echo Server for Windows

l 在服务器中划分10G的空间作为Acronis Secure Zone（划分大小根据你的数据量定），存放备份内容，这10G空间将变成隐藏空间，无法访问。以后备份的内容都在这10G空间中，当空间不足时老的备份内容会被覆盖。

l 制定每月一次全备份，每周一次增量备份的备份计划。

l 激活Acronis Startup Recovery，方便系统出故障后的备份还原。

l 备份一份最初的内容到DVD光盘，同时制作一张可引导备份光盘，以防万一。

3 操作过程

3.1 安装软件

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转载自 互联网的那点事

原文链接 http://www.alibuybuy.com/12098.html

如果你正在读这篇文章，那么很可能你花费了很多时间在网上。然而，考虑到互联网在我们日常生活中的影响，又有多少人了解互联网是如何起家的呢？下面是互联网的一个简史，包括重要的日期、人物、项目、网站以及其它可以让你至少明白我们现在称作互联网的到底是什么或者是从那里来的。

由于互联网完整的历史需要几本书来写，这篇文章只是让你熟悉在1969－2009年期间互联网的里程碑和给互联网带来变革和进步的事件。

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