2009年6月16日星期二

Download Junkies, Update Your System With RadarSync

Download Junkies, Update Your System With RadarSync

May. 29th, 2009 By Tim Watson

So, your Start Menu is a mile long, your Add/Remove Programs control panel takes a week to load, and your spouse is getting more annoyed with each successive "new thing" that pops up in the System Tray. Admit it. You're a download junkie. I know that I am, and that I like to keep everything up to date as much as possible. True geeks stay on the bleeding edge. That's where this new tool, RadarSync, comes in.


First, RadarSync scans your Windows system for programs which may need updating. It did not take long, even on a large, installation-heavy system like mine. I was pleasantly surprised by the number of programs the scanner recognized, including system drivers.  Once the scan results appeared, I had the opportunity to select which updates to download. Alternately, I had the option to save the list as a software "pack" using RadarSync's Packzoola service, which is free, for later use. Think of Packzoola packs as custom playlists for software which can be shared. You may view my example pack here.

With two clicks, you can download the installer files for all of your updates. RadarSync states that these updates come directly from the programs' official servers. The installers are stored in a folder under My Documents, and can be launched or deleted from RadarSync's interface.

radarSyncAllDownloadsSmall

You even will get a pop-up notice when the installer is available and will be prompted to create a System Restore point. By default, the installers are deleted after 30 days, which can be changed. For the security-conscious, RadarSync has a privacy policy.

radarSyncDownloadCompleteBubble

RadarSync makes for a quick and easy way to update Windows programs and system files. You may download it here. It's compatible with Windows XP and Vista on both 32 & 64-bit platforms.

发帖者 时间：

3 Wikis To Study Smarter Online

3 Wikis To Study Smarter Online

May. 30th, 2009 By Tina

WikiWiki is the Hawaiian word for quick. Being quick in every aspect - in using it and editing it - is a key factor in the success of Wikis.

Another factor is the hunger of people for information, knowledge and understanding. The faster, the better.

If you have ever been caught up in reading Wikipedia for hours on end, you'll know what I mean. One page leads to the next, it never ends. For students, wikis can be an incrediby useful and compared to textbooks, they are a quick source of support and information.

Here is a list of three Wikis that may help boost your online studying:

DiRT - Digital Research Tools Wiki

DiRT contains a comprehensive collection of tools and resources that can be used by students or scholars in their research.

Research Tools

The focus is on humanities and social sciences. However, containing articles on brainstorming, how to communicate with colleagues, how to prepare screencasts or network with other researchers, this wiki covers tools and guidelines that may prove useful not only for researchers, but also for people with other career backgrounds and especially for students who are still exploring fields. Check it out and let us know what you think.

I've also written about other tools you can use for research besides wikis.

Medpedia

As the name suggests, Medpedia is a recently-launched wiki concerned with medical topics. The goal is to share "the advancing knowledge about health, medicine and the body among medical professionals and the general public."

At this point, it contains hundreds of articles covering all types of human diseases and related medical background information. Nevertheless, the site states that you are not likely to find an article on the topic you are looking for. However, I did find everything I was looking for.

For med students, this Wiki can serve as a quick and easy way to research diseases and symptoms. Physicians and other experts are welcome to contribute to the site by editing pages or adding articles. Everyone else may suggest changes. All contributions will receive proper recognition.

If you're a medical student and you are searching for the best websites to for medical information, check out Jackson's article: The Best Reference Sites For Medical Students.

Textbook Revolution

textbookHere we have a resource specifically for students or those who wish to learn new tricks.

Textbook Revolution features free educational materials on a wide variety of topics such as biology, earth sciences or world history.

The site is run by students and was founded in response to overpriced textbooks whose publishers only have profits in mind, rather than educational value.

If you know of high quality free textbooks, make an account with Textbook Revolution and share the resource. If you have used any of the listed books, provide your feedback and review them.

Aside from wikis, I've also listed 10 Tools For Online Learning in a previous article, check it out. Looking for a textbook? Check out TextBook Torrents: Torrent Directory for Text Books.

As a student, what is your favorite Wiki and how did you discover it? Share them with us!

发帖者 时间：

7 Common Reasons Why Windows Can Get Unresponsive

7 Common Reasons Why Windows Can Get Unresponsive

Jun. 7th, 2009 By TanaG

A irresponsive system is a relatively common error you will encounter when using a PC. In many cases, you won't even get a message that your system is not responding because the computer has hung and it can't send you even that message. Very often, when your system is not responding, this means that neither the mouse, nor the keyboard are working and the only solution is to hit the Restart button.

When your system is not responding, usually CPU usage is at 100%, no matter if you do anything or not. On the other hand, it is not mandatory for this to happen, so if your CPU usage is not shown to be 100%, it is still possible that your system is not responding.

7 Reasons Why a System Is Not Responding

There are tons of reasons why a system can stop responding – it could be due to a hardware or a software conflict. Such errors don't happen only on PCs but on all kinds of hardware (if this is of any comfort to you) and the symptoms could vary – from a totally blocked machine - to a PC which is responding very, very slowly. Here are seven of the most common reasons why a system is not responding and what you can do to prevent them.

1. Hardware incompatibilities

This is one of the most frequent reasons why a system stops responding. The culprit could be anything – from a mouse/keyboard, to a CD drive, to a USB device. In some cases, you might even experience a Blue Screen of Death (BSOD), which is one more symptom of hardware incompatibilities. Remove the suspect and replace it with a functioning device and see if this helps.

bsod
A Blue Screen of Death is one of the most common symptoms when a system becomes irresponsive

2. Driver issues

Even if the hardware itself is not a problem, the drivers that manage it could be. If you have recently installed a new driver, this is the first suspect to check. Uninstall the driver and see if this helps. Don't worry, there are easy ways to remove old and faulty drivers from Windows.

3.Messed up Windows Registry

Windows and its Registry are very complex creatures and even minor messes with them could not only make a system not responding error but could even make a computer totally useless. That is why it is a good idea to clean your Windows and the Registry from time to time, even if there are no visible problems. One great way to do it is with the help of nCleaner.

4. Malware of all kinds

Spyware, adware, trojans and the other pests you get for free from the Internet, are also a common reasons why a system is not responding. Just run a good anti-malware program and that's it. Here are some great free online malware and virus scanners you might want to check.

5. Antivirus programs

As strange as it might sound, anti-virus programs can hang a computer. If you have more than one anti-virus program, conflicts between them are pretty common but even if you have only one anti-virus program, still there are many ways in which it can mess with the Registry, or with the applications on your computer, thus causing it to crash. Try to see which of the antivirus program is the problem and uninstall it. For antivirus recommendations, take a look at our poll for the best free Antivirus applications.

6. Bugs in applications

Poorly-written system tools and applications can cause a lot of trouble but it is not only system applications that can crash a computer. Browsers, such as Firefox or Internet Explorer can frequently hang when a poorly-written script is executed. If you are lucky to know which application in particular makes your system irresponsive, uninstall it (or in the case of a browser – disable the faulty plugin) and pray that this fixes the situation.

7. User intervention

Tweaks are great and very often they are safe to do (if you take the necessary precautions, of course) but as a matter of fact, tweaks that went bad are also a common reason for why a system is not responding. That's why you need to be very cautious when you tweak your computer. And above all – always make a backup, a system image and/or a restore point before you start tweaking, so that if the tweak goes unplanned, you still have a lifeline.

The above reasons and their suggested workarounds are just some of the most common causes as to why a system is not responding. When your system is not responding, try these solutions and if they solve your problem – be very, very happy about it!

Feeling geeky? Check out these articles to make your computer run faster and troubleshoot problems:

发帖者 时间：

2009年6月15日星期一

DRBD

DRBD

From Wikipedia, the free encyclopedia

Jump to: navigation, search
DRBD
Original author(s) Philipp Reisner, Lars Ellenberg
Developer(s) LINBIT (http://www.linbit.com)
Stable release 8.3.0 / December 18, 2008
Written in C
Operating system Linux
Development status Production
Type Distributed storage system
License GNU General Public License v2
Website http://www.drbd.org/
Free software portal
Overview of DRBD concept

DRBD (Distributed Replicated Block Device) is a distributed storage system for the Linux platform. It consists of a kernel module, several userspace management applications and some shell scripts and is normally used on high availability (HA) clusters. DRBD bears similarities to RAID 1, except that it runs over a network.

DRBD refers to both the software (kernel module and associated userspace tools), and also to specific logical block devices managed by the software. DRBD device and DRBD block device are also often used for the latter, although these are examples of RAS syndrome.

It is free software released under the terms of the GNU General Public License version 2.

Contents

[hide]

[edit] Mode of operation

DRBD layers logical block devices (conventionally named /dev/drbdX, where X is the device minor number) over existing local block devices on participating cluster nodes. Writes to the primary node are transferred to the lower-level block device and simultaneously propagated to the secondary node. The secondary node then transfers data to its corresponding lower-level block device. All read I/O is performed locally.

Should the primary node fail, a cluster management process promotes the secondary node to a primary state. This transition may require a subsequent verification of the integrity of the file system stacked on top of DRBD, by way of a filesystem check or a journal replay. When the failed ex-primary node returns, the system may (or may not) raise it to primary level again, after device data resynchronization. DRBD's synchronization algorithm is efficient in the sense that only those blocks that were changed during the outage must be resynchronized, rather than the device in its entirety.

DRBD is often deployed together with the Heartbeat cluster manager, although it does integrate with other cluster management frameworks. It integrates with virtualization solutions such as Xen, and may be used both below and on top of the Linux LVM stack.[1]

DRBD version 8, released in January 2007, introduced support for load-balancing configurations, allowing both nodes to access a particular DRBD in read/write mode with shared storage semantics.[2] Such a configuration requires the use of a distributed lock manager.

[edit] Advantages over shared cluster storage

Conventional computer cluster systems typically use some sort of shared storage for data being used by cluster resources. This approach has a number of disadvantages, which DRBD may help offset:

  • Shared storage resources usually introduce a single point of failure in the cluster setup — while each of the cluster nodes may fail without causing service interruption, storage failure almost inevitably causes service downtime. In DRBD, no such issues exist as the cluster resource data is replicated rather than shared.
  • Shared storage resources are particularly sensitive to split brain situations, where both cluster nodes are still alive, but lose all network connectivity between them. In such a scenario, each cluster node will assume that it is the only surviving node in the cluster, and take over all cluster resources. This may lead to potentially disastrous results when both nodes, for example, mount and write to file systems concurrently. Cluster administrators must thus carefully implement node fencing policies to avoid this. DRBD substantially mitigates this problem by keeping two replicated sets of data instead of one shared set.
  • Shared storage resources must typically be addressed over a SAN or NAS, which creates some overhead in read I/O. In DRBD that overhead is greatly reduced as all read operations are carried out locally.

[edit] Applications

Operating within the Linux kernel's block layer, DRBD is essentially workload agnostic. A DRBD can be used as the basis of

DRBD-based clusters are often employed for adding synchronous replication and high availability to file servers, relational databases (such as MySQL), and many other workloads.

[edit] Possible inclusion in Linux kernel

DRBD's authors submitted the software to the Linux kernel community in July 2007, for possible future inclusion of DRBD into the "vanilla" Linux kernel.[3] As of April 2009, the community's review is ongoing.

[edit] References

  1. ^ Haas, Florian; Reisner, Philipp; Ellenberg, Lars, The DRBD User's Guide, http://www.drbd.org/users-guide/, retrieved on 2008-03-31 
  2. ^ Reisner, Philipp (2005-10-11). "DRBD v8 - Replicated Storage with Shared Disk Semantics". Proceedings of the 12th International Linux System Technology Conference. 
  3. ^ Ellenberg, Lars (2007-07-21). "DRBD wants to go mainline". linux-kernel mailing list. http://lkml.org/lkml/2007/7/21/255. Retrieved on 2007-08-03. 

[edit] External links

Sister project Wikimedia Commons has media related to: DRBD
发帖者 时间：

How to use dstat to monitor your Linux/UNIX server

How to use dstat to monitor your Linux/UNIX server如何使用dstat监控您的Linux / UNIX服务器

by Sukrit Dhandhania on November 13, 2008 由 Sukrit Dhandhania 关于 2008年十一月十三日

Linux操作系统

If you have a Linux server running at your office or at a data center for which you are responsible, you want to maintain an uptime of as close to a hundred percent.如果您有一个Linux服务器运行在您的办公室或在数据中心，您有责任，要保持正常运行时间接近百分之百。 In such a case you want to make sure you keep an eye on how the system is running.在这种情况下要确保您留意系统如何运行。 To be precise you want to monitor all the system resources that contribute to the system running fine which then results in a high uptime.要准确要监控所有的系统资源，有助于该系统运行良好的结果，然后在一个高的正常运行时间。 Memory, CPU, disk usage… are some of the things you want to observe.内存，处理器，磁盘使用...有一些事情要观察。 We would usually use a combination of the tools that come with a Linux or UNIX installation, such as "free", "top", "vmstat"… I'll introduce you to a tool that gives you just about all the info that the other tools combined give you, all under one roof - Dstat.我们通常会结合使用的工具，来了一个Linux或UNIX安装，如"自由" ， "顶级" ， " vmstat " ...我会向您介绍一个工具，让您刚才所有的信息说，其他工具结合起来给你，所有的同一个屋檐下-D stat。 The developer of this command line tool, Dag Wieers, calls it "a versatile replacement for vmstat, iostat, netstat and ifstat".开发商的这一命令行工具，达格哈马Wieers ，将其称为"多面手更换vmstat ， iostat ， netstat和ifstat " 。 He adds that "Dstat overcomes some of their limitations and adds some extra features…" To me Dstat is the mother of all command line system monitoring tools.他补充说， " Dstat克服了它们的某些限制，并增加了一些额外的功能... "对我来说Dstat是母亲的所有命令行系统监测工具。 It's simple to install, easy to use, can be tweaked with ease, and it generates reports that you can plot as a graph to impress your boss.它安装简单，易于使用，可以轻松地调整，并生成报告，可以作为一个阴谋图你的老板留下深刻的印象。

Installing Dstat安装Dstat

Start by downloading the Dstat installer.开始下载Dstat安装。 Point your web browser to the Dstat project's homepage -点你的网络浏览器的Dstat项目的主页- http://dag.wieers.com/home-made/dstat/ . 。 Scroll down to the section of the page where the downloads are listed.向下滚动到部分的网页下载列。 Pick the flavor of Linux on which you want to install the application and click on the download link.挑选风味的Linux要安装的应用，并点击下载链接。 Now download the latest version of Dstat for the version of the Linux distribution you are running.现在下载最新版本的Dstat的版本的Linux分布您正在运行。 I'll show you how to do it for a Red Hat Enterprise Linux version 4 machine:我会告诉您如何做到这一点的红帽企业Linux第4版机：

# wget http://dag.wieers.com/rpm/packages/dstat/dstat-0.6.6-1.el4.rf.noarch.rpm ＃ wget http://dag.wieers.com/rpm/packages/dstat/dstat-0.6.6-1.el4.rf.noarch.rpm

Now install Dstat:现在安装Dstat ：

# rpm -Uvh dstat-0.6.6-1.el4.rf.noarch.rpm ＃更高Uvh dstat - 0.6.6 - 1.el4.rf.noarch.rpm

If the installation went though without errors, that's it, you have Dstat installed and ready for use.如果安装了但没有错误，就是这样，你Dstat安装好且可以使用。 If there were some dependencies that came up during the installation just install the required packages and try again.如果有一些相依来到了在安装过程中只安装所需的软件包，然后再试一次。 I don't think that Dstat has too many dependencies, so you should not face any problems.我不认为Dstat有太多依赖，所以你不应该遇到任何问题。

Using Dstat使用Dstat

With Dstat installed on your system you should be good to go.随着Dstat安装在您的系统你要善于去。 Begin by launching the command from a terminal:首先启动的命令从一个终端：

# dstat ＃ dstat

The output would be something like the following.输出将类似于以下。 Hit the key combination of ctrl+c to exit.命中关键结合按Ctrl + C退出。

# dstat ＃ dstat
―-total-cpu-usage―- -disk/total -net/total- ―paging� ―system� -总的C PU使用率- -d isk/total-n et/total-，传呼，系统
usr sys idl wai hiq siq|_read write|_recv _send|__in_ _out_|_int_ _csw_系统语言遭围hiq siq | _read写| _recv _send | __in_ _out_ | _int_ _csw_
7 1 91 1 0 0| 0 0 | 0 0 | 0 0 | 0 0 7条1 91 1 0 0 | 0 0 | 0 0 | 0 0 | 0 0
1 0 99 0 0 0| 0 0 | 0 0 | 0 0 |1051 1945 1 0 99 0 0 0 | 0 0 | 0 0 | 0 0 | 1051年1945年
0 0 100 0 0 0| 0 12k|2269B 11.2k| 0 0 |1031 1923 0 0 100 0 0 0 | 0 12,000 | 2269B 11.2k | 0 0 | 1031年1923年
1 0 99 0 0 0| 0 40k| 0 0 | 0 0 |1078 2235 1 0 99 0 0 0 | 0 40K的| 0 0 | 0 0 | 1078 2235
0 0 100 0 0 0| 0 16k|6027B 21.5k| 0 0 |1008 2219 0 0 100 0 0 0 | 0最大16K | 6027B 21.5k | 0 0 | 1008年2219年

There are a number of options available for Dstat.有一些可供选择Dstat 。 As I mentioned earlier Dstat is quite easy to tweak.正如我前面提到Dstat很容易调整。 So if you want to limit the data reading to the CPU, disk, and network, run the following command:所以，如果你想限制数据读的CPU ，硬盘和网络，运行下面的命令：

# dstat -CDN ＃ dstat -原价
-disk/total -net/total- ―paging� ―system� -disk/total -net/total- ，传呼，系统
_read write|_recv _send|__in_ _out_|_int_ _csw_ _read写| _recv _send | __in_ _out_ | _int_ _csw_
0 0 | 0 0 | 0 0 | 0 0 0 0 | 0 0 | 0 0 | 0 0
0 12k|2295B 9603B| 0 0 |1053 1957 0 12,000 | 2295B 9603B | 0 0 | 1053年1957年
0 0 | 594B 0 | 0 0 |1002 1893 0 0 | 594B 0 | 0 0 | 1002年1893年
0 960k| 292B 3346B| 0 0 |1072 2012 0 960k | 292B 3346B | 0 0 | 1072年2012年
0 4096B| 64B 0 | 0 0 |1031 1939 0 4096B |个64 0 | 0 0 | 1031年1939年

You can find more options in the application's help document which you can access by entering the following:您可以找到更多的选择的应用程序的帮助文件，您可以通过输入以下内容：

# dstat -h ＃ dstat小时

Play with the options a little so you get comfortable with them.播放的选项一点，让您获得舒适与他们。 The default interval between data reads is two seconds.预设的间隔读取数据是2秒。 You can change that interval if you need to.你可以改变这一区间如果您需要。 To increase the interval to ten seconds enter the following:为了增加间隔十秒输入以下内容：

# dstat 10 ＃ dstat 10个

Another useful feature is to get aggregated updates for each entry.另一个有用的功能就是要更新汇总每个条目。 So you can have Dstat give you an update every ten seconds in a new line, but as the data changes your line itself gets updated every second.所以，你可以有Dstat给你一个更新每10秒一个新行，但作为数据变化的路线本身更新一次获得第二。

You might optionally want Dstat to give you five updates with a frequency of three seconds.你可能会选择想要Dstat给你5个更新的频率3秒。 Here's how you would go about doing that:以下是如何你会去这样做：

# dstat 3 5 ＃ dstat 3月5日
―-total-cpu-usage―- -disk/total -net/total- ―paging� ―system� -总的C PU使用率- -d isk/total-n et/total-，传呼，系统
usr sys idl wai hiq siq|_read write|_recv _send|__in_ _out_|_int_ _csw_系统语言遭围hiq siq | _read写| _recv _send | __in_ _out_ | _int_ _csw_
3 1 95 2 0 0| 0 0 | 0 0 | 0 0 | 0 0 1月3日95 2 0 0 | 0 0 | 0 0 | 0 0 | 0 0
2 11 87 1 0 0| 0 180k|2581B 3239B| 0 0 |1136 697 2月11日87 1 0 0 | 0 180,000 | 2581B 3239B | 0 0 | 1136 697
7 8 85 0 0 0| 0 0 | 115k 106k| 0 0 |1603 3985 7月8日85 0 0 0 | 0 0 | 115k 106k | 0 0 | 1603年3985
2 1 98 0 0 0| 0 0 |77.5k 170k| 0 0 |1744 3856 2月1日98 0 0 0 | 0 0 | 77.5k 82 | 0 0 | 1744 3856
1 0 100 0 0 0| 0 0 |3451B 9993B| 0 0 |1045 149 1 0 100 0 0 0 | 0 0 | 3451B 9993B | 0 0 | 10时45分149
2 1 94 4 0 0| 0 276k|20.4k 31.1k| 0 0 |1219 804 2月1日94 4 0 0 | 0 276k | 20.4k 31.1k | 0 0 | 1219 804

The feature that I find most useful is the output.这项功能，我认为最有用的是输出。 Dstat allows you to have the output of a session written into a comma separated file which can later be imported into a spreadsheet application such as Microsoft Excel and the data can be plotted into a graph. Dstat可以让你的输出写入会议逗号分隔文件，该文件可以在以后导入到电子表格应用程序，如Microsoft Excel中的数据可以绘制成图表。 Here is how it can be used.下面是它如何被使用。

# dstat �output /tmp/dstat_data.csv -CDN ＃ dstat输出/ tmp的/ dstat_data.csv -原价

Let the above command run while you run your applications or do your testing on this machine.让执行上述命令时，运行您的应用程序或做您的测试本机上。 Hit the key combination of ctrl+c when you are done.命中关键结合按Ctrl + C当你做。 Open the file dstat_data.csv with a spreadsheet application such as Microsoft Excel or Open Office.打开文件dstat_data.csv与试算表应用程式如Microsoft Excel或开放式办公。 You can then select the columns you want plotted into a graph and let your spreadsheet application do the magic.然后，您可以选择您想要栏绘制成图表，让您的电子表格应用程序做的魔力。

Get a Report by Mail收到邮件的报告

There may be cases wherein you want to observe how your server is performing over a period of time.有可能出现这样的情况，其中你想观察一下您的服务器正在执行一段时间。 You can setup a background process in Linux that will give you a reading with a certain interval, generate a report, and mail out the file to you.您可以设置一个后台进程在Linux中，将让您阅读具有一定的间隔，产生了一份报告，并邮寄出的档案给你。 This can be especially useful during a stress-test.这可能是特别有用在应力测试。 Here's how you could do that.以下是你可以做到这一点。 The following script will run Dstat for three hours, reading the data every 30 seconds, and will mail out the report to me@myemailid.com.下面的脚本将运行Dstat了三个小时，阅读的数据，每30秒，并将邮件的报告me@myemailid.com 。

#!/bin/bash ＃ ！ /斌/庆祝
dstat �output /tmp/dstat_data_mail.csv -CDN 30 360 dstat输出/ tmp的/ dstat_data_mail.csv - 30原价360
mutt -a /tmp/dstat_data_mail.csv -s "Dstat Report for 3 hour run" me@myemailid.com < /dev/null傻子一个/ tmp的/ dstat_data_mail.csv比较" Dstat报告3小时运行" me@myemailid.com "的/ dev /无效

Save the above script in a file called dstat_script.sh on your server, give it executable permission and then run it as a background process:除上述脚本在一个名为dstat_script.sh在您的服务器上，给它可执行权限，然后运行它作为背景的过程：

# chmod +x dstat_script.sh ＃属性+ x的dstat_script.sh
# nohup ./dstat_script.sh & ＃ nohup 。 / dstat_script.sh ＆

Done.做完。 Yes, it's that simple.是啊，这么简单。 You will now be mailed this report after it's done running.现在，您将寄出这份报告后的工作运行。 You can optionally schedule this script as a daily cron job so that you can receive this data every day.您可以选择这个剧本的时间表作为日常作业，让您可以收到这个数据每天都在。

As you may already have realized Dstat is a wonderful tool when applied to performance monitoring and debugging.正如你可能已经意识到Dstat是一种非常棒的工具，当适用于执行情况的监测和调试。 The granularity, frequency, and nature of the data collected are completely up to you.粒度，频率和性质，所收集的数据是完全取决于您。 Dstat empowers you to know what is going on on your server. Dstat赋予你知道是怎么回事在您的服务器上。 Used wisely this power can result in a lot less sleepless nights for you.明智地使用这种权力会导致少很多不眠之夜你。

Related Posts: 相关文章：
  • How to monitor your Mac laptop's battery health如何监视你的Mac笔记本电脑的电池健康
  • How to share a keyboard and mouse with multiple computers如何共用一个键盘和鼠标与多台计算机
  • How to monitor your Internet bandwidth usage in OS X如何监视你的网络带宽使用的OS X操作系统
  • 5 More OS X Dashbooard Widgets for Bloggers 5更多OS X的Dashbooard构件的博客
  • How to monitor your Internet bandwidth usage in OS X, redux如何监视你的网络带宽使用的OS X中， redux
    • 发帖者 时间：

    2009年6月14日星期日

    RHCE十周年：38，000个红帽认证工程师遍布全球

    RHCE十周年：38，000个红帽认证工程师遍布全球

    [日期：2009-06-13] 来源：eNet硅谷动力  作者：Linux编辑

    　 　6月2日，红帽RHCE十周年庆典在北京交通大学科学学堂正式举办，庆典内容包括现场Linux技术较量及主题演讲两大部分。红帽大中华区总裁胡柏林、 红帽大中华区培训和服务经理黄健耀，来自世界500强的外资企业经理人及诸多RHCE获得者出席了此次活动。在庆典现场，同学们及远道而来的开源爱好者齐 聚一堂，与红帽专家、职场精英共同交流Linux前沿知识，探讨经济危机形式下Linux人才的机遇。

    RHCE十周年：38,000个红帽认证工程师遍布全球


    　　在RHCE十周年庆典活动沙龙现场，Linux爱好者进行了激烈的Linux技术较量，随后红帽Linux技术精英为现场的同学详解参赛题。参 加技术较量的同学均表示，红帽认证工程师（RHCE）实战性较强，能够较好地证明个人Linux实际应用水平，并期待早日通过RHCE认证，在职场道路上 快人一步。

    　　在主题演讲会场，胡柏林发表了主题为“开源发展前景”的演讲。胡柏林表示，在经济危机的形式下，美国政府以及各行业均将大幅度采用开源软件以节 省成本。2009年3月17日，美国国防部防务信息系统局宣布和开源软件研究会（OSSI）签署联合开发和研究协议（CRADA）。红帽作为开源厂商中的 佼佼者自然获得了不俗市场表现，并在“未来十年影响信息产业方向的公司”评选中位列第八。2009年2月18日，DLT与US DISA签署了18，000，000美金一揽子Redhat Enterprise Linux订阅和服务采购协议，协议有效期长达五年。2009年3月20日，CarahSoft与USESI签署协议，为ESI提供RHEL、 JBoss、MySQL技术服务及一年期订阅服务。

    　　黄健耀分享了主题为“中国Linux市场走向与人才需求分析”的演讲。黄健耀介绍，在IT培训市场份额方面，红帽一直占据着举足轻重的地位，并 呈快速上升趋势。调查表明，2007年红帽是IT培训第一阵营的三巨头之一，2009年红帽已经成为领导区域的唯一。RHCE一直以来是市场需求最为迫切 的IT认证，原因是在团队技能和厂商支持这两大关键要素方面，红帽被认为尤为出色。

    　　随着Linux在经济危机形式下的表现优异发展迅猛，Linux认证也随着大热。调查数据表明，目前Linux认证所占比例高达38.5%，与微软认证不相上下。在Linux认证中，红帽认证占据比例高达61.2%，远超过LPIC、TLCE、Novell SuSE的 市场份额。与2008年相比，2009年Linux认证市场份额增长显著，RHCT认证由71.7%增长到72.2%，RHCE认证由68.4%增长到 70.6%，RHCA认证由46.7%增长到67.5%。在“2008最热门10大IT国际认证”排行中，RHCE认证遥遥领先。中国的IT认证市场需求 曾远远落后于国际水平，但市场潜力巨大。2007年中国在亚太区IT认证排名位居第四，2009年5月已上升到第三位。红帽表示看好Linux认证在中国 的市场机遇。

    　　现场还有来自世界500强的职业经理人与大家畅谈“知识经济对企业的影响”，以及RHCE明星分享从菜鸟到Linux高手的进阶培训。该 RHCE明星表示将全力挑战从RHCT到RHCE到RHCA到RHCSS的系列认证。凭借优异表现，其获得2个月的红帽内部培训，随之赢得红帽实习机会， 最终凭借出色表现成为红帽大家族中的一员。

    　　RHCE认证启动于1999年，是以考动手能力为主的最大的Linux认证项目之一。目前，全球已有近38,000个红帽认证工程师们帮助他们的公司作成功的 Linux部署和迁移。未来，红帽系列认证将帮助全球范围内及中国的开源爱好者们在开源领域内获得非凡成功。

    发帖者 时间：

    tomcat下catalina.out日志文件分割

    tomcat下catalina.out日志文件分割

    使用log4j成功使catalina.out文件实现分割。

    在tomcat根目录下建立common/classes/log4j.properties，内容如下：
    ############################################################################
    log4j.rootLogger=INFO, R
    log4j.appender.R=org.apache.log4j.RollingFileAppender
    log4j.appender.R.File=${catalina.home}/logs/tomcat.newlog  #设定日志文件名
    log4j.appender.R.MaxFileSize=100KB   #设定文件到100kb即分割
    log4j.appender.R.MaxBackupIndex=10   #设定日志文件保留的序号数
    log4j.appender.R.layout=org.apache.log4j.PatternLayout
    log4j.appender.R.layout.ConversionPattern=%p %t %c - %m%n
    ############################################################################

    在tomcat根目录下的common/lib下加入log4j.jar和commons-logging.jar

    重新启动tomcat即可。

    参考：
    http://tomcat.apache.org/tomcat-5.5-doc/logging.html
    发帖者 时间：

    Logging in Tomcat 6.0

    Apache Tomcat 6.0

    Logging in Tomcat

    Important note

    By default, only java.util.logging is available for the core Tomcat, as Tomcat uses a package renamed logging implementation which is hardcoded for that logger. Usage of alternate loggers is available after building or downloading the extra components (see the extras components documentation), which includes a full commons-logging implementation.

    Introduction

    Tomcat 6.0 uses Commons Logging throughout its internal code allowing the developer to choose a logging configuration that suits their needs, e.g java.util.logging or Log4J. Commons Logging provides Tomcat the ability to log hierarchially across various log levels without needing to rely on a particular logging implementation.

    An important consequence for Tomcat 6.0 is that the <Logger> element found in previous versions to create a localhost_log is no longer a valid nested element of <Context>. Instead, the default Tomcat configuration will use java.util.logging. If the developer wishes to collect detailed internal Tomcat logging (i.e what is happening within the Tomcat engine), then they should configure a logging system such as java.util.logging or log4j as detailed next.

    log4j

    Tomcat 6.0 has done away with localhost_log which you may be familiar with as the runtime exception/stack trace log. These types of error are usually thrown by uncaught exceptions, but are still valuable to the developer. They can now be found in the stdout log.

    If you need to setup cross-context detailed logging from within Tomcat's code, then you can use a simple log4j configuration. Note that this logging can be very verbose depending on the log level you chose to use. Note also that a log4j logging configuration is not going to produce stack trace type logging: those stack traces are output to stdout as discussed above.

    Follow the following steps to setup a file named tomcat.log that has internal Tomcat logging output to it:

    1. Create a file called log4j.properties with the following content and save it into $CATALINA_HOME/lib. 
                  log4j.rootLogger=debug, R 
                   log4j.appender.R=org.apache.log4j.RollingFileAppender 
                  log4j.appender.R.File=${catalina.home}/logs/tomcat.log 
                  log4j.appender.R.MaxFileSize=10MB 
                  log4j.appender.R.MaxBackupIndex=10 
                   log4j.appender.R.layout=org.apache.log4j.PatternLayout 
                  log4j.appender.R.layout.ConversionPattern=%p %t %c - %m%n 
                  log4j.logger.org.apache.catalina=DEBUG, R
    2. Download Log4J (v1.2 or later) and place the log4j jar in $CATALINA_HOME/lib.
    3. Build or download the additional logging components. See the extras components documentation for details.
    4. Replace $CATALINA_HOME/bin/tomcat-juli.jar with output/extras/tomcat-juli.jar.
    5. Place output/extras/tomcat-juli-adapters.jar in $CATALINA_HOME/lib.
    6. Start Tomcat

    This log4j configuration sets up a file called tomcat.log in your Tomcat logs folder with a maximum file size of 10MB and up to 10 backups. DEBUG level is specified which will result in the most verbose output from Tomcat.

    You can (and should) be more picky about which packages to include in the logging. Tomcat 6 defines loggers by Engine and Host names. For example, for a default Catalina localhost log, add this to the end of the log4j.properties above. Note that there are known issues with using this naming convention (with square brackets) in log4j XML based configuration files, so we recommend you use a properties file as described until a future version of log4j allows this convention.

    • log4j.logger.org.apache.catalina.core.ContainerBase.[Catalina].[localhost]=DEBUG, R
    • log4j.logger.org.apache.catalina.core=DEBUG, R
    • log4j.logger.org.apache.catalina.session=DEBUG, R
    Be warned a level of DEBUG will produce megabytes of logging and slow startup of Tomcat. This level should be used sparingly when debugging of internal Tomcat operations is required.

    Your web applications should certainly use their own log4j configuration. This is valid with the above configuration. You would place a similar log4j.properties file in your web application's WEB-INF/classes folder, and log4j1.2.8.jar into WEB-INF/lib. Then specify your package level logging. This is a basic setup of log4j which does *not* require Commons-Logging, and you should consult the log4j documentation for more options. This page is intended only as a bootstrapping guide.

    java.util.logging

    The default implemenatation of java.util.logging provided in the JDK is too limited to be useful. A limitation of JDK Logging appears to be the inability to have per-web application logging, as the configuration is per-VM. As a result, Tomcat will, in the default configuration, replace the default LogManager implementation with a container friendly implementation called JULI, which addresses these shortcomings. It supports the same configuration mechanisms as the standard JDK java.util.logging, using either a programmatic approach, or properties files. The main difference is that per-classloader properties files can be set (which enables easy redeployment friendly webapp configuration), and the properties files support slightly extended constructs which allows more freedom for defining handlers and assigning them to loggers.

    JULI is enabled by default in Tomcat 6.0, and supports per classloader configuration, in addition to the regular global java.util.logging configuration. This means that logging can be configured at the following layers:

    • In the JDK's logging.properties file. Check your JAVA_HOME environment setting to see which JDK Tomcat is using. The file will be in $JAVA_HOME/jre/lib. Alternately, it can also use a global configuration file located elsewhere by using the system property java.util.logging.config.file, or programmatic configuration using java.util.logging.config.class.
    • In each classloader using a logging.properties file. This means that it is possible to have a configuration for the Tomcat core, as well as separate configurations for each webapps which will have the same lifecycle as the webapps.

    The default logging.properties specifies a ConsoleHandler for routing logging to stdout and also a FileHandler. A handler's log level threshold can be set using SEVERE, WARNING, INFO, CONFIG, FINE, FINER, FINEST or ALL. The logging.properties shipped with JDK is set to INFO. You can also target specific packages to collect logging from and specify a level. Here is how you would set debugging from Tomcat. You would need to ensure the ConsoleHandler's level is also set to collect this threshold, so FINEST or ALL should be set. Please refer to Sun's java.util.logging documentation for the complete details. 

    org.apache.catalina.level=FINEST

    The configuration used by JULI is extremely similar, but uses a few extensions to allow better flexibility in assigning loggers. The main differences are:

    • A prefix may be added to handler names, so that multiple handlers of a single class may be instantiated. A prefix is a String which starts with a digit, and ends with '.'. For example, 22foobar. is a valid prefix.
    • As in Java 5.0, loggers can define a list of handlers using the loggerName.handlers property.
    • By default, loggers will not delegate to their parent if they have associated handlers. This may be changed per logger using the loggerName.useParentHandlers property, which accepts a boolean value.
    • The root logger can define its set of handlers using a .handlers property.
    • System property replacement for property values which start with ${systemPropertyName}.

    Example logging.properties file to be placed in $CATALINA_BASE/conf: 

    handlers = 1catalina.org.apache.juli.FileHandler, 2localhost.org.apache.juli.FileHandler, \
                3manager.org.apache.juli.FileHandler, 4admin.org.apache.juli.FileHandler, \
               java.util.logging.ConsoleHandler

    .handlers = 1catalina.org.apache.juli.FileHandler, java.util.logging.ConsoleHandler
     
    ############################################################
    # Handler specific properties.
    # Describes specific configuration info for Handlers.
    ############################################################
     
    1catalina.org.apache.juli.FileHandler.level = FINE
    1catalina.org.apache.juli.FileHandler.directory = ${catalina.base}/logs
    1catalina.org.apache.juli.FileHandler.prefix = catalina.

    2localhost.org.apache.juli.FileHandler.level = FINE
     2localhost.org.apache.juli.FileHandler.directory = ${catalina.base}/logs
    2localhost.org.apache.juli.FileHandler.prefix = localhost.

    3manager.org.apache.juli.FileHandler.level = FINE
    3manager.org.apache.juli.FileHandler.directory = ${catalina.base}/logs
     3manager.org.apache.juli.FileHandler.prefix = manager.

    4admin.org.apache.juli.FileHandler.level = FINE
    4admin.org.apache.juli.FileHandler.directory = ${catalina.base}/logs
    4admin.org.apache.juli.FileHandler.prefix = admin.
     
    java.util.logging.ConsoleHandler.level = FINE
    java.util.logging.ConsoleHandler.formatter = java.util.logging.SimpleFormatter


    ############################################################
    # Facility specific properties.
     # Provides extra control for each logger.
    ############################################################

    org.apache.catalina.core.ContainerBase.[Catalina].[localhost].level = INFO
    org.apache.catalina.core.ContainerBase.[Catalina].[localhost].handlers = \
        2localhost.org.apache.juli.FileHandler

    org.apache.catalina.core.ContainerBase.[Catalina].[localhost].[/manager].level = INFO
    org.apache.catalina.core.ContainerBase.[Catalina].[localhost].[/manager].handlers = \
        3manager.org.apache.juli.FileHandler

    org.apache.catalina.core.ContainerBase.[Catalina].[localhost].[/admin].level = INFO
    org.apache.catalina.core.ContainerBase.[Catalina].[localhost].[/admin].handlers = \
        4admin.org.apache.juli.FileHandler

    # For example, set the com.xyz.foo logger to only log SEVERE
    # messages:
    #org.apache.catalina.startup.ContextConfig.level = FINE
    #org.apache.catalina.startup.HostConfig.level = FINE
     #org.apache.catalina.session.ManagerBase.level = FINE

    Example logging.properties for the servlet-examples web application to be placed in WEB-INF/classes inside the web application: 

    handlers = org.apache.juli.FileHandler, java.util.logging.ConsoleHandler
     
    ############################################################
    # Handler specific properties.
    # Describes specific configuration info for Handlers.
    ############################################################
     
    org.apache.juli.FileHandler.level = FINE
    org.apache.juli.FileHandler.directory = ${catalina.base}/logs
    org.apache.juli.FileHandler.prefix = servlet-examples.

    java.util.logging.ConsoleHandler.level = FINE
     java.util.logging.ConsoleHandler.formatter = java.util.logging.SimpleFormatter
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