Tuesday, January 18, 2011

Appcmd ERROR: Cannot read configuration file due to insifficient permissions

Grant whatever access you need, but don't assume that access is automatic just because you're an admin.  It's an account or group, and permissions can be set just as with any other account or mgroup.

So adding my userid to the folder %systemroot%\system32\inetsrv\config to fix the issue

Monday, January 17, 2011

With Active Directory (AD), Sql server agent cannot start problem's solution.

After AD promotion, sql server agent  cannot start with error message:
"No mapping between account names and security IDs was done. [0x80070534]." .. or whatever..
For this case. you cannot to change the account used by the SQL Server services via SQL Server Configuration Manager since it is trying to resolve the SID of the old account to the name of the user, and can't do it.
To solve the problem, go to the Windows Services applet (services.msc) and use that to change the account used by the service. For the service to function properly the new account would have to be one that you know has enough privileges. Or just change it to any user that exists, and then go back to Configuration Manager (which will hopefully work now) and change it again, so that the privileges are set correctly.

Tuesday, January 11, 2011

二十个SEO概念

1. 搜索引擎营销 (SEM)
搜索引擎营销(SEM)英文全称为Search Engine Marketing,意指通过搜索引擎进行服务和产品的营销。搜索引擎营销又主要分为两种:搜索引擎优化(SEO)和付费点击(PPC,Pay-Per- Click)。搜索引擎优化(SEO)指通过优化网站和页面并让它们在搜索结果的页面中展示,而付费点击(PPC)指通过购买搜索引擎的点击将用户带到自 己的网站。(通常)这些点击来自搜索结果页面中的“赞助商链接”(译注:显然不适用于百度)。
2. 反向链接(Backlink)
反向链接(Backlink)又称为“回指链接”“入链”和“简易链接”,指从其他网站指向你的网站的一个超级链接。反向链接之所以对SEO异常重要,是因为它们直接影响一个网页的页面等级(PageRank),以及这个页面在搜索结果中的排名。
3. 页面等级(PageRank)
页面等级( PageRank) 是Goolgle用来评估一个页面相对于其他页面的重要性的一个算法规则。这个算法规则最基本的意思就是说,如果A页面有一个链接指向B页面,那就可以看 作是A页面对B页面的一种信任或推荐。所以,如果一个页面的反向链接越多,再根据这些链接的价值加权越高,那搜索引擎就会判断这样的页面更为重要,页面等 级(PageRank)也就越高。
4. 链接诱饵(饵链)(Linkbait)
链接诱饵(Linkbait),顾名思义这是一个网站或一个博客上为了尽可能多地吸引反向链接(目的是提高网站的PR值)而存在的一段内容。通常,这些做 为诱饵的内容为文字内容,但也可以是一段视频、一张图片、一个测验或其他的热门的内容。最经典的诱饵内容的例子是“十大(Top 10)”,因为这样的内容在一些社交网站很容易流行起来成为热门话题(译注:这个话题貌似已经臭街了)。
5. 互链车间或互链作坊(Link farm)
互链工厂或互链作坊(Link farm)是指很多网站(通常数量很大)为了提高组成一个类似车间或作坊式的团体,通过彼此的互相链接来提高团体每一个的网站的页面评级的手段。早期,这种方法很有用,但现在已经成为一种不耻的作弊手段(并可能会收到惩罚)。
6. 锚文本(Anchor text)
锚文本(Anchor text)在反向链接中是指一个页面中可点击的文本,而其中的关键词对搜索引擎优化(SEO)有很大的帮助,因为Google会将这些关键词和你的内容关联起来。
7. 链接属性-NoFollow
Nofollow是网站管理员使用的一个链接属性,其目的是告诉搜索引擎他们并不是为该链接所指向的网站投票。这种链接也可能是网站用户自己创造的内容 (比如博客评论中的链接),或者是一个付费交易的链接(比如广告或赞助商的链接)。当Google识别到这些反向链接的NoFollow属性后,基本就不 会在页面评级和搜索结果排名的算法中将这些链接的贡献计算在内了。
8. 链接修饰(Link Sculpting)
链接修饰(Link Sculpting)是指网站管理员对网站上其他网站的反向链接进行属性设置。比如,管理员给链接添加Nofollow属性,这可以让管理员决定利用自己 的网站为具体某个网站提高页面评级,或者不帮助具体某个网站提高网页评级。不过,现在这种做法的作用已经微乎其微,因为Google已经决定要用自己的算 法来决定怎么处理链接的Nofollow属性。
9. 页面标题(Title Tag)
页面标题(Title Tag),顾名思义是指一个页面的标题中,这也是Google搜索算法中最重要的一个参考。理论上,你的页面标题要独一无二并尽可能多地包括页面内容中的关键词。你在浏览网页时可以从浏览器最上方看到一个网页的标题。
10. 元标签(Meta Tags)
元标签(Meta Tags)和页面标题一般,主要用于为搜索引擎提供更多关于你页面内容的信息。元标签位于HTML代码的头部,还有就是对长眼睛的访客是不可见的。
11. 搜索算法(Search Algorithm)
Google的搜索算法是为了给每一次搜索请求找到最为相关的网站和页面而设定。这个算法考量的因素超过200种(谷歌自称),其中包括页面等级、标题、元标签、网站内容,以及域名的年龄等。
12. 搜索结果页面(SERP)
搜索结果页面(SERP)的英文全称为Search Engine Results Page.基本上,这就是你平时在Google键入关键词回车后的页面了。你的网站从这个页面得到的流量取决于你的网站在搜索结果中的排名等级。
13. 沙盒(Sandbox)
Google除了所有网站的索引之外,还有一个单独的索引沙盒,那里面是新近发现和收录的网站。当你的网站存在这个沙盒之中时,它就不会在一般的搜索结果中出现,而只有当Google确认了你的网站是合法的,这才会将其从沙盒中移出进入所有网站的索引。
14. 关键词密度(Keyword Density)
如何判断一个特定页面的关键词密度?你只要将一个关键词使用的次数除以页面的总词数就可以了。关键词密度过去是搜索引擎优化中非常重要的一个因素,因为早期的搜索算法对此十分看重,但现在已经时过境迁了。
15.关键词堆积(Keyword Stuffing)
因为早期搜索算法对关键词密度非常看重,站长们便通过使用人工堆积关键词的手法来作弊和蒙骗搜索引擎。这种手法就叫做关键词堆积,当然现在已经没用了,而且你还可能会因此受到惩罚。
16. 障眼法(Cloaking)
障眼法(Cloaking)是指利用代码在同一个页面上让机器人和真人看到不一样的内容。其目的是为了让页面通过关键词而提升页面评级,而真正的目的是推销和出售各种不相关的产品或服务。当然,这也是一种作弊的手段,有很大可能会受到搜索引擎惩罚,甚至剔除。
17. 网络爬虫或网络蜘蛛(Web Crawler)
网络爬虫或网络蜘蛛(Web Crawler)也简称为爬虫或蜘蛛,代表搜索引擎在网路上进行浏览,目的是发现新的链接和页面,这是进行索引的第一个环节。
18. 复制内容(Duplicate Content)
复制内容(Duplicate Content)也叫“重复内容”,通常是指一个页面在引用了站内或站外的大段实质内容,或者是存在完全相同和极其相似的情况,而这也是一个网站应该尽量避免发生的情况,否则很容易让你的网站受到惩罚。
19. 标准链接(Canonical URL)
标准链接(Canonical URL)是指一个网页的链接要符合规范和标准。
20. 机器人协议(Robots.txt)
机器人协议(Robots.txt)不过是一个TXT文本文件,存在于你域名根目录之下,作用是将网站的目录结构信息告诉爬虫和蜘蛛,并限制其对特定文件夹和内容的访问,或者是完全将它们关在门外。

Monday, January 10, 2011

NLB - Load Balancing and Other Issues....

http://www.hanselman.com/blog/LoadBalancingAndASPNET.aspx

http://technet.microsoft.com/zh-cn/library/bb742455%28en-us%29.aspx

http://support.microsoft.com/ph/3198/zh-cn?sid=770&aid=1&GSA_AC_More1
NLB配置中单播与多播区别
http://hi.baidu.com/hneli/blog/item/656725d3e5471433970a16bd.html

Using NLB with ISA Server Part 2: Layer 2 Fun with Unicast and Multicast Modes

关于负载能力的说明
http://blog.sina.com.cn/s/blog_4b506acf0100g2x6.html

Unable to connect to Windows Server 2008 NLB Virtual IP Address from hosts in different subnets when NLB is in Multicast Mode
http://blogs.technet.com/b/networking/archive/2009/01/15/unable-to-connect-to-windows-server-2008-nlb-virtual-ip-address-from-hosts-in-different-subnets-when-nlb-is-in-multicast-mode.aspx

单播模式下的单个网络适配器
http://technet.microsoft.com/zh-cn/library/cc757150.aspx
单播模式下的多个网络适配器
http://technet.microsoft.com/zh-cn/library/cc786134.aspx

Tuesday, January 4, 2011

Godaddy.com How to Register Own Nameservers / Hosts

It's hard to find out ...but if you intend to set up your own Domain Name Server (DNS) service, you can register your own hosts using these instructions. You can enter up to 13 hosts, depending on the maximum number of hosts the top-level domain name (TLD) registry allows.

o Register Your Own Domain Hosts

  1. Log in to your Account Manager.
  2. In the My Products section, click Domain Manager.
  3. Click the domain name you want to use to register as your own nameserver.
  4. In the Host Summary section, click add.
  5. In Host name, enter the host name you want to register.
    NOTE: The value entered here will be appended to your domain name to create the host name. Do not use the 'www' prefix. Example: For the domain name coolexample.com, entering 'ns1' here results in ns1.coolexample.com.
  6. In the Host IP fields, enter the IP address(es) you want to add to the host.
    NOTE: If your server has only one IP address, you can use the same IP address for multiple hosts except where forbidden by the domain name's registry.
  7. Click OK.
It takes 4 to 8 hours to register hosts for .COM and .NET domain names and 24 to 48 hours for all other domain name extensions.

Wednesday, December 29, 2010

How to improve home wireless network performance

If Windows ever notifies you about a weak signal, it probably means your connection isn't as fast or as reliable as it could be. Worse, you might lose your connection entirely in some parts of your home. If you're looking to improve the signal for your wireless network, try some of these tips for extending your wireless range and improving your wireless network performance.
10 tips for improving your wireless network

1. Position your wireless router (or wireless access point) in a central location

When possible, place your wireless router in a central location in your home. If your wireless router is against an outside wall of your home, the signal will be weak on the other side of your home. Don't worry if you can't move your wireless router, because there are many other ways to improve your connection.
Bad router and good router comparison

2. Move the router off the floor and away from walls and metal objects (such as metal file cabinets)

Metal, walls, and floors will interfere with your router's wireless signals. The closer your router is to these obstructions, the more severe the interference, and the weaker your connection will be.

3. Replace your router's antenna

The antennas supplied with your router are designed to be omni-directional, meaning they broadcast in all directions around the router. If your router is near an outside wall, half of the wireless signals will be sent outside your home, and much of your router's power will be wasted. Most routers don't allow you to increase the power output, but you can make better use of the power. Upgrade to a hi-gain antenna that focuses the wireless signals only one direction. You can aim the signal in the direction you need it most.
Standard antenna and hi-gain antenna examples

4. Replace your computer's wireless network adapter

Wireless network signals must be sent both to and from your computer. Sometimes, your router can broadcast strongly enough to reach your computer, but your computer can't send signals back to your router. To improve this, replace your laptop's PC card-based wireless network adapter with a USB network adapter that uses an external antenna. In particular, consider the Hawking Hi-Gain Wireless USB network adapter, which adds an external, hi-gain antenna to your computer and can significantly improve your range.
Laptops with built-in wireless typically have excellent antennas and don't need to have their network adapters upgraded.

Wireless router and wireless repeater

5. Add a wireless repeater

Wireless repeaters extend your wireless network range without requiring you to add any wiring. Just place the wireless repeater halfway between your wireless access point and your computer, and you'll get an instant boost to your wireless signal strength. Check out the wireless repeaters from ViewSonic, D-Link, Linksys, and Buffalo Technology.

Wireless channels

6. Change your wireless channel

Wireless routers can broadcast on several different channels, similar to the way radio stations use different channels. In the United States and Canada, these channels are 1, 6, and 11. Just like you'll sometimes hear interference on one radio station while another is perfectly clear, sometimes one wireless channel is clearer than others. Try changing your wireless router's channel through your router's configuration page to see if your signal strength improves. You don't need to change your computer's configuration, because it'll automatically detect the new channel.

7. Reduce wireless interference

If you have cordless phones or other wireless electronics in your home, your computer might not be able to "hear" your router over the noise from the other wireless devices. To quiet the noise, avoid wireless electronics that use the 2.4GHz frequency. Instead, look for cordless phones that use the 5.8GHz or 900MHz frequencies.

8. Update your firmware or your network adapter driver

Router manufacturers regularly make free improvements to their routers. Sometimes, these improvements increase performance. To get the latest firmware updates for your router, visit your router manufacturer's website.
Similarly, network adapter vendors occasionally update the software that Windows uses to communicate with your network adapter, known as the driver. These updates typically improve performance and reliability. To get the driver updates, do the following:

Windows 7 and Windows Vista

  • Click Start menu, click All Programs, and then click Windows Update.
  • In the left pane, click Check for updates, and then wait while Windows Vista looks for the latest updates for your computer.
  • Install any updates relating to your wireless network adapter.

Windows XP

  • Visit Microsoft Update, click Custom, and then wait while Windows XP looks for the latest updates for your computer.
  • Install any updates relating to your wireless adapter.


9. Pick equipment from a single vendor

While a Linksys router will work with a D-Link network adapter, you often get better performance if you pick a router and network adapter from the same vendor. Some vendors offer a performance boost of up to twice the performance when you choose their hardware: Linksys has the SpeedBooster technology, and D-Link has the 108G enhancement.

10. Upgrade 802.11b devices to 802.11g

802.11b is the most common type of wireless network, but 802.11g is about five times faster. 802.11g is backward-compatible with 802.11b, so you can still use any 802.11b equipment that you have. If you're using 802.11b and you're unhappy with the performance, consider replacing your router and network adapters with 802.11g-compatible equipment. If you're buying new equipment, definitely choose 802.11g.
Wireless networks never reach the theoretical bandwidth limits. 802.11b networks typically get 2-5Mbps. 802.11g is usually in the 13-23Mbps range. Belkin's Pre-N equipment has been measured at 37-42Mbps.

关于域名DNS解析中TTL的设置时间

网上关于域名dns解析中ttl值设置时间的文章不多,我今天遇到了这个问题,就把这个问题整理一下,希望可以给需要的朋友有所帮助。
什么是域名的TTL值?
TTL(Time-To-Live),就是一条域名解析记录在DNS服务器中的存留时间。当各地的DNS服务器接受到解析请求时,就会向域名指定的 NS服务器(权威域名服务器)发出解析请求从而获得解析记录;在获得这个记录之后,记录会在DNS服务器(各地的缓存服务器,也叫递归域名服务器)中保存 一段时间,这段时间内如果再接到这个域名的解析请求,DNS服务器将不再向NS服务器发出请求,而是直接返回刚才获得的记录;而这个记录在DNS服务器上 保留的时间,就是TTL值。
      域名DNS分两种,一种是权威域名服务器,域名注册商的服务器都为权威域名服务器,TTL值只能在权威服务器修改,还有一种域名解析服务器就是缓存DNS 服务器,比如各地ISP上网设置的DNS服务器,它的作用主要是把域名解析结果缓存到本地,方便你查询。域名DNS的TTL值实际上就是各地的DNS缓存 服务器多久去你的权威域名解析服务器(NS)获取一次你域名的解析IP。
那么域名解析的TTL只应该设置为多少合适呢,下面有两个建议,你可以结合自己参考一下:
一.增大TTL值,以节约域名解析时间,给网站访问加速。

一般情况下,域名的各种记录是极少更改的,很可能几个月、几年内都不会有什么变化。我们完全可以增大域名记录的TTL值让记录在各地DNS服务器中缓存的 时间加长,这样在更长的一段时间内,我们访问这个网站时,本地ISP的DNS服务器就不需要向域名的NS服务器发出解析请求,而直接从缓存中返回域名解析 记录。

国内和国际上很多平台的TTL值都是以秒为单位的,很多的默认值都是3600,也就是默认缓存1小时,这个值实在有点小了,难道会有人一个小时就改一次域 名记录吗?你可以根据自己的需要把这个值适当的扩大,例如要缓存一天就设置成86400。Godaddy的TTL设置比较直观,但总共只有5个值可以选 定,即时切换到高级设置模式也是如此,有点死板了。


二.减小TTL值,减少更换空间时的不可访问时间。

     更换空间99.9%会有DNS记录更改的问题,因为TTL缓存的问题,新的域名记录在有的地方可能生效了,但在有的地方可能等上一两天甚至更久才生效。结 果就是有的人可能访问到了新服务器,有的人访问到了旧服务器。如果原来的域名TTL值设置的小,各地的ISP域名缓存服务器服务器就会很快的访问你域名的 权威DNS解析服务器,尽快把你域名的DNS解析IP返回给查询者
     这就是说你如果想要解析速度,各地ISP的DNS服务器缓存你的域名,你就需要把TTL值设置大一些,如果你想域名更换空间或者IP后能尽快解析到新的 IP上,就需要把TTL值设置小一些。(我今天因为一个域名过期忘记续费被停掉了解析,结果域名被美国的根库修改了DNS,并把域名转到一个域名停放页 面,后来联系注册商才发现这个问题,由此引起了我对域名的思考,考虑到了域名DNS 解析中TTL值的问题。小插曲,和本文的技术无关)
     总结:对于IP地址相对固定,或短期内不会变更IP地址的用户来说TTL值设置的大些如几个小时或更大些为宜。调大TTL值可以显著的提 高域名的解析稳定性和速度。而对于近期有计划变更IP地址的用户需要提前把TTL值改小,以便使缓存在世界各地DNS服务器上的旧域名记录迅速过期,等 IP地址固定下来后再把TTL值改大。
    经验:百度和google的域名TTL值我看了一下,都是86400秒,也就是一天。我的一些域名我也修改成了86400秒了,你的具体多大,你自己根据需要修改吧。


source: http://www.dabaoku.com/jiaocheng/fabu/yuming/201009207014.shtml