Dec 15, 2009

Create a sharpoint webpart in Visual Studio 2010

Creating a web part becomes much easier with Visual Studio 2010 (beta 2). The structure is a dummy web part which simple load a user control:;

In theory, a control can be added through

  • dynamically in CreateChildControls() of web part file

  • declarative in ascx file of user control

  • dynamically in Page_load() of user control's code behind

adding a custom property is very easy now, all need to do is add the following 2 attributes to any property: [WebBrowsable(true), Personalizable(true) ]

in .webpart, you can add default velues just as any other OOB properties

As custom properties are open to injection of user script (good or bad), SharePoint 2010 introduce 2 new flags to enforce security at both webpart level and property level:

SafeAgainstScript attribute in

[RequiresDesignerPermission] attribute for web part's property

see here for more details

Dec 11, 2009

Create a custom SharePoint application page and use ECMAScript ClientOM

You can create a full-blown Application Page with a dll by using VS 2010, see this blog for details. Or you can follow the simple steps to create it without VStudio:

* copy from any application page from layouts/

* delete all contents in <asp:Content id="PlaceHolderMain" >

*change the page inheritance to: Microsoft.SharePoint.WebControls.LayoutsPageBase

*Find the buttons template section:


<asp:Button UseSubmitBehavior="false" runat="server"

class="ms-ButtonHeightWidth" OnClick="BtnUpdateWeb_Click"

Text="<%$Resources:wss,multipages_okbutton_text%>" id="BtnCreate"



* Define OnClick function.
<script runat="server">

protected void BtnUpdateWeb_Click(object sender, EventArgs e) { ...}

</script >

*Note: The above template also defines both "OK" and "Cancel" buttons on the page.

by now, it should be a functioning application page, and you can load ClientOM by adding the follwoing in any asp:content:

<SharePoint:ScriptLink runat="server" Name="sp.js" OnDemand="true" Localizable="false" />

Then you can use ClientOM in any javascrip such as:

function retrieveWebSite() {

var clientContext = new SP.ClientContext.get_current();

this.oWebsite = clientContext.get_web();

clientContext.load(this.oWebsite); //this is to make oWebSite available in client




Dec 3, 2009

SharePoint Content Deployment

Recently I have deployed sharepoint content from 32 bit window 2003 to 64 bit window 2008, here are some pitfall I ran into:

  • Target SharePoint server has to be configred to accept "incoming content deployment jobs" and check "Do not require encryption" if SharePoint Central Admin site is not using SSL;
  • Target SharePont site collection has to use blank template;
  • Deploymentmanifest.xsd (under 12 hives\Template\xml on Target SharePoint Server) has to add the followings (this only requires for 32 to 64 bit mix)

<xs:attribute name="AllowAutomaticASPXPageIndexing" type="xs:boolean" use="optional" >
<xs:attribute name="ASPXPageIndexMode" type="xs:string" use="optional" > < xs:attribute name="NoCrawl" type="xs:boolean" use="optional" >
< xs:attribute name="CacheAllSchema" type="xs:boolean" use="optional" >

Nov 17, 2009

RSS Viewer web part bug

If you want to use RSS Viewer web part for private/authenticated feed, you need enable Sharepoint Kerberos authentication. Otherwise you get error: "The RSS webpart does not support authenticated feeds" even the feed from its own site.(update 03/31/2010:
  • on window 2008, it can view authenticated feeds from its own site, but it is win2k8 only. on both window 2003 and window 2008 R2, it requires SPN registration (delegation not necessary) and Kerberos in order to view authenticated feeds;
  • if both feeds and RSS Viewer on the same server, only consuming web application (RSS Viewer host) needs Kerberos even if feeds are from other web application with different application pool;(on window 2008, it only requires IIS kerberos setting, no SPN needed)
  • the above apply for both moss and sharepoint 2010;

When you view a private feed, you may also get the following error:

"An unexpected error occured processing your request. Check the logs for details and correct the problem."

It happens when you use a non-default zone URL for sharepoint site: (update 03/31/2010: this appears not to happen on sharepoint 2010 beta2)

With AAM setting like this:

It works if using the default zone URL:
(update 03/31/2010) Reference: SharePoint 2010 and Kerberos by Spence Harbar

IIS 7 Kerberos authentication for SharePoint

IIS 7 has a new feature called Kernel Mode Authentication, it can be found off "Advance Settings.."

In order for SharePoint to use Kerberos authentication, it has to be disabled: (update 04/01/2010: sharepoint 2010 disable this by default!!)

This is necessary because Kernel Mode can't work with multi-server sysem where you can't register same SPN to multiple server accounts.

see here for IIS authentication negotiation process

NONONO In IIS 6, as long as NTAuthenticationProvider is set as "Negotiate, Kerberos", whether SPNs are registered or not, server granted Kerberos authentication. But IIS 7 seems to be of SPN awareness during negotiation regardless of Kernel Mode on or off: it only agree on Kerberos when the App Pool ID account has SPN registered, otherwise it falls back to NTLM.

add custom sharepoint web service in VS 2008

This article gives all you need to create a custom web serice in SharePoint 2007. But when adding a custom service in Visual Studio 2008, get the following error:

It turns out you have to append ?WSDL :

A custom sharepoint web service needs to be put in _vti_bin to be trusted. Otherwise either SharePoint trust level or CAS policy need to be modified.

Sep 23, 2009

SPGridView Paging and Filtering

A common issue with SPGridView is to enable paging: the PagerTemplate property of SPGridView needs to be set as null. If the SPGridView is declaratively defined in aspx page, the following code won't enable paging:

<sharepoint:spgridview id="SPGridView1" runat="server" >
<pagertemplate ></pagertemplate>

instead the following code works:

protected override void OnLoad(EventArgs e)
SPGridView1.PagerTemplate = null;

After paging is enabled, another common issue is, filter is off after navigating pages. I know filter is off acturally on every subseqent postback, like sorting. But to some degrees, it makes senses to turn it off since users are given no indication that a filter is on otherwise, which can certainly cause some confusion. But turning filters off on paging is very unsatifactory.

Inspired by the idea in this post, here is what I did to enable filtering across pages (based on .Net 3.5):

first cache filter settings :

protected override void OnPreRender(EventArgs e){

ViewState["FilterExpression"] = ObjectDataSource1.FilterExpression;



secondly, set filterexpression when postback is from pagings:

protected override void CreateChildControls() {

arg = (string)req.Form["__EVENTARGUMENT"];
if (arg.StartsWith("Page$") && ViewState["FilterExpression"] != null)

ObjectDataSource1.FilterExpression = ViewState["FilterExpression"].ToString();


related reference: (.Net 2.0) (.Net 3.5)

Sep 7, 2009

Activating Sharepoint Timer Job

The best pratice to create a custom sharepoint timer job is to create a feature with web application scope and to instantiate a SPJobDefinition there. This is becuase it is application pool id's credentail that is used during feature activation, and only central admin pool id which is farm account has sufficient privilege.

When activating from other web application whose pool id is not farm account (by best practice, it should not), you may see one or both errors as follow:

  • In browser, "unknown error" and in window event log, "EXECUTE permission denied on object 'proc_putObject' "
Cause: application pool id doesn;t (and should not) have write permission to config database

Workaround: assign application pool id as db_owner of sharepont config database

After that, you might get anohter error (if the app pool id is not sharepoint server local admin) when you try to activate (with permission on config database, you can now unactivate feature, but not activate)
  • In browser, "HTTP 403 error (someone saying 404 error), and in ULS log, "...Microsoft\SharePoint\Config\bd189eb6-92d0-4ca5-87b0-770f542e3f0a\cache.ini' is denied"
Cause: Sharepoint need to cache timer jobs in WFE (so it doesn't need to get them from sql as often as every minute) and app pool id (in WSS_WPG group) doesn't have that file permission. In contrast, farm account in WSS_Admin_WPG has full permission on the folder of "C:\Documents and Settings\All Users\Application Data\Microsoft\SharePoint".

Workaround: assign full control permission to application id for that folder or add app pool id into WSS_ADMIN_WPG group.

But the real solution is to activate timer job feature in the central admin, which means you need to create a feature of web application scope.

Sep 3, 2009

SharePoint databases part 2

part 1 outlines sharepoint databases and database backup. This part will focuse on secrity: what sharepoint accounts have access to sharepoint databases and in what roles.

SharePoint_config database:

  • install account is its dbo
  • farm account (and local admin) in db_owner role
  • application pool account in WSS_Content_ApplicationPoolid role

Central_Admin database:

  • same as config except that local admin is not in db_owner role

Content database:

  • farm account is dbo
  • app pool account and ssp service account are in db_owner role

SSP (and SSP Search DB):

  • same as content database, plus search service account is in db_owner

Server Roles:

  • Install account has dbcreator fixed server role & securityadmin fixed server role.
  • Farm account has the same fixed server role, but it is automatically configured.
  • other service only has public server role.

Understanding those and sharepoint application pool id (see this) can help to solve a lot sharepoint database permission issues such as :EXECUTE permission denied on object 'proc_putObject' in event log tells that the application pool id doesn't have write permission on configure database.

Aug 13, 2009

HTTP authentication on redirect

I recently had a hard way understanding Http authentication particularly involving redirect. After googling and conversing with a good friend, Alan, here is the picture on what will happen when server A (or browser)makes a http request to server B which redirects to server C:

  • Server A: Request.Credentials = CredentialCache.DefaultCredentials Sent request to Sever B
  • Server B: returns 401 – List of login schemes supported From Secured web page
  • Server A: Sends Request + Request.Credentials (formatted according to the selected login scheme) to Server B
  • Server B: returns 302 – "Redirect to Server C"
  • Server A: Request sent again to Server C
  • Server C: return 401 – List of login methods supported From New secured web page
  • Server A: Request + Request.Credentials (formatted according to the selected login scheme) to Server C
  • Server C: returns 200 – Content From New secured web page

Why auth handshake always happen even if the credential is set? This is by design, because Httprequest clients have no idea what auth schema the remote server is using. You can avoid first auth handshake by manually setting HttpRequest's header, like: req.Headers.Add("Authorization", "basic " + base64); But this needs to be done every time even for same Uri-Pref. Generally allowing handshake and setting PreAuthentication=true is better. See this post for details.

When making HttpRequest, HttpRequest object need to have a CookierContainer, which will be used by HttpResponse to fill in. It doesn't do anything with authentication though.

Another thing related is, in case of impersonating, Kerberos (both authentication and delegation) is required in order to forward default credentials (double hoppings).

Aug 10, 2009

core.js in sharepoint master pages

in sharepoint default.aspx file, core.js is loaded as deferred:
<sharepoint:scriptlink language="javascript" name="core.js" Defer="true" runat="server" / >

in layouts/application.aspx, it is loaded without deferred:
<sharepoint:scriptlink language="javascript" name="core.js" runat="server" >

The impact of this difference is, you can override javascript functions in application pages (layouts pages), but you can't do that to site pages.

Jul 29, 2009

SharePoint Page Provision

In SharePoint, there are 3 kinds of pages you can provision:

Application Page-- Pages in _layouts/ directory

Site Page-- ghosted site pages such as default.aspx

pages loaded in sharepoint document libraries

For pages in sharepoint document library, no server code is allowed by default, unless you change PageParserPaths in web.config. See this blog for details.

For both Application Page and Site Page, you can add server code in one of 3 ways:
  • inline code (code render or declartion blocks)
  • add user controls, for example: <%@ Register TagPrefix="XXX" TagName="lookup" Src="~/_controltemplates/LookupDefaultValue.ascx" % >
  • inherits from code behind. Such as : <%@ Page inherits="CodeBehindDemo" % >. The trick is SharePoint dones't allow either CodeBehind or Src attributes. You have to use dll instead:
<%@ Assembly Name="NIAID.ListEventSetting, Version=, Culture=neutral, PublicKeyToken=a1c61a650ab8c476"% > <%@ Page Language="C#" Inherits="NIAID.ListEventSetting.ListEventPage" MasterPageFile="~/_layouts/application.master" % >

controls or methods used in aspx page need to be defined in the code behind with either protected or public access.

for site page, the dll also need to be in the safe control list in web.config.

Another option, less desired, is to use  CodeFile attribute in Web Site Project. It requires putting .cs source files into the layouts directory. Some people even developed user controls with CodeFile in layouts or controltemplate and use SmartPart or self-developed webpart loader (loadControl) for web part development.

Jul 25, 2009

Configure and Test SharePoint Incoming Email in Window Server 2008

I have built a Win2k8 based sharepoint 2007 farm (1 WFE, 1 Index and 1 SQL), and have its incoming email configured as follows:

1.install SMTP in both WFE( for incoming email) and Application Server (for outgoing email);

2.check services in CA to make sure WFE is running "incoming email service" and Application Server is running "outgoing email service";

3. Create a DNS MX record such as:
(same as parent folder) MX [10] spweb.sp.local or
moss MX [10]spweb.sp.local
this essentially tells spweb.sp.local is the mail server for the domain of sp.local or subdomain moss.sp.local. read here for more details.

4. Configure mail server's SMTP domain list to include an alias of sp.local (for normal user email address, used to test SMTP extension/pop3) and an alias of moss.sp.local for sharepoint email enabled lists:
5. Configure "incoming setting" in CA
  • allow farm to receive email
  • specify email address such as moss.sp.local
6. Configure list setting to allow list get emails
  • specify email address for a sharepoint list, such as sharedDoc@moss.sp.local
  • check "yes" on "Save original e-mail"
7. Configure an email client (outlook).
  • install SMTP extension (pop3). This is a necessary (and hard) part since Win2k8 doesn't have POP3 built in.
  • open window firewall at port 110 (for pop3)
  • create an outlook account for testing:
    * Email address ends with one of SMTP domain alias list such as admin@sp.local
    * setting smtp server (not confused with sp outgoing eamil server) and pop3 server (iP address, not Netbios)
    * user password to logon to pop3 server (defined in smtp extension's configure.xml located in "c:\ProgramData\ppedv\visendosmtpextender")
8) Test first if sending and receiving email work okay in outlook by sending some email to itself, and then test sending email to a sharepoint list such as shareddoc@moss.sp.local.

Overall, the very simiplied picuture is: mail client asks its local SMTP to send an eamil to shareddoc@moss.sp.local)-> outlook's local SMTP server ask DNS,who is mail server for remote domain sp.local ? -> find MX record from DNS ->logon to remote mail server SMTP-> check for mail domain moss.sp.local: if it doesn't exisit, mail sending fails there. If it does exist, mail goes to SMTP's drop folder and stay there waiting for SharePoint Timer Job to pick up and put into the assocaited list. For regular user email, mail client using POP3 will do the pickup job, and the only difference is regular user email has its individual subfolder under the drop folder root.

Jul 23, 2009

Moss 2007 and Server 2008 window firewall

I have installed MOSS 2007 on a farm of 3 window 2008 servers:
There are serveral problems all related with window firewall:
  • can't browse Central Admin from anywhere other than Application server

Window Firewall only open Http at port 80. open an exception at CA port in App server to fix this problem.

  • Office Search Service or SSP can't be configured

Sharepoint SSP use web service call at port 56737. open exceptions on both WEF and App servers to fix this problem. If no query server is specified, configuration "looks like" it can go through, but "check service enabled in farm" disclose problems. Be sure to check it.

  • Index Propagation fails

Sharepoint use SMB (File Shareing) protocol to push index from Index to Query server (WFE in this case). Open "File and Printer SharePoint" exception to fix this problem.


Jul 19, 2009

Window Server 2008, Hyper-V and Wireless Connection

In preparation for SharePoint 2010, I need to convert a 64-bit Vista Workstation into a server runing window 2008 and then run Hyper-V to create a farm of 3 servers: a Domain Controller, a SQL server, and one Web server. My another goal is to setup all wireless network connection for all VMs and my physical server. Here are the outlines on some major steps:

1) Convert Vista to Win2k8.
Booting with Win2k8 CD. There are choices of either formating disk or replacing Vista. I chose the latter since I don't need to install drivers again.

2) Setup wireless connection
First need to enable wireless feature for win2k8:
Secondly need to update wireless driver: no Window 2k8 wireless driver availabe, but I can use Vista's driver: the win2k8 installation process save all vista drivers in Windows.old folder. I use "Update Driver" option in Device Manager:
3) enable RDP.
Since I build this as my work platform, I need to access anywher via RDP:
  • need to Change "Remote" Option: Computer->Properties->Remote Setting->Remote
3) setup Hyper-V
4) Create VMs
First time when I created VMs, they don't have any network connection even if I have wireless connection for my phsical server. It turns out Hyper-V doesn't support wireless adapters. The workaround is:
  • create a virtaul network in Hyper-V's Virtual Network Manager and then bridge it with wireless connection (details).
  • Then run Hyper-V to create VMs with the virtual network connection created above.
For DC vm I chose mini requirement: 512MB memory and 32G disk.
Since I also want to RDP from my phsical server to VMs ( I can certainly connect to them, but if I RDP to my server first and then connect to VMs, window key combination can't go through to VMs) , I enabled RDP as I did to my physical server. But to my surprise that only allows me to use IP address! When i use VM BIOS, it said it can't find the server! I looked at my router's DNS, the VM BIOS name is not there. and I can't add it (get "entry already exist" error) for some reasons. As a workaround I open Window FireWall for PING (see here on how to ping), and I can then RDP its BIOS name.
5) promote Domain Controller
  • run dcpromo.exe (detail)
  • disable IP6 for DC vm's connection and configure IP4:
    • since my server is From DHCP, DC vm need a static IP address and its DNS server should point to itself details
            6) join other VMs to Domain
            I have create other 2 VMs also runing Win2k8, and need to join them to the Domain I just created. To do so, the only trick is to set each VM's DNS server to DC/DNS VM IP(otherwise it will go to my home router's DNS instead), and then change WorkGroup to Domain just like changing computer's BIOS name. DC will add VM server into AD once it is joined, and DNS server will dynamically add VM's name into dns table once VM is connected.

            by now I have a farm of 3 virtual servers running on a sub domain (or virtual sub net). It was a long weekend, but I am so happy about Hyper-V. It really rocks!

            Jul 15, 2009

            SharePoint Managed Path and IIS ISAPI

            In SharePoint 3.0 there is no more extra ISAPI extension such as the one in WSS 2.0. All requests are routed to aspnet_isapi.dll instead.

            The aspnet_isapi.dll will serve a request if a physical IIS path is found as a match. For example, in IIS you can create a subfolder out of root directory of sharepoint site, and you can browse files inside the subfolder. Doing this actually blocks this subfolder name as sharepoint managed path, since IIS handle requests first.

            If no physical IIS path found, Http handlers and Http Modules which are defined in the web.config will start to knick off to handle http requests. At this point, the managed path info will be used to resolve URL.

            Update 04/05/2010: IIS will do authentication,and after that the request is yielded to the SharePoint14Module, which will contact file system first and then content database for appropriate page. See this blog for details.

            There is an exception: if you put files (other than folders) under iis root directory of sharpoint site, those files can not be served unless they are defined as Explicit Inclusion type of managed path. This seems to be the wss 2.0 "excluded" concept.

            Update: this exception only applies to MOSS and WSS 3.0, it is fixed in SharePoint 2010. great fix, no more confusing.

            Jul 13, 2009

            SharePoint and WebDav

            Web-based Distributed Authoring and Versioning, or WebDav is to allow clients to access web-based documents as if they are in client's local driver (accessible via window explorer: yoursite/DavWWWRoot ). SharePoint features such as Explorer View is an example, saving office files into sharepoint server is another example. IIS has WebDav service, however SharePoint doesn't use it, instead, SharePoint has its own built in. So there is no need to enable IIS WebDav service in a sharepoint server.
            On the client side, there are some requirements:
            • need Office 2007 installed;
            • Windows XP: Web Client is installed and enabled (by default).
            • Windows Vista: The Web Folder service needs to be started.
            • Windows 2008 (and R2): The Desktop Experience feature needs to be installed.
            In case of FBA SharePoint sites, clients also need to
            • enable "client integration"
            • enable Cookies by checking "Auto sign me"
            • window XP need to install hot fix Webfldrs-KB907306-ENU.exe
            SharePoint Users also need the following permission (this is a part of "contribute" level permission, be default assigned to "member" shaerpoint group) to utilize any WebDav related feature:

            Jul 1, 2009

            SharePoint Authentication and IIS

            We know SharePoint relies on IIS to do authentication (unless FBA), and provides contents based on AAM configuration. When a request such as hits a WFE, the IIS select a site to authenticate the request. The selection process works as follows:
            1. first it looks for the site listening to port 80 with header as If it is found, it is selected;
            2. Otherwise, it looks for the site without any header and listening to any unsigned ip address at port 80. If there is one, it will be selected for authentication;
            3. If neither is found, IIS error out

            Notice the URL doesn't have to point to the WFE. for example, in the case of Load Balancer, URL points to LB, not WFE.

            After authentication succeed, It is up to SharePoint to serve the http request. SharePoint provides content solely based on its AAM configuration, i.e, it must have that specfic FQDN configured (in the prvious example, it is, otherwise, it errors out.

            Notice in some scenario, IIS site which does authentication can have a different FQDN than that in SharePoint AAM.

            AAM reference:

            Jun 25, 2009

            SharePoint databases part 1

            It is long time since I started to wonder what databases SharePoint is using, and today I finally spend some time on this and get some clarifications:

            1) SSP database and SSP search database. These 2 databases are tied with your individual SSP, and they are backup and restored with SSP. For backup and restore SSP, see This KB;

            2)Content Database for SSP site and/or MySite: When you create your SSP,if you setup individual web applications for your SSP site and/or MySite , you will have 2 more extra content databases. But they need to be backuped and restored individually. They are content databases.

            3) Config database: this is most importanat database, and if moved to a different SQL server, the target sql server must have exact the same version number (SPs and KBs) applied to backup/restore operation, seems Log Shipping can overcome this restriction.

            4)Content Database for the Center Admin Site: This database name can't be modified and must be backup and restored with Config database. (Config DB name can be changed in registry: My Computer\HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Shared Tools\Web Server Extensions\12.0\Secure\ConfigDB)

            5)WSS search database. I am not sure what this datbase is used in MOSS since there is SSP Search database, is this for WSS Search as a legacy from WSS 2.0?
            but anyway, this database need to be backuped and restored individually. Actually every time when you restart Search Help in the central Admin, you need to recreate this database.

            6)Content database for portal sites. This is the database normally referred as "content databse".

            You can pretty much manually move (via SQL backup and restore) all databases but SSP related dbs, which will end with SSP related dbs stay in the old SQL server, and all others live in a new SQL Server. To move all sharepoint database? see this KB for SSP backup/restore and SQL Server Connection Alias. Be cautious, SQL Connection Alias can cause a lot confusions in the future.

            update: there is another db which draws more and more attentions as performance killer: TempDB. This db is particularly related with sharepoint indexing/crawling. For db related performance recommendation, see this post.

            Part 2 will focuse on sharepoint database permission.

            Jun 24, 2009

            Sharepoint Kerberos, really?

            when you change authentication type to Negotiate(Kerberos) in SharePoint central admin, all sharepoint do is to change NTAuthenticationProvider of sharepoint site in IIS to "Negotiate, NTML" from "NTLM". (how to find NTAuthenticationProvider value? see this post. If there are multiple WFEs in your farm, check each of them as I experienced a problem seeing the failure of setting this IIS meta data from SharePont Central Admin UI.).

            What does that mean? is Kerberos guaranteed? not really. Kerberose will be selected only if clients support Kerberos (such as "intergrated window authentication" checked in IE), and  SPN is registered (which make sure Kerberos is selected) and registered correctly (which make sure authentication will not fail)
            But how do you know for sure you have Kerberos functioning? I usually go to EvntView of server and in security log find event id = 540, and if you have logon type =3 and AuthenticationPackage = Kerberos. you are good to go.

            Jun 17, 2009

            Create PDF out of password protected web pages

            Recently a user tried to use Adob 9.0 to convert one web page from their intranet site into a PDF file, and got an authorization failure error even though she can browse the site in IE. And since she can sucessfully do this on their internet site, it seems that we need to give Adobe some sort of permission to read sharepoint site. But how?

            We know IE can browse sites without requiring users to enter password becuase of IE's credential passthrough, Adobe, unlike most of MS office product, doesn't have such functionality. But we can use IE's PDF boolbar to achieve credential passthrough:

            1.Browser IE to the desired secure site;
            2. IE view->toolbar->adobe PDF;
            3. “Convert” appears in the toolbar as follows:

            4. Choose "Convert Web Page to PDF.."

            you should be all set to go!

            May 4, 2009

            very large SharePoint Database Log files

            It is not unusual that you may find sharepoint databases have very large log files, sometimes they can be hundreds times of size of data file. The cause of this is:
            • the databases in "Full" recovery model, and
            • the log files have never been backed up ( this happens when doing sharepoint native backup, it only backups data, not log)
            When databases in a Full recovery model, neither full nor differential backup will truncate inactive segments in log files. Those segments thus can't be reused in the future, which causes the log file to continue growing without bound.

            The solution is,
            • turn recovery model to 'Simple' (for non-prod environment only), or
            • specifically backup Log files by using the following sql statement:
              • BACKUP LOG WSS_Content_80 TO DISK='z:\temp\80.log.bak'. The result of this is: when log backup is done, sql server automatically truncates all inactive transactions and allow those segments to be reused in the future.\
            • do Transaction Log back up on database. The T-log backup will automatically truncate log.

            However, the log file size will not be reduced until you shrink the log file size by sql statement:
              • DBCC SHRINKFILE ('Log_Logic_Name')
            you can find the log logical name by issue sp_helpdb or from UI.

            So to summary, the best practice is
            • Turn on "Simple" recovery model for Dev, and Keep "Full" model for Prod
            • do sql backup rather than sharepoint backup
            • full backup complemented by daily partial backup and then by hourly T-log backup

            Apr 22, 2009

            SharePoint Record Center

            This post outlines steps to route documents to record center and clarify some misunderstandings.
            1. Create a Record Center by using the record center template, it can be in the same web application as your source site or in a different web app. The latter is recommended;
            2. Establish the Connection to the Records Center: Central Administration-> External Service Connections section ->Records center. After this, your record center will appear to all document library's "send to" menu for any users who has read permission;
            3. Create a document libray in Record Center and Set up routing: Either the title or alias must be the content type name such as "document" or "form", and the location is the document library you created in the record center;
            4. users don't need any permission in the record center in order to submit recoreds. The only permission needed is the source site's application pool id (if it is different from the record center's pool id) has to be in the group of " Records Center Web Service Submitters for ...". Otherwise you will get the following error:

            "The ... records center could not be found or accessed"

            Apr 21, 2009

            IIS Error Message: Either a required impersonation level was not provided, or the provided impersonation level is invalid.

            If you got this error message when impersonating a logon user, you need to check your pool id and make sure it has "act as part of operating system" right.

            1. Open Control Panel > Administrative Tools > Local Security Settings.
            2.In the left panel, select Security Settings > Local Policies > User Rights Assignment.
            3. Open Act as part of operating system.
            4. In the Act as part of the operating system Properties dialog, click Add User or Group.
            5. IISReset

            Some documents say this is not necessary in Win2003, but it does happen when impersonating in the code.

            Other right of application pool (including Network Service):
            • Adjust memory quotas for a process
            • Generate security audits Log on as a service
            • Replace process level token
            • Impersonate a client after authentication
            • Allow logon locally
            • Access this computer from the network

            Apr 17, 2009

            data sharing cross SharePoint sites

            Recently there is a disucssion on how to share data cross sharepoint sites in the LikedIn SharePont user group. A lot people joined and shared ideas. I find a need to summary them up here as a reminder to myself.

            1) OOB solutions:

            2) recommeded 3rd party adds-on:

            • Coarseworks

            • LightingTools

            • CodePlex (lookup cross sites)

            3) customization:

            • roll-up web part

            • Search service and search result web part, xsl

            However, most of above apply to sites in a same collection. There is very limited options when trying to sharing data cross site collections, which indicates to me anothe point: when designing sharepont taxonomy, data shareing is a very import factor behind sizing and security.

            Mar 23, 2009

            Authentication process: Kerberos or NTLM? and delegations

            I ever post on how to register SPN. SPN is pretty much all needed for Kerberos authentication. The common misunderstanding is, authentication first try Kerberos, and if it fails, then try NTLM. Kerberos fallback to NTLM is referring selection process,not authentication itself. For example, when a client is trying to access server, NTLM will be selected if:
            • client such as IE has "Integrated window Authentication" unchecked (even if server IIS have NTAuthenticationProvider paramenter set to "Negotiate, NTLM": NTLM failback);
            • or server IIS have NTAuthenticationProvider paramenter set to "NTLM" (even if IE has "integrated window Authentication" enabled)
            • or SPN is not found from KDC
            IIS 5 has default setting as "Negotiate, NTLM", in IIS 6 NTAuthenticationProvider paramenter is not set, but IIS 6 use "Negotiate, NTLM" as default just like IIS 5.

            If both client and server support Kerberos (ie, server IIS has "Negotiate,NTLM" and IE support "Integrated window Authentication") kerberos will be selected.Negation starts: if client can get a ticket (SPN), it will send kerberos ticket, otherwise client will ask to use NTLMssp for authencation. if server doesn't have SPN, If client sends a wrong ticket, server will keep chanllenging client, and the result is: the authentication fail: server pop for password, but fail on any credentials. The authentication process can't fallback to NTLM at this point.

            One of common cases that client could get wrong tickets is, the request uses Netbios name such as http://servername/, http/servername is not registered, but Host/servername always exists. The result is client keep sending ticket for HOST/servername while server expect HTTP/servername ticket.

            Now it comes why we need delegation? You need delegation when you want to forward logon user's credential to another system. your ASP web needs to access resources in other server (double hop issue). This can happen when you have custom code to connect to anther SQL server, or you try to retrieve BDC data(other option for BDC is SSO), or you need to use Excel Service to display data from SQL report.

            First, how to get logon user's credential?

            • System.Net.CredentialCache.DefaultCredentials when impersonate=true
            • User.Identity.Name when it is not anonymous
            Second, how to hop?

            •  trust the server account (whatever it is, i.e, application pool, ssp service accout or mySite account etc) for delegation;
            • grant authenticated user (rather than service accounts) an access to target server/data.

            Need to turst Computer Account for delegation? No, but only when your service is running under network service, local service or local system. When configuring computer account for delegation, 1) registering specific service (option 3) rather than all service (option 2), see here for insturction; 2)reboot server to make it effective.
            Remember delegation has both timing and location constrains.

            here is the checklist for kerberos delegation

            Mar 21, 2009

            Add Javascript on SharePoint pages

            Some tips to inject javascript into sharepoint page:

            1) _spBodyOnLoadFunctionNames is a good friend. It will be called on page onload. So to make a javascript function call, you just need to put this


            and your function definition in a CEWP on any sharepoint page.

            2) toolpaneView=2 is the trick to insert CEWP on list forms such as Edit, View, New.

            3) delegate control with Id ="AdditionalPageHead" to add script cross pages.

            Implement this control with a user control in the /controltemplates, and the user control can control nothing but your custom javascript files under _layouts. For example, to include JQuery library:

            <%@ Control % >
            < script src="./_layouts/jquery-1.2.6.js" type="text/javascript" / >

            To use custom CSS files without modifying master page, see this post.

            Update 04/13/2010:
            4) Use CustomAction in Sharepoint 2010.

            SharePoint Kerberos: How to register SPN

            To enable Kerberos authentication for sharepoint, the first step is to register SPN for differernt serveice accout.

            1. SQl service account

            it should be in the following format:

            setspn -A MSSQLSvc/ accountname
            setspn -A MSSQLSvc/ accountname

            After that you can verify the kerberos by running the following query:

            select auth_scheme from sys.dm_exec_connections where session_id=@@spid

            note: you have to remotely connect to your SQL server, otherwise if you run SQL Studio inside the SQL server as I normally did, the above query always returns NTLM

            2 web application pool account:
            Assuming you have 2 web applications, one is at 80 and the other is at 8888.The best practice is to register in the format of:


            if a FQDN is used in place of Netbios, make sure FQDN is a A record in DNS, not a CNAME. CNAME will be translated into a different FQDN. How to find the type?

            >Set type=A (or CNAME)
            > your FQDN

            note: do NOT append append default 80, it will break if browser strips off 80, and also the bonus is it can make IE6 which doesn't append port number work without hotfix.
            for eaxmple, if a request is made from IE 6.0, IE 6 will compose SPN as http/ which happens to match the one registered. It can fail if HTTP/ is registered instead. If the same request is made from IE7, the SPN will be http/, and that is why we need the second format.

            Beaware though, after registering Http\NetBiosName, it will overtake Host\NetBiosName which can cause Http 401.1 error as described in this post.

            3. SSP service account
            Don't even bother to register SPN in the format of HTTP/. It won't work. You have to install Infrastructure Update or CU which includes IP,and then use the new custom format:

            Assuming SSP name is mySSP. read more here

            4. Farm Admin and My Site serveice accounts
            You can register them either using header or port number to avoid duplicates. It really should not matter, but normally people use port for Farm Admin, and use header for MySite.

            Note: if any service account is using newbiosname account(Network Service, Local Service and Local System), you don't have to set SPN for them, since they already have a SPN (HOST/netbioname) by default.

            with SPN registration done, you can verify kerberos authentication from the event logs. I will cover delegation in another post.

            This post is based on IIS 6.0 for ISS 7 please read here.

            Mar 19, 2009

            Sharepoint Application Pool ID Account

            SharePoint always impersonate authentication users in web.config by this entry: <entity impersonate="true" /> and it also has a Application Pool Account. What does this account do?

            1. In case Kerberos is used, this is the account that clients(such as IE) try to communicate with. This is why this account has be registered with a SPN for Kerberos authentication;
            2. In case you have custom code which need to hop to another server (SQL, File or any web service server), this account will forward login user credential(ticket in kerberos term) to the other server. This is why this account needs to be trusted for delegation;

            3. This is the account that sharepoint use to connect its own Content Database, which I bet is through a call RunWithElevatedPrivelege.

            A couple other things I learn about web application pool account:

            if you try to create an application from directly from IIS, you have to run:

            ASPNET_regiis.exe -ga domain\pollIdAccount

            if you use NetWork Service as pool id in window server 2k, you have to grant "Act as part of the operating system" privilege for impersonation to work. This is not necessary in Server 2003.

            All application pool id should be in the IIS_WPG group which grant most permission they need. See here for a full list permission IIS built-in accounts have.

            double hop issue and sharepoint sql communication

            double hop big picture: IE browser--->Web Front End----->SQL (0r any 0ther server)

            The double hop issue is all about passing window security token, so if you use SQL connection string, you don't have this annonying problem; or if
            your ASP Web uses trusted subsystem (instead of impersonation which is configured in the web.config: < identity impersonate="“true”/ >). In the case of trusted system, it is the web application pool account who hops (only 1) to another server.

            One of my colleagues responded this by asking, "why sharepoint doesn't have double hop issue when its WFE connects to its SQL database?"

            Well this is the question I don't know the answer to. We all know kerberos is not required for sharepoint, impersonate is the default setting in sharepoint web.config, and window authentication in SQL is default too. so I go to google, no found a direct answer though, the closest one is:

            < identity impersonate = “true” username=”Domain\UserName” password=”pword” / > can fix the problem.

            I went back to my sharepiont web.config, of course, I didn't see it. But it does shed light. If impersonation in web.config can fix this problem, then impersonation in code should have done the same thing. In Sharepoint, RunWithElevatedPrivilege is designed for network calls: this little guy impersonates Application Pool Account, and this account always has SQL access.

            I hope this bold assertion can trigger some interests on how sharepoint intra-farm communication work and someone can either confirm or correct it.

            Mar 16, 2009

            Share a Document Library among different sites

            There are many times people ask: how to share a whole document library among different sites? You can of course do with DVWP or CQWP, but neither of them gives a good user interface. You can also use LinkTo content type, but that is an item-by-item solution.
            There is a third addons: but it requires server access and intallation.

            We know list view web part can perfectly display a document library, but OOB it can only be added within same site. Is there a workaround?

            The answer is yes, since we all know we can convert List View webpart into DVWP, and then we can export to a .webpart file and then import it to any site in the collection.

            If you just do that, you will get a generic error. The problem is, in the .webpart file, only listId is specified, no WebUrl.

            We need to add WebUrl:

            1) open .webpart file in any editor
            2) search and find "ListID", there are 3 of them
            3) after each "ListID" add the followings:

            <asp:Parameter DefaultValue="siteName" Name="WebUrl" />

            After saving the change, import it to any site in the collection, you will see it works just like a charm.

            BTW, Even though you need to use SPD when converting LVWP to DVWP, you can avoid un-ghosting by deleting the page containing the initial LVWP.

            a great idea on how to deploy DVWP from one farm to another:

            Feb 16, 2009

            Hookup SharePoint outgoing email with your Email vendor

            update on window server 2008 configuration. First read this post. Following that post, you can setup sharepoint outgoing email IF your target email server accepts annonymos relay or don't need authentication from your sharepoint smtp server. But in case that you want to send to gmail or hotmail or like the following scenario where your company outsources email server to a third party, continue to read:

            I ever had a client who outsource their Email service to a vendor, and the vendor doesn't accept anonymous relay, in stead they require authentication. OOB there is no place for SharePoint to provide this info, can sharepoint outgoing email still be set?

            Yes, you can. Use sharepoint local smtp and configure its delivery outbound security:

            First change relay restriction:

            Then configure Security of outbound Delivery:

            There you have option to choose authentication mode and enter credentials.
            After that, you need to configure smart host by clicking "Advanced" button. Your mail vendor should provide your smart host name.

            update on Win2k8: IIS 7.0 SMTP setting has no effect on sharepoint mail outgoing. All you need to configure is IIS 6.o SMTP.
            update on sync of user AD info(including email): user AD data are sync-ed with sharepoint profile data by "profile import", and user info which are displayed on sharepoint team siteis actually stored content database, and are sync-ed with Profile data by 2 timer jobs:hourly Profile Syncronization and minutely Quick Profile Syncronization.
            So after you change AD data, you must do the followings before seeing new info on sharepoint site (such as email address for alert)
            1. import Profile;
            2. wait up to 1 hour for existing users,
            delete users from site collection and add them back in (to trigger Quick Profile Sync timer job, which only applies to newly added users)

            Jan 1, 2009

            FBA User Display Name

            After implemnting FBA in MOSS, in Welcome menu, account name such as "jsmith" rather than "joe smith" is displayed. Very often, people find it very annoying. In WSS, user can simple change the display name by editting "My Settings", but in MOSS, none of "My Settings" fields is editabe.

            Why? the reason is, In MOSS, the "My Settings" info comes from user profile. If your FBA data source is LDAP compatible, you can configur a custom profile import like this:

            *enigma is your FBA authentication provider name.

            after user profile import is finished, you should be able to see your FBA users with "Name" property containing friendly "displayName" (assuming you have it in your LDAP data source, for example, ADAM)

            You need to wait up to 1 hour for profile sync or my site cleanup timer job (see Spencer's article) to kick off (for profile sync, users need to be a site user in contrast to those user whose permission are assigned in application policy). Then close all your browser and log back in again, you will see friendly user display name in welcome menu.