following step i executed to fix the issue

1.Checked the solution store(Central Administration-->System Settings--> Manage farm solutions) and saw that the solution I was updating was not deployed and thrown error. The error it gave was not able to do GAC diployment of the dll. So i went to GAC and uninstall the WSPs related dlls  and deployed the wsps again from central admin.

2. From services.msc I stopped and restarted the SharePoint 2010 Timer service and the SharePoint 2010 Administration service.

3. Then i ran the power shell command again. this time the WSP got updated.

Hope this help , while any one of you face this issue.

Server Error '/'  Application

Object reference not set to an instance of an object

Description: An unhandled exception was generated during the execution of the current web request. please review the stack trace for more information about the error and where it orginated in the code.

Exception Details: System.NullReferenceException: Object reference not set to an instance of an object.

Source Error:

An unhandled exception was generated during the execution of the current web request.Information regarding the origin and using the exception stack trace below.

Stack Trace:

[NullReferenceException: Object reference not set to an instance of an object.]

     Microsoft.office.server.Administration.UserProfileApplicationProxy.get_ApplicationProperties()  +134

Microsoft.office.server.Administration.UserProfileApplicationProxy.get_PartitionIDs() +44

Microsoft.office.server.Administration.UserProfileApplicationProxy.IsAvailable(SPServiceContext ServiceContext) +134

Microsoft.office.server.WebControls.MyLinksRibbon.get_Portal Available() +44

Microsoft.office.server.WebControls.MyLinksRibbon.EnsureMySiteUrls() +60

Microsoft.office.server.WebControls.MyLinksRibbon.get_PortalMySiteUrlAvailable()+15

Microsoft.office.server.WebControls.MyLinksRibbon.OnLoad(EventArgs e) +91

System.Web.UI.Control.LoadRecursive()+65

System.Web.UI.Control.LoadRecursive()+190

System.Web.UI.Control.Page.ProcessRequestMail(Boolean includeStagesBeforeAsyncpoint, Boolean includeStagesAfterAsyncpoint) +2427

Solution:

If  you just doing Some POCs and got stuck with the above error mentioned problem.

Just do one thing

1. Go to Central Admin->Manage Service Application->delete the User Profile Service.

This will mak your site work and you can start Playing around.

Also if you want you User Profile to Start again, follow below link

https://myspexp.com/2011/04/28/user-profile-synchronization-servicehangs-on-starting-i-fixed-it/

This shell is a PowerShell instance with a collection of SharePoint-specific cmdlets (pronounced command-lets) installed. In this, we’ll take a look at the few of the main cmdlets.

First things first. Where can we find PowerShell?

When running on a SharePoint server, two possibilities exist: either select the SharePoint 2010 Management Shell from the Start menu.

 or

 open a command prompt and enter the following: "PowerShell". 

If we’re using the SharePoint management shell, the SharePoint snap-in will already be installed. If we’re using a standard PowerShell console, we can install the snap-in by entering the following command: "Add-PSSnapIn Microsoft.SharePoint.PowerShell"

We can check the list of installed snap-ins by using this command: "Get-PSSnapIn"

Some Basic Commands

1.Connecting to SharePoint Remotely

One of the real benefits of PowerShell is its ability to connect to remote machines. We can open a PowerShell session on a client machine and then use remoting to connect to a SharePoint server. To enable remoting on the server, entert he following command:

Enable-PSRemoting

This command will enable the WinRM service and set up the firewall to allow incoming sessions.

After the server has been configured, we can connect from any client machine by entering the following command:

Enter-PSSession "Server Name" -Credential
(Get-Credential)

NOTE: If the client machine is running on a domain and your SharePoint server is running as a standalone server, a few other steps are necessary to enable remote connectivity, such as configuring Secure Sockets Layer (SSL) connectivity on the server.

After a remote connection has been established, the SharePoint snap-in can be added with the command:

Add-PSSnapin Microsoft.SharePoint.PowerShell

2.PowerShell Permissions

To use SharePoint cmdlets, a user must be a member of the SharePoint_Shell_Access role for the farm configuration database as well as a member of the WSS_ADMIN_WPG group on the SharePoint front-end server. To grant users the appropriate permissions, use the following command:

Add-SPShellAdmin -Username domain\username -database
(Get-SPContentDatabase -> -webapplication)

Each user must be explicitly granted permissions to every database to which he or she needs access. By default, only the account used to sett up SharePoint will have permission to execute this command.

3.Working with Site Collections and Sites

Most of the cmdlets commonly used in the management of site collections or sites end in SPSite or SPWeb. To pick
up a reference to a site collection, we can use the following:

$site=Get-SPSite -Identity 

Or
we can return a list of all site collections by using this:

Get-SPSite

When it comes to managing site objects (SPWeb), we can pick up a specific web site using this:

$web=Get-SPWeb -Identity 

To return a list of sites, we need to use either the Site parameter or an SPSite object:

Get-SPWeb -Site

or

Get-SPWeb -Site $site

Creating Site Collections and Sites

We can create a new site collection using the New-SPSite cmdlet:

New-SPSite -Url https://localhost/Sites/NewSiteCollection- OwnerAlias username

We can also add new sites using the New-SPWeb cmdlet:

New-SPWeb -Url https://localhost/Sites/NewSiteCollection/NewWeb -Name MyNewWeb

Deleting Site Collections and Sites

We can delete site collections and sites by using the Remove-SPSite or the Remove-SPWeb cmdlet.

Remove-SPWeb -Identity https://localhost/Sites/NewSiteCollection/NewWeb

or

Remove-SPSite -Identity https://localhost/Sites/NewSiteCollection

Setting Properties on SharePoint Objects

When setting properties on the objects returned by SharePoint management cmdlets, we need to call the Update method in the same manner as when updating properties using the Server Object Model. Here’s an example:

$web=SP-GetSPWeb -Identity https://myweburl

$web.Title="My New Title"

$web.Update()

4.Working with Lists and Libraries

Similarly to how lists and libraries are accessed in the Server Object Model, they can be accessed via SPWeb objects. For example, we can enumerate the lists on a site using the following:

Get-SPWeb -Identity | Select -Expand lists| Select Title

We can add new lists using the Add method of the Lists property:

Get-SPWeb -Identity | ForEach {$_.Lists.Add("My Task List", "", $_.ListTemplates["Tasks"])} 

Changing the Business Connectivity Thresholds

The maximum number of rows that can be retrieved via a Business Connectivity Services (BCS) connection is limited. The only way to change this value is via PowerShell. We can use the following command to retrieve the current settings:

$proxies=Get-SPServiceApplicationProxy | Where {$_.TypeName -like "Business Data*"} $rule=Get-SPBusinessDataCatalogThrottleConfig -ServiceApplicationProxy $proxies -Scope -> Database -ThrottleType Items $rule

We can then update the value using the following:

Set-SPBusinessDataCatalogThrottleConfig -Identity $rule -Maximum 10000  Default 10000

5.Working with Content

We can retrieve a list of all items in a site using the following:

Get-SPWeb -Identity | Select -Expand Lists | Select -Expand Items |->select Name, Url

Or

we can apply a filter to show only documents:

Get-SPWeb -Identity | Select -Expand Lists | Where {$_.BaseType -eq -> "DocumentLibrary"} | Select -Expand Items | select Name, Url

We  can also make use of filters to search for a specific item:

Get-SPWeb -Identity https://myweburl | Select -Expand Lists | Select -Expand Items | -> Where {$_.Name -like "foo*"} | select Name, Url

Creating New Documents

To create a new document in a document library, use the following:

function New-SPFile($WebUrl, $ListName, $DocumentName,$Content)

{

$stream = new-object System.IO.MemoryStream

$writer = new-object System.IO.StreamWriter($stream)

$writer.Write($content)

$writer.Flush()

$list=(Get-SPWeb  $WebUrl).Lists.TryGetList($ListName)

$file=$list.RootFolder.Files.Add($DocumentName, $stream,$true)

$file.Update()

}

New-SPFile -WebUrl "" -ListName "Shared Documents" -DocumentName ->

"PowerShellDocument.txt" -Content "Document Content"

6.Working with Timer Jobs

SharePoint makes use of timer jobs to perform a lot of back-end processing. We can use PowerShell to get a list of all timer jobs:

Get-SPTimerJob

Or
we can get a list of job failures grouped by the job name:

Get-SPTimerJob | Select -Expand HistoryEntries | Where {$_.Status -ne "Succeeded"} -> | group JobDefinitionTitle

How to Create Feature stapler .

1.      First we need to create the Features (Staplee) which we want install on creation of site (publishing or team site etc.). How to Create feature. 

2.      Create a Feature Stapler as below

          <?xml version="1.0" encoding="utf-8" ?>

        <Feature xmlns="https://schemas.microsoft.com/sharepoint/" Id="C384D136-79A8-48BD-AF73-C630547F4D8E" Title="ExampleStapler" Description="This feature staples the 

           other feature to the Team Site definition." Scope="Farm" Hidden="False" Version="1.0.0.0" />  

3.    Create an element xml which is nothing but where feature association takes place.In order to add element.xml we need to create a module in Visual studio 2010 and then add the element.xml

    <?xml version="1.0" encoding="utf-8" ?>

    <Elements xmlns="https://schemas.microsoft.com/sharepoint/">

    <FeatureSiteTemplateAssociation Id="b8f334a0-1ffe-420d-b6e2-54a9faa6ba95" TemplateName="STS#0" />

    <FeatureSiteTemplateAssociation Id="07cb8bd4-7004-4021-8355-48d17de287e5" TemplateName="STS#0" />

    <FeatureSiteTemplateAssociation Id="90C924A7-32F7-4C19-BD4C-AF49EF0563A9" TemplateName="STS#0" />

    </Elements> 

The FeatureSiteTemplateAssociationID element maps feature(The Features which we want to install on creation of Site) GUIDs to site definitions.
Feature-stapling won't affect any sites which have already been created from a site definition, only subsequent sites. The only way to do this is to activate your features individually on the site.

So Once you deploy Feature Stapler to web application level and then you create a team Site the associated(Stappled)  features will get activated.

a.       The BLOB cache.

b.      The Page Output Cache.

c.       The Object Cache.

Page output and object cache require that you activate the ‘SharePoint Server Publishing’ feature located in the site features of your web site.

BLOB cache:

SharePoint Server 2010 provides a disk-based cache that stores files that are used by Web pages to help them load quickly in the browser, and reduces the load on the database server when it uses those files. The BLOB cache is stored directly on the hard disk drive of a front-end Web server computer. By default, the BLOB cache is off and must be enabled to use the functionality it provides. When you enable the BLOB cache on your front-end Web server, you reduce the load on the SharePoint Server 2010 database server created by read requests from Web browsers. You enable the BLOB cache in the Web.config file of the Web application to which you want to apply it. The changes that you make to the Web.config file will be applied to all site collections within the Web application. To configure and Setup BLOB Caching read here.

Page output cache profiles:

The second caching option you have with SharePoint 2010 is ASP.net Output Cache. This is an in-memory cache that saves rendered ASPX pages. Using Output cache improves performance in two ways first it reduces the amount of SQL calls. Second it reduces workload on the WFE because pages do not need to be re-rendered. Along those lines if the pages are anonymous, then no SQL check needs to be done at all present the cached pages. Microsoft testing concluded a ninefold improvement in throughput when compared to having to render the page every time it was rendered. To configure and Setup Output Caching read here.

 Object cache

Object cache is the third caching option we have for SharePoint 2010. What Object cache does is stores metadata about SharePoint Server objects (like SPWeb, SPSite, SPList, etc.) on the WFEs. When a page is rendered, if there is data that needs to be retrieved through these objects, the SQL Server will not be hit. Features of SharePoint that uses Object cache are publishing, content query web part, navigation, search query box and metadata navigation. These features are specifically written to use the Object cache API instead of the SharePoint API directly. Developers writing custom functionality can also tap into the Object cache API. To configure and Setup Output Caching read here.

BLOB Cache

1.       BLOB cache should be used when pages that are accessed frequently have JavaScript, CSS, images files, and large rich media files that can be cached on the WFEs

2.       It is recommended that you not set the cache size smaller than 10 GB for BLOB Caching. When you set the cache size, make sure to specify a number large enough to provide a buffer at least 20 precent bigger than the estimated size of the content that will be stored in the cache.

3.       For a publishing site for which most of the visitors are anonymous or where most of the files are static content, enable the BLOB cache for as many file types as possible.

4.       For other sites that contain lots of media assets that are read-only, or where only a small percentage of the media assets are updated, enable the BLOB cache for media files only.

5.       Make sure that you put the BLOB cache on a drive that has sufficient disk space available in front-end Web server which to store the cache.

6.       Select a drive that will be used by as few processes as possible so that the BLOB cache process does not encounter conflicts when it tries to access the drive

7.       If there is a high read to write ratio BLOB caching should be used. For instance you would want to cache a site logo that is used on every page request versus a collaboration word document that is actively updated.

8.       BLOB caching is optimized for supporting large files which can significantly reduce bandwidth between the WFEs and SQL Server.

9.       BLOB caching is optimized to support cache control headers so that clients can cache small files which can reduce overall number of hits to the WFEs.

10.   If there is anonymous access, there can be dramatic improvements because permissions do not have to be validated for cache files.

11.   Client applications that use range requests can optimize load times to access large files.

Before you enable the BLOB cache, carefully consider the scenario in which you plan to use it. If your site will be used for heavy collaboration, enabling the BLOB cache might temporarily affect the performance of your site while the files to be cached are first written to the disk. After the files have been stored in the cache, site performance will improve, so take this into consideration when you decide whether or not to enable the cache. Base your decision to enable BLOB caching on the following criteria:

·         For a publishing site for which most of the visitors are anonymous or where most of the files are static content, enable the BLOB cache for as many file types as possible.

·         For other sites that contain lots of media assets that are read-only, or where only a small percentage of the media assets are updated, enable the BLOB cache for media files only.

Page Output cache

1.       The only catch for using Output Cache is that it can only be used in conjunction with publishing pages. It cannot be used with a collaboration site.

2.       Some examples of rules that can be capture in a cache profile would be to not cache if the requestor is a user who can edit pages to ensure they see the latest version of content.

3.       The cache profile also specifies rules for when a page is invalidated so that when the next request is made, it comes from the database.

4.       One of the main considerations for Output cache is the memory needed to support it. For each rendered page, 2(size of the page) + 32KB is needed to store the rendered page in memory.

5.       Output Cache should not be used with sites using a low read to write ratio because frequent changes to content make it hard to keep the cache fresh.

6.       On multi-WFE, output caching may affect consistency.

 Object Caching

1.    The object cache cannot be disabled, and there is very little that can be configured. None of the out of box settings should have to be changed. Following article was written provides some additional information on this cache: Object Cache.

2.       They are normal ASP.net caching and can be a problem when Server data changes in case of multiple farm.

3.       It is recommended that you not set the cache size smaller than 3 MB.

Overall for caching we should keep in mind that any data where in Read/write ratio is less we should avoid caching. Only things which is static most of the time need to be cached like images etc.

When you flush the BLOB cache, you clear the contents of the BLOB cache for a Web application. This is useful if the BLOB cache becomes out of sync with the content. For example, after you restore a content database, the BLOB cache will be out of sync with the content. To correct that situation, you must flush the BLOB cache. The following procedure describes how to flush the BLOB cache for a Web application.

Important Information on Flushing:

a.       Flushing the BLOB cache for a Web application affects all site collections in the Web application.

b.      You cannot use the user interface to flush the BLOB cache. Instead, you use Windows PowerShell and the SharePoint object model to complete this task.

This is the link which tells you how to flush BLOB cache

SharePoint Designer 2010 is the premier tool to configure and customize SharePoint 2010. This document will help you to identify those situations where SPD can be helpful and identify situations where using SPD may be more of a hindrance than a help.

Before going through this Blog couple of things we need to keep in mind:

1.       Only SharePoint sites can be managed and customized in SharePoint Designer 2010.

2.       SharePoint Designer 2010 is not backwards compatible and cannot be used to open sites in SharePoint 2007 or earlier products.

If you are familiar about SharePoint Designer 2007 and new to SharePoint 2010,  I strongly recommend you to read through the following article

Discontinued features in SharePoint Designer 2010

https://office.microsoft.com/en-us/sharepoint-designer-help/discontinued-features-in-sharepoint-designer-2010-HA101782644.aspx

 Best Practices

1.       Do not “Customize” a Page based on a File in the

“14” Hive.

2.       Do not Install SPD on SharePoint Server

3.       Do not Develop a new Web Part when:

a.       It’s already provided Out of The Box

b.      The Data View Web Part can be used

4.       Do not Customize when

a.       SharePoint provides it Out of The Box

b.      Don't build a Master Page when a CSS theme will suffice the need.

5.       Do not edit the Out of The Box CSS files

6.       Do not start customizing from Production directly.

a.       We recommend the developer to develop the solution/customize the user interface in their own set up, then port the solution/customization to Kraft development server. After thorough testing, the same should be ported to staging and then Production (Cloud).

7.       Don’t delete files which are part of previous solution.  In case of any issues, developer should be in a position to roll back to previous solution.

8.       Do not modify any system or application pages like (files from 14 hive folder)

9.       Do not apply custom master page for system of application pages. While we change the master page, we have two options, site master page and system master page (for example /_layouts/settings.aspx, /_layouts/viewlsts.aspx) . Not to change the system master page. 

10.   Avoid customizing pages which are frequently accessed and requires less page load time.

11.   Make sure you have a way back.

12.   If edit Existing Page

a.       Create a Copy

b.      Make your Amendments to your Copy

c.       Make your Copy Active

13.    Remember Web Part Properties in Web Part Zones are not versioned.

14.   Enable versioning for the artifacts which are getting customized.  In case of any issues, this will help rolling back to previous version.

    Workflow

Reusable workflows

With SharePoint Designer 2010, you can create workflows that are easily reusable. You can create a reusable workflow in the top-level site in the site collection, and that workflow is globally reusable — meaning that the workflow can be associated to any list or library in the site collection. You can also create a reusable workflow in any sub site in the site collection; this workflow is available for reuse in that particular sub site.

 Packaging

A unified packaging system makes it a lot simpler to export an application and import it elsewhere. In SharePoint Designer 2007, there was a packaging schism between .stp site templates and .wsp files. When should one choose one over the other, and why have to choose in the first place? In 2010, this schism was healed .wsp is now the one way to go.

  Import and Export artifacts

a)      Now you can export a reusable workflow from one site collection and then upload and activate that workflow in a different site collection. SharePoint Designer 2010 supports exporting a workflow as a solution package or .wsp file.

b)      Saving a site as a template is a powerful feature because it offers so many different uses of custom sites in SharePoint. Here are the immediate benefits you get from saving a site as a template in SharePoint.

c)       Customized SharePoint sites can be deployed as solutions immediately Save and activate the template in the solutions gallery and let other employees create new sites from this template. You don’t need Visual Studio to create your solution, and you have to access the server directly and run server administrator commands. Just save the site as a template, activate it, and off you go.

d)      Customized SharePoint sites are portable – In addition to deploying a custom solution in your environment, you can download the .wsp file, take it on the road, and deploy it in another SharePoint environment. All of your site customization is conveniently stored in one file.

e)      Customized SharePoint sites are extensible – As a Web Solution Package, you can open your customized site in Visual Studio, perform additional development customization to the template and then deploy it to SharePoint. SharePoint site development, as a result, can go through a site development lifecycle that includes SharePoint Designer 2010, Microsoft Visual Studio, and the browser.

The following table provides a quick summary of what’s in out of a typical site template which you can Export.                  

Once you’ve saved your site as a template, a solution file (.wsp) is created and stored in the Solution Gallery for the site collection. From here, you can download or activate the solution.

With your solution uploaded and activated in the Solution Gallery, users will see it as an available template on the Create site page in SharePoint. You can select it and create a new site from it, which will inherit the components of the site, its structure, workflows, etc. Also can download your solution from the Solution Gallery and deploy it in another SharePoint environment.

 Recommendation

1.       Do not allow end users (non-technical) to use SharePoint Designer

2.       Reusable workflows should be exported to Visual studio and then do the enhancements

3.       Master page customizations done in SharePoint designer should export to Visual studio and a common WSP should be created.

4.       Apply required security settings. Below section explains how to control the SharePoint Designer from Server side.

Manage SharePoint Designer 2010

To manage how SharePoint Designer 2010 is used in your organization, you can use one of two SharePoint Designer Settings pages:

·         Central Administration > SharePoint Designer Settings

·         Site Collection Administration > SharePoint Designer Settings

Both pages can be used to enable or disable SharePoint Designer and its capabilities for detaching pages, editing master pages and page layouts, and editing files in the web site URL structure. The main difference is that in Central Administration, the settings apply to site collection administrators at the web application level – and on the site collection administration page, they apply to designers and owners at the site collection level.

Central Administration

Use the SharePoint Designer Settings page in Central Administration to manage SharePoint Designer at the web application level, which includes all site collections in the web application. These settings apply to site collection administrators and all users of the web application.

Site Collection Administration

Use the SharePoint Designer settings on the Site Collection Administration page to manage SharePoint Designer at the site collection level, which includes all sites in the collection. The settings apply to all site owners and designers, but not site collection administrators.

Note In SharePoint, only the Designers group and above can open SharePoint sites in SharePoint Designer 2010. As such, all other groups, like Contributors and Readers, aren’t affected by these settings.