Repair a Distributed cache host

 

During installation, configuration, or maintenance activities, the Distributed Cache service might enter a non-functioning state. Evidence of a malfunctioning Distributed Cache service will appear in Health Rules in Central Administration, or when users use features in SharePoint Server 2013 that rely on the Distributed Cache.

For example, the Newsfeed on a user's My Site will start reporting errors. Also, administrators might receive the error message "cacheHostInfo is null " when they run Windows PowerShell cmdlets to manage the Distributed Cache service.

Use the following procedure to restore a non-functioning Distributed Cache host.

1. At the Windows PowerShell command prompt, run the Get-SPServiceInstance cmdlet to list all services on all servers in the server farm. Make note of the GUID in the ID property of the Distributed Cache service on the server that you are repairing. The Get-SPServiceInstance cmdlet lists all services on all servers in the server farm. Ensure that you note the correct GUID from the server that you are repairing.

2. At the Windows PowerShell command prompt, run the following command:

3.  $s = Get-SPServiceInstance GUID

4.  $s.delete()

Where GUID is the GUID of the Distributed Cache service noted in step 1.

5. At the Windows PowerShell command prompt, run Add-SPDistributedCacheServiceInstance to reinstall and start the Distributed Cache service on the cache host that you are repairing.

Technorati Tags: Distributed Cache Service,SharePoint 2013

The number of Distributed Cache hosts in the farm exceeds the recommended value

 

When you open Central Administration in SharePoint 2013, you see the following error message

http://technet.microsoft.com/en-us/library/jj891124.aspx

The Distributed Cache service (by default) is started on every server in a farm.

On a farm with four or more servers, you must not start the Distributed Cache Service on all servers in the farm. If you configure all servers as cache hosts, you may experience reliability and performance problems in the farm.

Resolution: Reduce the number of cache hosts by using Windows PowerShell.

1. Verify that you have the following memberships:
   • securityadmin fixed server role on the SQL Server instance.
   • db_owner fixed database role on all databases that are to be updated.
   • Administrators group on the server on which you are running the Windows PowerShell cmdlets.
   • Farm Administrators group.

An administrator can use the Add-SPShellAdmin cmdlet to grant permissions to use SharePoint 2013 cmdlets.

2. Start the SharePoint 2013 Management Shell.
   • For Windows Server 2008 R2:
     • On the Start menu, click All Programs, click Microsoft SharePoint 2013 Products, and then click SharePoint 2013 Management Shell.
   • For Windows Server 2012:

On the Start screen, click SharePoint 2013 Management Shell.

If SharePoint 2013 Management Shell is not on the Start screen:

Right-click Computer, click All apps, and then click SharePoint 2013 Management Shell.

For more information about how to interact with Windows Server 2012, see Common Management Tasks and Navigation in Windows Server 2012.

3. Remove one or more servers from the cache cluster. On each server that you want to remove from the cache cluster, run the following cmdlet:

Remove-SPDistributedCacheServiceInstance

4. Verify that the server is removed from the cache cluster. To do this, in the SharePoint Central Administration website, click Manage services on server, and then, on the Services on Server page, make sure that the Distributed Cache service is not listed for the server from which you removed the service.

 

 

Technorati Tags: SharePoint 2013,Distributed Cache Service,SharePoint health Analyzer,Central Administration