Disable/enable the Distributed cache service

Question

After experiencing a enormous slow Sharepoint installation with a minimum of active users I decided to stop the Distributed cache service. This turned SP in a fast and smooth application.

This resulted in a few errors and warnings in the Admin site:

• Warning | This Distributed Cache host may cause cache reliability problems.
• Error | Distributed cache service is not enabled in this deployment.

What are the pro's/con's of deactivating this service? And how do I keep Sharepoint fast and smooth if this service is turned on?

Answer 1

I wouldn't stop this service. SharePoint use it in several ways:

• User profiles Updates go to cache; all servers then see this update.
• User authentication No more multiple logons when moving across Web Servers. All logon tokens are cached and reused across the farm.
• App authentication Caches Open Authorization (OAuth) tokens and prevents a need to return to ACS.
• Newsfeeds Caches the newsfeed items on team and My Sites.
• Security trimming Caches the security of newsfeed and profile activities.
• View state Saves MDS viewstate. Search query Web Part Caches search results.

If you want to improve the speed of your server you may allocate less memory to the DCS using the Windows PowerShell Update-SPDistributedCacheSize cmdlet with the CachceSizeInMB parameter.

If you stop all instances, you will see several features (such as newsfeeds) of SharePoint 2013 stop working.

Answer 2

As many item types are stored in the distributed cache (e.g. tags, document activities, authentication and security information etc.) it is not recommended that the distributed cache is disabled.

Many of the objects that end up in the distributed cache are computationally expensive, time-intensive to fetch, or a combination of the two. Storing these items in memory spread across a number of servers in the farm eases the pressure on the farm to return these items and allows operations to proceed more quickly.

Having said that, the default configuration option for the distributed cache on the farm is to have it running on all servers, a situation that Microsoft recommends against as this can also cause issues. This does however depend on the number of servers in the farm. If you have only a couple of servers in the farm (e.g. two servers that are acting as combined WFE and APP servers), then the cache service should run on both of those, if you have greater number of servers (e.g. two WFE servers, two APP servers), then consider running the cache on only two of those servers (generally the two WFE servers). Try to avoid running other services on the same servers as the distributed cache, specifically Search Services, Excel Services and Project Server Services.

The recommended approach is to use dedicated cache servers and allocate most of the RAM on the server to the cache service. For what would have been a four server 2010 farm (2x WFE, 2x APP), this ends up being a recommendation for a six server farm in 2013 (2x WFE, 2x APP and 2x distributed cache).

Also check the SharePoint logs for mentions of the distributed cache as anything that is causing issues should show up in the logs (e.g. permission errors, access issues etc.).

Andy