Shared Folder-Based Cluster Configuration

Microsoft AppFabric 1.1 for Windows Server provides the option of storing cache cluster settings to a shared folder that you designate. Within that folder, AppFabric creates an XML file to store the cluster configuration settings. This file is created automatically when configuring AppFabric Caching features with the AppFabric Configuration Wizard. AppFabric uses this configuration file as the primary point of reference for defining the cache cluster, cache hosts, and named caches.

For more information about preparing a shared folder for the cluster configuration storage location, see Windows Server AppFabric Installation Guide (https://go.microsoft.com/fwlink/?LinkId=169172).

Before configuring Caching Services on the first cache server, you must create and configure a shared folder to act as the cluster configuration storage location. This must be a shared network folder rather than a local path on any of the cache hosts. The installation program will need this shared folder to create or modify the cluster configuration files and folder structure. For this reason, all cache servers in the cluster must be able to access the cluster configuration shared folder.

The cluster configuration storage location can be a single point of failure for your distributed cache system. For this reason, we recommend that you use Microsoft Windows Server 2008 Failover Clustering (https://go.microsoft.com/fwlink/?LinkId=130692) to host a "clustered" folder resource for the cache cluster configuration storage location. Doing this will provide high availability for your cluster's configuration data.

Important

The shared folder that contains the cluster configuration settings is accessed specifically for the following operations:

  • When starting the cache host Windows service on any cache server in the cache cluster.

  • When a cache host is added to or removed from a cache cluster.

  • When a named cache is added to or removed from a cache host in the cache cluster.

If none of these operations are taking place then the cache cluster will continue to operate normally even if the shared folder that contains the cluster configuration settings is temporarily unavailable, such as during a Windows Server cluster failover of a clustered folder resource used for the cache cluster configuration storage location.

Note

Windows XP, Windows Server 2003, and the 32-bit version of Windows Vista do not allow more than 10 concurrent connections to a shared network folder. We do not recommend that you use these operating systems to store the cache configuration settings for large clusters.

Permissions

The cluster configuration shared folder must have its sharing and security settings configured so that each cache server has read and write permission to the folder contents.

Note

The AppFabric Configuration Wizard attempts to configure these permissions automatically. Note that the security identity of the user performing the installation must have owner permissions on the shared folder. In addition, the user performing the installation must satisfy one of the following two conditions:

  • The user is a member of at least one of these user groups on the machine where network share is located: Administrator, Power User, Print Operator, or Server Operator.

  • Or the user must be locally logged on to the machine where the network share is located.

To simplify long-term administration of the cluster configuration folder, do not run the cache service under the credentials of a domain user account. By using the default installation settings, you can use the domain computer accounts of the cache servers instead and avoid password maintenance.

If you create a Windows security group to manage access to the cache configuration shared folder, you set up permissions on that folder only once. For example, if the Windows security group is named ClusterACacheServers, it indicates that the cache servers have permission to become part of the cache cluster named ClusterA.

After you create the ClusterACacheServers security group, grant the domain computer accounts of the applicable cache servers membership to this group (for example, "domain\computername$"). Then grant ClusterACacheServers read and write permissions in the sharing and security settings of the cluster configuration shared folder. When this is set up, for each new server that you add to the cache cluster, add only the domain computer account of the new server to the security group.

See Also

Concepts

SQL Server-Based Cluster Configuration
Cluster Configuration Settings
Configuring a Cache Client
Configuring the Cache Cluster
Developing a Cache Client

  2012-09-12