Cluster Configuration Storage Options
Microsoft AppFabric 1.1 for Windows Server allows the option of storing your cache cluster configuration settings in a shared folder, in a SQL Server database, or in a custom configuration store. This topic describes considerations for choosing among these options.
When you select the shared folder-based cluster configuration storage option, you must provide a shared network folder in which to store the configuration data. When you select the SQL Server-based option, you must provide a SQL Server database. A custom configuration storage option is available only if you have installed a custom provider on the server that supports this option.
Note
The cluster configuration storage location should not be located on any of the cache servers. It should be on a computer in the same domain as the cache servers, primary data source server, and cache clients—all within the perimeter of the firewall.
Editing Configuration Settings
Choices for editing the cluster configuration settings are not determined by how you store the configuration settings. You can edit configuration settings with Windows PowerShell or by using the Windows PowerShell Export-CacheClusterConfig and Import-CacheClusterConfig commands to edit configuration settings directly with XML. For more information, see Configuring the Cache Cluster.
Selecting Configuration Storage Options
When you decide which storage option to use for cluster configuration settings, there are three primary factors involved in the decision:
Cluster management options. Do you want SQL Server or lead hosts to perform the cluster management role?
High-availability resources. What highly available resources do you have at your disposal? For example, does your organization already have a "clustered" SQL Server resource available for your distributed cache system to use?
Cluster size. Do you want a large cluster? Large clusters may have contention issues when using shared network folders to host the configuration settings. Some operating systems support only a limited number of concurrent connections.
Cluster Management Options
There are different options for how the cluster management role is performed, depending on how you deploy your distributed cache system. For more information, see Lead Hosts and Cluster Management (AppFabric 1.1 Caching).
If you store your cluster configuration settings in a SQL Server database, that SQL Server instance can also be used to perform the cluster management role. If you choose to store your cluster configuration settings in a shared folder, the cluster management role is always performed by special cache hosts, referred to as lead hosts. This is illustrated in the following table:
| Cluster configuration storage type | Cluster configuration storage location | Cluster management |
|---|---|---|
XML file |
shared network folder |
lead hosts |
SQL Server database |
SQL Server |
SQL Server (default) or lead hosts |
Custom |
custom store |
custom provider |
High-Availability Resources
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 Windows Server 2008 Failover Clustering (https://go.microsoft.com/fwlink/?LinkId=130692) when you can, to optimize the availability of your cluster's configuration data. Consider which "clustered" resources are available to your application (in your environment) and balance that with the degree of availability required for your distributed cache system to decide which storage option is best for you.
For example, your infrastructure may already have a "clustered" SQL Server database available to store your configuration settings. Alternatively, there may be a "clustered" folder available for you to deploy a shared folder-based cluster configuration.
Cluster Size
When using a shared folder to store your cluster configuration settings, the operating system that is used for the cache configuration storage location may limit the number of concurrent connections to the shared folder. In such cases, it is not supported to have the number of cache hosts in the cluster exceed that limit.
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.
When you use a SQL Server database to store cluster configuration settings, a shared network folder is not required. With SQL Server, there are not the same limits on concurrent connections as there are for shared folders. Instead, a maximum number of concurrent connections to the instance of SQL Server can be imposed by the database administrator. In SQL Server, the maximum number of concurrent connections is configured at the server level. The server may be configured not to have any limits on concurrent connections, or the database administrator may configure that setting very low for administrative or other reasons.
When using a SQL Server database to store cluster configuration data, make sure that the instance of SQL Server can accommodate additional connections before you add cache hosts to the cache cluster.
In This Section
See Also
Concepts
Cluster Configuration Settings
Lead Hosts and Cluster Management (AppFabric 1.1 Caching)
Configuring the Cache Cluster
2012-09-12