Using a highly available Microsoft SQL Server database for ArcGIS service data can avoid downtime for your web services.
SQL Server provides several high-availability solutions. ArcGIS supports connections to AlwaysOn Availability Groups and Failover Cluster Instances.
A Failover Cluster Instance provides a redundant SQL Server instance to which clients can connect if one instance fails. Availability Groups allow you to specify a set of primary databases and up to four sets of read-only secondary databases spread over Failover Cluster Instances.
Note:
Read the SQL Server AlwaysOn help in the Microsoft documentation before implementing this solution.
After you have an AlwaysOn solution in place, you can connect to it from ArcGIS by specifying the availability group listener name instead of the SQL Server instance name. Append additional conditions to the group listener using the Additional Properties settings on the Database Connection dialog box, or append them to the instance string by separating the group listener name and each parameter with a semicolon (;).
You can add the following conditions in the instance string or as properties and values under Additional Properties on the Database Connection dialog box:
- APPLICATIONINTENT=READONLY or APPLICATIONINTENT=READWRITE
Note:
The READONLY value is only supported if you connect to an AlwaysOn Availability Group listener.
- MULTISUBNETFAILOVER=YES or MULTISUBNETFAILOVER=NO
If you do not specify values for the APPLICATIONINTENT and MULTISUBNETFAILOVER settings, the default values are READWRITE and NO, respectively.