You can architect and configure XenMobile deployments that include multiple sites for high availability and disaster recovery. This article provides an overview of the high availability and disaster recovered models used in XenMobile deployments.
- For XenMobile cluster nodes, NetScaler handles the load balancing.
- XenMobile server nodes operate in an active/active configuration.
- Additional XenMobile server nodes are added to a high availability cluster as capacity is required. One node can handle up to approximately 8,500 user devices (see Scalability and performance for additional detail).
- Citrix recommends configuring "n+1" XenMobile servers: one server for every 8,500 user devices and one extra server for redundancy.
- Citrix recommends high availability for all NetScaler instances wherever possible to allow the configurations to sync with a second NetScaler.
- The standard NetScaler high availability pair operates in an active/passive configuration.
A typical high availability XenMobile deployment typically includes:
- Two NetScaler instances (VPX or MPX). If the NetScaler SDX platform is used, high availability should also be considered.
- Two or more XenMobile servers configured with the same database settings.
You can configure XenMobile for disaster recovery across two data centers with one active data center and one passive data center. NetScaler and Global Server Load Balancing (GSLB) are used to create an active/active data path so that the user experience is that of an active/active setup.
For disaster recovery, a XenMobile deployment includes:
- Two data centers; each contains one or more NetScaler instances, XenMobile servers, and SQL Server databases.
- A GSLB server to direct traffic to the data centers. The GSLB server is configured for both the XenMobile enrollment URL and NetScaler Gateway URL handling traffic to the site.
- When you use the NetScaler for XenMobile wizard to configure NetScaler Gateway, by default, the GSLB is not enabled to resolve traffic to the XenMobile enrollment server and traffic to the NetScaler Gateway, en route to the MAM load-balancing server; as a result, additional steps are required. For more information on preparing for and implementing these steps, see Disaster Recovery.
- Clustered SQL Servers of Always On Availability Groups.
- Latency between the XenMobile servers and SQL Server must be less than 5 ms.