Multi-Site Requirements

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.

High Availability

  • For XenMobile cluster nodes, Citrix ADC handles the load balancing. For more information, see Configure Clustering
  • 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 Citrix ADC instances wherever possible to allow the configurations to sync with a second Citrix ADC.
  • The standard Citrix ADC high availability pair operates in an active/passive configuration.

A typical high availability XenMobile deployment typically includes:

  • Two Citrix ADC instances (VPX or MPX). If the Citrix ADC SDX platform is used, high availability should also be considered.
  • Two or more XenMobile servers configured with the same database settings.

Disaster Recovery

You can configure XenMobile for disaster recovery across two data centers with one active data center and one passive data center. Citrix ADC 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 Citrix ADC 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 Citrix Gateway URL handling traffic to the site.
  • When you use the Citrix ADC for XenMobile wizard to configure Citrix Gateway, by default, the GSLB is not enabled to resolve traffic to the XenMobile enrollment server and traffic to the Citrix 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.

Note:

The disaster recovery methods described in this handbook provide only automated disaster recovery for the access layer. You must manually start all XenMobile server nodes and the SQL Server database at the failover site before devices can connect the XenMobile server.

Multi-Site Requirements