In the establishment of two active / active Data Centers, a new solution is available since version XenApp / XenDesktop 7.7. This new release includes a new « Zone » functionality. You have to understand how this new functionality works so as to understand its limits.
Usually, in our two active / active Data Centers architectures we want the user to be redirected to the closest Data Center to his location. We propose to you today a comparison in Site versus Zone mode.
In Site mode
A site is created on each Data Center. The configuration must be duplicated on each Data Center. It is important to have the exact same name for each application. The Storefront from each site should not be paired. The addition of an AD group in the configuration of the Storefront enables the determination of the primary and the secondary site from each site. Those AD will redirect the user to the Data Center assigned by the administrator.
- The user is redirected to the assigned Data Center
- Easier management of personal files
- Much stronger in case of corrupted Database on one of the sites
- Configuration has to be done on each site
In Zone mode
One site is created with two zones for each geographic site. Each site must have an hypervisor, a machine catalog and a separated controller. The machine catalogs from each zone are linked by the distribution group. With the help of the Netscaler, the user is redirected to the Storefront or the closest Gateway. The redirection of the connections is based on different modes offered by the Netscaler like the « Static Proximity » or the « Dynamic Proximity ». The application is open on the distribution group that contains both machine catalogs. Given that the zone information is not send to the controller, the user can open a session randomly on both zones. Note that it’s not yet possible to redirect a user to the closest zone.
- Applications management is centralized on one site
- Impossible to assign a zone based on an AD group
- Currently impossible to open a session on the closest site
- The management of personal files is more difficult, they have to always be available on both sites
Currently the only way to redirect the user to the closest site is still the site mode. The zone mode will be reassessed when the zone information can be transferred to the controller. In this case, the user will be dynamically redirected on the closest site. Given that the user can move around, it is likely that the session doesn’t always open on the same site, thus you should take into account the availability of the profile and personal data. To conclude, the data management is easier in site mode due to better control of the user’s site.