If your users are running your application as a virtualized application, chances are high they use VMWare vSphere (Hypervisor ESXi) and are using snapshots.

4D v16 R2 will automatically install a VSS writer service. VSS stands here for Volume Shadow Copy Service. When the VMWare administrator starts a snapshot, VMWare informs the guest, which informs the VSS writer, which will inform 4D Server to flush the cache and wait for one second. Then it will inform the OS that the .4DD, .4DIndx and .Journal files belong together and must be snapshot at the same time. The OS will handle this and 4D Server can continue to handle client requests. The “freeze” lasts around a second, usually not even noticed by connected users.

The 4D Server Windows 64-bit administration window has been modified so you can check at anytime whether the VSS writer service is running correctly:

Example

This video shows the creation and restoration of a VMwareESXi snapshot while a 4D application is running on 4D Server. Take a look at it to know more about using Volume Shadow copy Service!

The brand new Microsoft Windows Server 2016 is including a new feature named “production checkpoint” and we are proud to announce that 4D v16 R2 is fully ready to support this technology!

Of course, more details can be found in the 4D Server v16 R2 documentation.