Local Host Cache (LHC), which was a key feature of the IMA architecture in XenApp 6.5 and earlier was reintroduced for the first time in the FMA based XenApp/XenDesktop 7.12 release. You can learn more about LHC in detail in my previous blog on the topic.
Prior to 7.12, users were able to access resources (with some caveats) while experiencing site database loss using a feature known as Connection Leasing. When upgrading to 7.12 from an earlier release with Connection Leasing enabled, LHC is disabled by default.
To enable LHC run the following powershell command on the upgraded broker.
Set-BrokerSite -LocalHostCacheEnabled $true -ConnectionLeasingEnabled $false
The above command, enables Local Host Cache and disables Connection Leasing.
The Get-Brokersite cmdlet provides the current state of Local Host Cache (whether its enabled or disabled)
To disable Local Host Cache and enable Connection Leasing, run the following command:
Set-BrokerSite -LocalHostCacheEnabled $false -ConnectionLeasingEnabled $true