PrizmDoc® Viewer v13.26 Release - Updated
PrizmDoc Viewer / Administrator Guide / PrizmDoc Server / Installing / Install on Windows / Registry Changes
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    Registry Changes
    In This Topic


    The PrizmDoc installer will modify the registry to increase the size of the non-interactive heap, allowing the Prizm service to create more than the default number of child processes to run its micro-services.

    If the registry already contains a value greater than necessary, no changes to the registry will be made. If the registry is modified, and PrizmDoc is un-installed, the original registry values will be replaced.

    NOTE: Upon start up, the PrizmDoc Server checks whether or not the system's non-interactive heap size corresponds to the CPU cores count, and in the case of a discrepancy, the Admin page will never show a 'Running' status, and the OfficeConversionService.log will contain the error message: "Non-interactive heap size does not correspond to CPU cores count, going to 'Unhealthy' state". Please follow the recommendations provided in the next two sections below to avoid server configuration errors related to a mismatch between the non-interactive heap size and the CPU cores count.

    Interactive Installation

    A manual heap size value adjustment process is not required when the PrizmDoc Windows Server installer is running in its interactive UI mode, where it will make all of the necessary registry changes and require a system reboot.

    Please make sure to install the product on the system, with the final CPU cores count to be used in production, so that the product installer will adjust the non-interactive heap size accordingly, corresponding to the actual CPU cores count.

    Due to a known issue with the installer, it might not ask for a reboot after the installation, so please make sure to reboot the system manually. This issue will be addressed in the future release.

    Non-Interactive Installation

    In order to avoid a system reboot when installing PrizmDoc Server for Windows in non-interactive mode, such as for cloud-based systems using auto-deployment, the cloud image must have its registry modified as described below.

    Registry Changes

    Registry Key: HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Session Manager\SubSystems

    Value: Windows

    The value is a complex, space separated set of system wide settings, one of which is named "SharedSection". This is a comma-separated string value containing 3 numeric values that may look like: SharedSection=1024,20480,768.

    The third numeric value is a non-interactive desktop heap size in kilobytes, which must be set to the Heap Size Value (see table below) corresponding to the number of CPU cores in the server:

    CPU Cores Instance Count Heap Size
    Multiplication Factor
    Heap Size Value
    1 1 1 768 (default)
    2, 3 Number of Cores 2 1536
    4 <= Cores < 8 4 2 1536
    8 8 3 2304
    12 12 4 3072
    16 16 5 3840
    20 20 6 4608
    24 24 7 5376
    28 28 8 6144
    32 32 9 6912

    The heap size value is calculated from the default size by applying a heap size multiplier corresponding to the number of CPU cores available on the server.

    The instance count indicates the number of concurrent Office document converter processes the Office Conversion Service will handle when using the MSO option. The total number of running Office document converter processes will be twice the number of concurrent instances - this is done in order to improve the performance of the Office Conversion Service.

    NOTE: The PrizmDoc Server limits the max CPU core usage to 32 for Office documents processing. If your machine has more CPU cores, the extra ones will not be utilized to avoid server's overload and instability - this is related to the system resources usage by MSO. So if you need to utilize more CPU power for Office documents viewing and conversion, please consider using PrizmDoc Server Clustering.