Starting from versions 7.4.17.78, the system supports partial updates. Unfortunately, not all adjustments are adequately processed by older versions, so report and reference servers switch to the lower versions compatibility mode if at least one client connected to them has a lower version than the one suitable for a given adjustment. For example, currently, such adjustments are:

• Expanding the number of rights in the system (the information in Russian)
• Increasing the maximum number of report servers (the information in Russian)

Let us investigate the system functioning in the context of these adjustments, using the below diagram as an example. Servers connected to the reference server have the version that can handle these adjustments correctly. Consequently, the reference server does not switch to the compatibility mode, and all the work is done in full. The situation is similar with the servers on the left side of the diagram, as their versions (21) fully support the introduced adjustments. But the server on the right side of the diagram switches to the compatibility mode because it is connected to servers of various versions, including those that do not support the above-mentioned adjustments. This makes the server on the right send abridged datasets to servers below. Therefore, the following capabilities will be missing in the server chain depicted on the right side of the diagram:

• Using an extended set of rights (only 255 rights will be available in the order of their creation in the system)
• Using more than 254 report servers (only 254 servers will be available in the order of their creation in the system)

Thus, the upgrading process (necessary in case of using adjustments switching into the compatibility mode) becomes iterative: you should gradually upgrade server chains by connecting them to newer versions of report servers.