Primary and multiple backup systems configuration example

This example illustrates a distributed project’s configuration, that gives system control of multiple backup systems to a primary system during night shift. In this example, the I/O points within the remotes are divided into datasets that are geographically aligned.

The figure below displays the dynamics between a primary and its backup systems and remotes. Configuration requires that the primary is able to assume full control of the backup systems during night shift.

During the day shift, the Backup 1 and Backup 2 systems assume most of the control. In this example, both datasets can be controlled by either Backup 1 or 2, with the exception of the central dataset. Due to the nature of the system, there is no need for redundant system control of the central dataset.

The table below explains the above configuration’s system roles throughout the day:

The table below outlines the requirements for configuration of a primary system with multiple backup systems, with specific reference to the example above. This example requires the following configuration specific to distributed projects:

• PRIBAC1 connects the primary system PRI to BAC1.

• PRIBAC2 connects PRI to BAC2.

  Note: Though it is possible you may want to configure your backup systems to interact with each other, in this example, no connectivity was configured between BAC1 and BAC2

  Requirements for Primary and Multiple Backup Systems Configuration

  Table	Description
  doas_dataset	The data points are grouped into three regions; therefore, three doas_dataset records are required: Central East West
  doas_mode	In this example, the modes are configured and named to correspond to the shifts that the Controllers use: AM for weekday shifts PM for nights and weekend shifts NOTE: In these cases, the mode groups are named after the datasets because it happens to fit the use of the distributed project. It is not a requirement. Five doas_mode records are required for this configuration: centralALL will give PRI ownership of the central dataset. eastAM will give BAC2 ownership of the east dataset. eastPM will give PRI ownership of the east dataset. westAM will give BAC1 ownership of the west dataset. westPM will give PRI ownership of the west dataset.
  doas_privilege	The maximum of 45 privilege records can be used for this example. This figure is calculated by multiplying the number of systems (3), by the number of datasets (3), by the number of modes (5). Most of these records would be set to the default privilege, which states that a system has no privileges over a dataset in a given mode. Hence, these records are not required for this example because the rest of the records will state the default privilege. The doas_privilege records are defined in the next table. Similarly, using a spreadsheet will help you manage the privileges specific to your system.

The textual information on datasets, modes, and systems have been aligned with privileges in the table below. It helps explain the systems in the primary with multiple backup systems example. For any given system, you would need to:

• Follow the column down to and insert the name of a mode for the corresponding dataset and privilege

• Decide whether or not the mode you have created will possess the corresponding privilege over the dataset

  Privilege	Dataset	PRI System	BAC1 System	BAC2 System
  Ownership	Central West East	centralALL westPM eastPM	westAM	eastAM
  Control	Central West East	centralALL westPM eastPM	westAM	eastAM
  Configure	Central West East	centralALL	westAM westPM	eastAM eastPM
  Alarm	Central West East	centralALL westAM westPM eastAM eastPM	westAM	eastAM
  Event	Central West East	centralALL westPM eastPM	westAM westPM	eastAM eastPM
  Accumulate statistics	Central West East	centralALL westPM eastPM	westAM	eastAM
  Historical collection	Central West East	centralALL westPM eastPM	westAM	eastAM

Follow the column of a system and note each unique mode that appears in the column. The number of unique modes in all columns is equal to the minimum number of privilege records that must be created.

As shown in the above table, the number of doas_privilege records required here is 9, which corresponds to the number of noted modes: 5 under the PRI column, 2 under the BAC1 column, and 2 under the BAC2 column.

Create 9 blocks of cells showing the default privileges like the ones shown in the table below. These will become the privilege records.

Note: For each of the 9 records, provide the 9 unique combinations of dataset, system, and mode names that correspond to the 9 unique modes.