Data Mirroring

Historian provides mirroring of stored data on multiple nodes to provide high levels of data reliability. Data Mirroring also involves the simultaneous action of every insert, update and delete operations that occurs on any node. Data mirroring provides continuous data read and write functionality. The Enterprise Edition of Historian allows you to have up to 3 mirrors: a primary and two additional mirrors.

In a typical data mirroring scenario, one server acts as a primary server to which the clients connect. To create a mirror, you add mirror nodes and establish a data mirroring session relationship between the server instances. All communication goes through the Client Manager, and each Client Manager knows about the others. Mirrors must be set up in a single domain. You can add only 3 nodes in a mirrored environment.

Note: The topic of mirroring is covered in depth in the GE Historian Getting Started Guide.

Requirements for configuring Mirror Nodes

The hardware and software requirements for all the nodes should be identical. For more information on the Hardware and Software requirements, refer to the Getting Started Guide. Mirrors must be set up in a single domain.

The minimum requirements needed for configuring the Mirror Nodes are:
  • Minimum 8GB RAM
  • Dual Core Processor
  • 64-Bit Operating System
If a Primary Node fails, you will not be able to view:
  • Tag Properties
  • Tag Aliases
  • Collectors
  • Collector Properties
  • Enumerated Sets
  • Enumerated Set Properties
  • Data Stores
  • Tags of User Defined Types
  • User Defined Type Tag Properties
  • Services Properties

Mirror Node Setup

The following diagram helps you to understand a typical single mirror node setup.