Concepts

Data replication is a basic concept that can be applied in many ways to deliver a wide variety of solutions for availability and scalability. FairCom replication is specifically designed to create available and scalable solutions. It provides a browser-based management utility making it quick and easy to construct a cluster architecture that meets your precise needs. This section describes the core components of replication, including publications, subscriptions, and plans.

The Replication Manager uses the concepts of publications and "subscriptions" to manage the replication of files. The idea is based on a magazine subscription. When you publish a magazine, you make it available to anyone who wants to subscribe to it. The subscribers will not be able to see the magazine until the publisher (owner) publishes it and the subscriber subscribes to it.

Figure 1. Replication server

The source publishes the files to be replicated. The target subscribes to the publication.

In this way, the owners can control which magazines are made available for the public and the subscribers can control which items they want to view. When you set up the replication agent, you decide which server will be the source of replication and which server will be the target, which is the destination of the replicated data.

Example 1. Publish and subscribe

Note

This example uses the simplest case as a way of explaining the terminology. Notice that the replication agent allows more sophisticated replication, such as bi-directional replication in which each server acts as both source and target. Because the capabilities of the replication agent extend beyond the simple example of magazine subscriptions, we will limit this explanation to the simple case.

If you have an application that uses a database on server 1 and you want that database replicated to server 2, you will set up server 1 as the source and server 2 as the target. Server 1 can be thought of as the master since changes your application makes to that database will be replicated (copied) to the target. The replication agent allows this to be set up and the table or file level.

The Replication Manager uses this concept to determine which tables or files are replicated. You will set up a publication to determine which files on the source (master) are available for replication. You will then set up a subscription to determine which server will be the target (destination) of the replicated files.

Note

The Replication Manager allows you to specify the publication and subscription in considerable detail. Not only will you select the source and target servers, you will also specify which tables or files are to be replicated.

When you set up publications and subscriptions, you will be able to specify many aspects of the replication, such as making it two-way replication.

Section	Description
High availability and scalability within and between data centers	Data replication is built into the FairCom server. Parallel processing threads replicate data at high speed while ensuring transaction consistency. Data can be asynchronously or synchronously replicated to one or more nodes.
High availability	High availability (HA) is the ability to remain available with no interruption to service during a system outage. Its purpose is to provide uninterrupted access to an application over a long time.
File/table requirements	This section describes the requirements for files/tables such as supported files, transaction processing, indexes and data files, and IFIL resources.
Replication network recommendations	This section describes the network recommendations for Replication Manager and replication clients.
Publications	This section describes what to replicate.
Subscriptions	This section describes where to replicate.
Plans	This section describes how to replicate.