About the Oracle Endeca Server software package

The Oracle Endeca Server software provides the query engine that serves as the foundation for all front-end applications utilizing it.

The software includes the Oracle Endeca Server, which is the management facility for administering the Endeca data domains. Front-end applications built on top of the Oracle Endeca Server can answer end-user queries and provide business analytics information to the front-application's users.

Note: The term Oracle Endeca Server is used in two related contexts: On the one hand, it is the name of the entire software package for the server. On the other hand, the Oracle Endeca Server is the management facility for administering your data domains.
The Oracle Endeca Server lets you administer your Endeca data domains. The Endeca data domain is where the source data records are stored after being loaded from your ETL client. With the Oracle Endeca Server, some of the operations you can perform are:

In addition, the Oracle Endeca Server constantly monitors the status of the running Endeca data domains and will automatically restart them (for example, if one crashes).

As the query engine, the Dgraph process of the Oracle Endeca Server uses proprietary data structures and algorithms that allow it to provide real-time responses to client requests issued to the data domain that is running on the server. The Dgraph process receives client requests via the application tier, queries the data files, and returns the results.

Each Endeca data domain contains a set of versioned Web services for loading, configuring, and querying the data. These Web services, together with the Bulk Load Interface, provide the interfaces to the Oracle Endeca Server.

About the Endeca Server cluster and the data domain cluster

A data domain cluster is composed of a set of nodes (Dgraph processes) all of which can serve query requests. If the data domain cluster is not read-only, one node is identified as the leader node; all other nodes are follower nodes. For read-only data domain clusters, all nodes serve as follower nodes. One copy of the index for the data domain is shared and used by all nodes. The Cluster Coordinator provides communication between the nodes in the data domain cluster. It also notifies the follower nodes about index updates and updates to the configuration.

If one of the data domain cluster nodes fails, queries continue to be processed by other nodes. A data domain cluster also provides increased throughput by the Oracle Endeca Server. By adding Endeca Server instances to an Endeca Server cluster that is hosting the data domain cluster, you can spread the query load across multiple Oracle Endeca Servers without the need to increase storage requirements at the same rate. Endeca Server instances can be added or removed dynamically, without having to stop the data domain cluster.

In the development environment, you can start with a single Oracle Endeca Server that is hosting a data domain (this is essentially a one-node data domain cluster). You can then expand your single instance implementation by adding more Endeca Server instances and expanding the data domain to utilize those instances. When you move to a production environment, you can duplicate a multi-node data domain cluster that you built in the development environment.

For information on installing and deploying an Endeca Server cluster, see the section in this guide.

For more information on the Endeca Server cluster and the data domain cluster, see the Oracle Endeca Server Cluster Guide.