1 Introduction and Roadmap

This chapter includes introductory information on how and why to use this guide and high availability environments.

This chapter includes the following topics:

Section 1.1, "How to Use This Guide."
Section 1.2, "New and Changed Features in This Release"
Section 1.3, "What is High Availability?"
Section 1.4, "High Availability Solutions"
Section 1.5, "Understanding the Oracle Fusion Middleware Standard HA Topology"

1.1 How to Use This Guide

Use this document as a reference guide for information on high availability concepts and tasks as you set up a highly available environment.

Before you use this guide, you must have a standard installation topology set up for your product. This is the required starting point for setting up high availability. See the topics "Understanding the Oracle Fusion Middleware Infrastructure Standard Installation Topology" and "Roadmap for Installing and Configuring the Standard Installation Topology" to set up the standard installation topology.

Table 1-1 describes tasks to set up a highly available environment and resources for information that is not in this guide.

Table 1-1 Setting up a Highly Available Environment

Task	Description	For more information
Performing administrative tasks and preparing your environment	Common tasks to perform on a newly-created domain.	See the topic "Administering and Preparing your WebLogic Domain for High Availability" in your product installation guide.
Planning your WebLogic Server Installation	Covers understanding your topology and determining the distribution, components and features you need	See the guide Planning an Installation of Oracle Fusion Middleware
Installing the WebLogic Server Software	Describes how to start the installation process and progress through the installation screens	See the topic "Installing the Oracle Fusion Middleware Infrastructure Software" in your product installation guide.
Configuring a domain	Creating and configuring a domain	See the topic "Configuring your Oracle Fusion Middleware Infrastructure Domain" in your product installation guide.
Managing Oracle Fusion Middleware	Includes how to: start and stop, change ports, deploy applications, and back up and recover Oracle Fusion Middleware.	See Oracle Fusion Middleware Administrator's Guide
Monitoring and optimizing performance in the Oracle Fusion Middleware environment.	For components that impact performance, use multiple components for optimal performance, and design applications for performance.	See Oracle Fusion Middleware Tuning Performance Guide
Setting up a product-specific enterprise deployment	Oracle best practices blueprints based on proven Oracle high availability and security technologies and recommendations for a product-specific enterprise deployment.	See your product's Enterprise Deployment Guide
Administering the product environment	To deploy, manage, monitor, and configure applications using the product.	See your product's Administrator's Guide
Configuring Node Manager	Node Manager enables you to start, shut down, and restart the Administration Server and Managed Server instances from a remote location, making this an essential utility for any high availability environment.	See the guide Administering Node Manager for Oracle WebLogic Server

1.2 New and Changed Features in This Release

Oracle Fusion Middleware 12c Release 1 (12.1.2) includes the following new and changed concepts and features from previous Oracle Fusion Middleware releases:

Middleware topology changes. See "Understanding Middleware Architecture Design."
Support for a domain-based Node Manager. See "What is Node Manager?"
Managing system components. You no longer use OPMN agent and opmnctl command line utility in Oracle Fusion Middleware. You manage system components with the WebLogic Management Framework, which includes management tools such as WLST. For more information, see "What is the WebLogic Management Framework?" in the guide Oracle Fusion Middleware Understanding Oracle Fusion Middleware and WLST Command and Variable Reference.
Redefining of the Oracle home and elimination of the Middleware home. See "New and Deprecated Terminology for 12c Release 1 (12.1.2)" in Understanding Oracle Fusion Middleware Concepts.
Coherence replaces the Java Object Cache. See Section 2.4, "Coherence Clusters and High Availability".

1.3 What is High Availability?

High availability is the ability of a system or device to be available when it is needed.

A high availability architecture ensures that users can access a system without loss of service. Deploying a high availability system minimizes the time when the system is down, or unavailable, and maximizes the time when it is running, or available.

High availability comes from redundant systems and components. You can categorize high availability solutions by their level of redundancy into active-active solutions and active-passive solutions.

An active-active solution deploys two or more active servers and can be used to improve scalability and provide high availability. In active-active deployments, all instances handle requests concurrently. Oracle recommends active-active solutions for all single-site middleware deployments. Active-passive solutions deploy an active instance that handles requests and a passive instance that is on standby.

1.4 High Availability Solutions

You can categorize high availability solutions into local high availability solutions that provide high availability in a single data center deployment, and disaster recovery solutions.

Local high availability solutions can protect against process, node, and media failures, as well as human errors, ensuring availability in a single data center deployment.

Disaster recovery solutions are usually geographically distributed deployments that protect your applications from disasters such as floods or regional network outages. You can protect against physical disasters that affect an entire data center by deploying geographically-distributed disaster recovery solutions. For detailed information about disaster recovery for Oracle Fusion Middleware components, refer to the Oracle Fusion Middleware Disaster Recovery Guide

1.5 Understanding the Oracle Fusion Middleware Standard HA Topology

Figure 1-1 shows the recommended standard high availability topology for a local, highly available Oracle Fusion Middleware deployment.

This deployment is consistent with the infrastructure standard installation topology and Oracle HTTP Server standard installation topology if you followed instructions in the Oracle Fusion Middleware Installing and Configuring the Oracle Fusion Middleware Infrastructure and Installing and Configuring Oracle HTTP Server guides.

Figure 1-1 Oracle Fusion Middleware Highly Available Deployment Topology (Typical Enterprise)

The text that follows this figure describes it.

Description of "Figure 1-1 Oracle Fusion Middleware Highly Available Deployment Topology (Typical Enterprise)"

This topology represents a multi-tiered architecture. Users access the system from the client tier. Requests go through a hardware load balancer, which routes them to Web servers running Oracle HTTP Servers in the web tier. Web servers use Proxy Plug-in (mod_wl_ohs) to route requests to the WebLogic cluster in the application tier. Applications running on the WebLogic cluster in the application tier then interact with the database cluster in the data tier to service the request.

Table 1-2 describes elements in Figure 1-1.

Table 1-2 Description of the Elements in the Oracle Fusion Middleware Infrastructure Standard High Availability Topology

Element	Description and Links to Additional Documentation
APPHOST	Refers to the machine that hosts the application tier.
WEBHOST	Refers to the machine that hosts the web tier.
WebLogic Domain	A logically related group of Java components, in this case, the Administration Server, Managed Servers, and other related software components. For more information, see "What is an Oracle WebLogic Server Domain?" in Understanding Oracle Fusion Middleware.
Administration Server	The central control entity of a domain which maintains the domain's configuration objects and distributes configuration changes to Managed Servers.
Enterprise Manager	Oracle Enterprise Manager Fusion Middleware Control. This is the main tool that you use to manage a domain.
Cluster	A collection of multiple WebLogic Server instances running simultaneously and working together.
Machine	Logical representation of the computer that hosts one or more WebLogic Server instances (servers). Machines are also the logical glue between WebLogic Managed Servers and the Node Manager; to start or stop a Managed Server with Node Manager, the Managed Server must be associated with a machine.
Managed Server	Host for your applications, application components, Web services, and their associated resources. For more information, see "Oracle Enterprise Manager Fusion Middleware Control" in Understanding Oracle Fusion Middleware.
Infrastructure	Collection of services that includes: Metadata repository (MDS) This contains metadata for Oracle Fusion Middleware components, such as the Oracle Application Developer Framework. For more information, see "What is the Metadata Repository?" in Understanding Oracle Fusion Middleware. Oracle Application Developer Framework (Oracle ADF) Oracle Web Services Manager (OWSM)