Requirements Definition
The first major phase in delivering a successful Oracle RAC implementation is defining the actual goals of the project. The Requirements Definition step involves identifying and documenting the features and functionality delivered during the implementation phase of the project.

As you proceed with your Oracle RAC implementation, you will continually come back to your requirements lists. Having a set of documented requirements will lend direction to your Oracle RAC project. Without it, you will find the project difficult to manage, as new, unexpected changes creep into the project’s implementation.
 

Avoiding Pitfall #1: Make sure your key business and technical personnel actively participate in identifying the requirements for the project. Clearly communicate all requirements to the project stakeholders, including key management staff, technical staff, and end users.

Step 1 – Defining Project Scope
The first step in the Requirements Definition phase is defining the project scope. The project scope, a collection of details that justify the business need for the project, describes the project’s high-level deliverables. The project scope is sometimes referred to as “business requirements.”

To determine the project scope, ask yourself the following questions:

• What are the business objectives of the project?

• What is the project trying to accomplish?

• What are the key benefits of successful project completion?

A sample project scope document detailing the high-level goals of a sample Oracle RAC project is shown below.
 

Step 2 – Defining the Project Team
Defining the project team involves identifying the individuals who will contribute to the project’s deliverables and the ones who will complete the tasks within the project plan. These individuals may include persons from multiple areas of your organization, including executive staff, business analyst staff, and technical staff.
 
The following matrix describes the makeup of a typical Oracle RAC project, describes their function, and specifies the steps at which they may contribute to the project.

The responsibilities of your Oracle RAC project team members may differ from site to site, depending on the size of the site and the system requirements.
 
While you’re putting this project team together, the most qualified staffers for the project may be unavailable. This constraint may force you to go with the people who are available. In such a situation, you can lessen implementation risks by sending your project team members to get the appropriate technical training. Technical training often leads to reduced project risk and higher-quality project deliverables.

Step 3 – Defining Service-Level Requirements
The third step in the requirements definition phase is defining the service-level requirements. Service-level requirements are the levels of service your Oracle RAC project implementation is expected to support. They document the service-level expectations and operational requirements and provide guidelines for handling delays and failures.
 
Service-level requirements can be broken up into two categories of requirements: service-level requirements and operational requirements.
 
Service-level requirements assist in aligning the Oracle RAC technology implementation with the project’s scope—the project’s business goals. You begin to identify your service-level requirements by first analyzing requirements of existing systems. This analysis includes reviewing existing system operational, technical, and support procedures and documentation.
 
You can further identify service-level requirements by asking questions such as
 
• What are the critical business hours during which the Oracle RAC system is expected to be online?
 
• What are the various levels of service required of the system?
 
• What are the minimum acceptable levels of performance and availability?
 
• What are the procedures for handling delays and failures?
The answers to these questions are typically grouped into a rated, tiered service-level-requirements matrix that defines the differing levels of service.
 
Below is a sample service-level-requirements matrix. Exact definitions and the number of tiers will depend on your individual organizations and business units.

Operational requirements define the procedures required to maintain the Oracle RAC system and the service-level requirements defined above. Often, operational requirements include information on scheduled maintenance outages, system startup and shutdown, system backups, Oracle RAC system availability, failover procedures, and disaster recovery plans.

You identify operational requirements by asking questions such as

• How do we maintain Oracle RAC system performance baselines?

• How long should maintenance operations take?

• Which maintenance and backup operations should be performed “online”?

• What are the required procedures for shutting down and starting up the system?

• What type of backups should be performed to maximize system recoverability?

• How do we prepare for disasters?

A sample Oracle RAC operational requirements list is shown below.

Step 4 – Defining the Project Schedule
The last step in the requirements definition phase is defining the project schedule. Schedule development is one of the most critical factors of project success, because you need to make sure you have enough time to build your Oracle RAC solution while meeting all of the requirements defined above.

Schedule development involves detailing all of the tasks involved in building the system, assigning a duration to each task, and sequencing the tasks in the optimal order.
 

 
Occasionally, multiple tasks in your project schedule can be performed at the same time. Strategically parallelizing your work efforts often leads to on-time delivery and reduced project costs.

A sample high-level Oracle RAC project schedule is shown below. It demonstrates common tasks performed during an Oracle RAC deployment.
 

An appropriately detailed project schedule enables the Oracle RAC team to track the project schedule’s progress while assisting it in proactively responding to schedule delays. When a schedule change is required, make sure you thoroughly document the changes. The original project schedule, along with the report of changes, creates a powerful tool for estimating project schedules for future projects.
 

 
After defining and documenting the project scope, project team, service-level requirements, and project schedule, implement a strong change-control system. Carefully manage any changes to the requirements, to keep the costs within budget and the project on schedule.

Technical Architecture Design and Build
The second major phase in delivering a successful RAC implementation is determining and implementing the technical architecture specifications of your Oracle RAC deployment. The technical architecture details the hardware, software, and configuration that will constitute the new system. Because most Oracle RAC implementations focus on moving from single-instance environments to Oracle RAC instance environments without a complete redesign of their applications and databases, you will both design and build the Oracle RAC environment as you proceed through this phase.
 
The following steps explain how to transform the requirements into a working design.

Step 1 – Determine the Hardware and Software Specifications
This step involves taking the service-level requirements and operational requirements, defined above, and translating them into hardware and software specifications. It also considers hardware compatibility, specific operating system requirements, and Oracle RAC–specific software requirements.

Use the Hardware/Software Considerations Chart below as a checklist and for documenting the decisions made in this step. For your individual implementation, fill in the actual hardware-component and software-component items you are using for your project.

When filling in this chart, ask questions such as
 
• Does the component assist in meeting service-level requirements?
 
• Is the component and the quantity of this component sufficient to meet the operational requirements?
 
• Is the component compatible and/or certified to work with the other hardware components?
 
• Is the component compatible and/or certified to work with the operating system?
• Does the component meet the Oracle RAC software requirements?
 
• Is Oracle RAC certified and supported to run on the component?
 

 
Step 2 – Implementing the Specifications
After completing the checklist above, it’s time to construct the Oracle RAC environment.

These tasks include the following:

I. Configure the Server Hardware
   A. Install the CPUs, memory, and local disk
   B. Install and configure the HBAs, network cards, and networking components
   C. Configure the hardware interconnects
   D. Install and configure storage switch devices, and attach them to shared storage
 
II. Configure the Operating System
   A. Install the operating system
   B. Configure operating system kernel parameters
   C. Configure the hangcheck-timer or interconnect heartbeat module
   D. Create operating system user groups and users
   E. Create and configure shared storage devices
   F. Install and configure raw partitions or Oracle Cluster File System
   G. Configure Secure Shell (SSH)
 
III. Configure the Oracle Software
   A. Install Oracle Clusterware
   B. Install the Oracle server software
   C. Configure Automatic Storage Management (ASM)
   D. Create the databases
   E. Create the database instances
   F. Create services
   G. Create Oracle Clusterware application profiles
 
IV. Operational Tasks
   A. Perform data loads
   B. Perform index builds
   C. Set up OS and database backups
   D. Create standby/Oracle Data Guard environments
   E. Install and configure performance monitoring utilities, such as Oracle Enterprise Manager Grid Control

RAC System Testing
An Oracle RAC test strategy should consist of at least four types of testing: proof-of-concept testing, unit testing, integration testing, and load testing.
This test strategy is not a function that is to be performed separately from the above phases; instead, it is a process that is integrated into the Definition, Design, and Build phases.

This section highlights the four types of testing and identifies the project phase in which each test should be performed.

Proof-of-Concept Testing
Proof-of-concept testing is testing of the feasibility of a concept. It can mean testing a new technology, a new software architecture, or new hardware. Proof-of-concept testing allows the project team to test the validity of project decisions and gives them the ability to quickly make important decisions about the project’s direction. Proof-of-concept testing is usually performed during the Service-Level-Requirements and Technical Architecture Design and Build steps.
 

 
Unit Testing
Unit testing involves the testing of a single hardware or software component or the testing of a single application or application module. This isolated test determines whether a single component or module is working within its specified requirements.

Oracle 10g Release 2 includes a verification utility called (CVU), which is a tool for unit-testing the hardware and software configuration of an Oracle RAC node. Use the utility for verifying the configuration of the Oracle RAC node, for checking the operating system, and for checking the network setup.

One important element of unit testing is the inclusion of “destructive testing,” in which the tester simulates abnormal activity and tries to break the system. An example of a destructive test in an Oracle RAC environment is to intentionally corrupt your Oracle Cluster Registry (OCR) and perform the steps required to get the system up and running again. A test such as this allows the team to identify vulnerable areas in the system and to prepare an action plan.
 

 
Integration Testing
Integration testing involves verifying that multiple hardware, software, or application modules are working together. Integration tests determine if the system is running according to specifications.
 

 
Stress Testing
Stress testing, also referred to as load testing or system testing, is an end-to-end test that simulates a live production load. It is used to determine if the system can sustain production usage levels and if service-level requirements can be met and to gather performance data. It is also used to predict current and future usage capacity. Stress testing is often performed after all of the above tests return with positive results and after the hardware, software, and application components have been fully configured. Because it represents a major project milestone, it can be considered a separate project phase.
 

 
Operational Readiness
When should you go live with your new system?
The previous project phases and their associated steps facilitate a litmus test for assessing the readiness of the new system. Although the specifics of a completion checklist will depend on your particular site, the following generic outline will help you define, design, build, and test your Oracle RAC implementation.
 
Deciding your operational readiness depends on the number of completed tasks, the amount of time left in the project schedule to complete any uncompleted tasks, and the stability of the new system in its current state. It also depends on how many of the project requirements have been met.
 
Below is a detailed project plan with all of the implementation phases and steps this article has covered. It includes an integrated test plan and a “Critical to Launch?” column to help you determine if that particular item is absolutely required to bring the system online—or if that particular item can be brought online after the system launch.