Oracle 12.1 and High Availability — How is It Achieved?

High availability (HA) is no longer a buzzword but a business requirement. Businesses today need to have web applications running reliably on a 24/7 basis, across a variety of platforms — desktops, laptops and mobile devices. Think web applications, and the first thing that comes to mind are the databases at the backend of those applications.

Let’s look at the backbone of HA — the databases. Database downtime results in quantifiable loss in terms of sales and revenue and loss that cannot be quantified — customer dissatisfaction and negative feedback.

Application high availability is the net result of using relevant software and hardware technologies plus implementing best practices in the deployment of the infrastructure components — servers, clusters, operating systems, and most definitely databases.

According to Oracle:

“Users who want their systems to be always ready to serve them need high availability. A system that is highly available is designed to provide uninterrupted computing services during essential time periods, during most hours of the day, and most days of the week throughout the year; this measurement is often shown as 24×365. Such systems may also need a high availability solution for planned maintenance operations such as upgrading a system’s hardware or software.”

In this blog post we will briefly look at some of the technical capabilities of Oracle 12.1 that help minimize planned and unplanned downtime, therefore delivering HA by design. You can also download Datavail’s new white paper, Compelling Reasons to Upgrade to Oracle 12.1, for more information.

Application Continuity with Transaction Guard

The ability of an application to recover from specific scenarios where an inflight transaction is not successfully completed, due to any number of diverse reasons, is known as application continuity. Applications designed with such a high degree of recoverability and continuity contribute to the high availability of the system.

Transaction Guard is an essential component of Oracle 12.1. It has a built-in protocol and API. By using the API in error handling and exception routines, end users can ensure consistency, recoverability and accuracy of transactions in case of outages. Transaction guard can be used to design robust applications that have high availability.

Oracle Real Application Clusters (RAC)

Individual database servers are a potential single point of failure. If the server goes down due to hardware failure or any other possible reason, the database goes offline and application availability is affected.

Oracle RAC is Oracle’s clustering technology that ensures uninterrupted access to the database in a clustered server pool. This technology provides the additional benefits of scalability as the database has access to the combined memory and processing power of all servers in the cluster.

Oracle Automatic Storage Management (ASM)

Oracle ASM is an integrated file system and volume management software included with the Oracle database software. It uses the concept of Disk Groups that allow the DBAs to dynamically add disks to a group.

The Oracle ASM technology mirrors and stripes the disks within the disk group. In case a read operation is unsuccessful because of a corruption in a block of data, the ASM system transparently replaces that corrupted data from an uncorrupted block on the disk.

This is just an example of the power of the ASM technology. It is one of the essential components of the Oracle stack that can contribute to high availability of deployed Oracle databases. It is the de facto recommended storage technology for Oracle databases and Clusterware.

These are a few examples of technology features of the Oracle stack that indicate the company’s commitment towards providing simple yet effective high availability solutions at a low cost. The company has outlined several design principles and best practices under the Oracle Maximum Availability Architecture.

For more information on the new features of Oracle 12.1 and how to upgrade, please contact us today or download our new white paper, Compelling Reasons to Upgrade to Oracle 12.1. Datavail is a specialized IT services company focused on Data Management with solutions in BI/DW, analytics, database administration, custom application development, and enterprise applications. We provide both professional and managed services delivered via our global delivery model, focused on Microsoft, Oracle and other leading technologies.