E-Business - always available (page 1 of 8)

Customer and user expectations are significantly higher than even just a few years ago, and there's even more pressure on businesses to ensure continuous availability of core systems for internal users and external customers.

"More and more organizations' business processes are extremely dependent on their applications and infrastructure, so if there are any outages in the environment, it's very costly from a business perspective," says Donna Scott, vice president and distinguished analyst at Gartner, Inc., in Stamford, Connecticut. "It takes a very well-designed and well-managed environment to mitigate the risks of downtime and prevent it from happening or, if you can't prevent it from happening, to enable as quick a recovery as possible."

In its simplest form, a high-availability plan encompasses three aspects: resiliency (making sure applications and systems are as reliable as possible), recoverability (ensuring that if a component does fail, there's a way to recover within a given time period), and continuous operation (ensuring that systems or applications are available even during maintenance activities).

Whereas disaster recovery is concerned with getting core business (and IT) systems up and running again after an unplanned outage, high availability involves proactively ensuring that there's no single point of failure for essential systems (be they applications, databases, networks, storage, or any other IT component). "High availability involves both planned and unplanned outages," says Charles Garry, senior program director of infrastructure services at Meta Group, Inc. "Planned outages occur for things like application upgrades, hardware upgrades, patches, and basic maintenance. Unplanned outages can include user error, operator error, and actual hardware failure."

In fact, although most people probably think about a server crashing, a disk controller dying, hardware or software glitches, or catastrophic disasters when the topic of high availability comes up, there's another side to the story. "Forty percent of downtime, on average, is caused by operations errors," says Scott. "Oracle, like the rest of the industry, focuses on trying to reduce manageability requirements for software products. This not only reduces the amount of labor needed to manage them but also reduces the chance for errors from touching a product."

But high availability isn't just about databases, application servers, networks, backups, or new grid technologies; it's also about users and their expectations—giving users what they want, when they expect it, at the level of performance they expect. Advances in a wide variety of technologies, including products such as Oracle Real Application Clusters (RAC) and Oracle Data Guard as well as new functionality such as the Flashback capabilities in Oracle Database 10g, not only make it easier to meet these user expectations but also significantly reduce the manageability and development requirements associated with highly available applications.

"We're not trying to build a system in which no piece ever fails; we're trying to build a system in which we can tolerate the failures of individual pieces and have the system as a whole keep going," says Juan Loaiza, Oracle vice president of Data and Systems Technologies. "We've integrated several technologies into our stack that basically allow organizations to assemble a lot of low-cost servers, storage, and network technologies to create a highly available system that is also highly scalable.