A Holistic View of High Availability

What does it take to have highly available databases? According to John Posavatz, Vice President of Product Management for Neverfail Group, it’s not just a matter of setting up a high-availability server, or even monitoring it for the common problems you might expect. It's often the problems you don't expect—or the ones that crop up as your server environment changes over time—that cause problems.

Related: The Price of High Availability

"Very rarely does a server simply fail," says Posavatz. "When a server goes down, it’s often because someone made a simple mistake in configuration or added software without realizing all the ways it could affect the server." For example, a common cause of database corruption in SQL Server environments is antivirus software. When file-level antivirus software performs its scans, it can detect anomalies and quarantine critical database files, thus corrupting the entire database.

Neverfail Group realized that preventing this kind of problem is at the core of keeping data highly available. The company has released the latest version of its SCOPE tool, an analysis component that works with the Neverfail high availability server products, including Neverfail for SQL Server. The SCOPE tool helps you prevent server problems in several ways. First, before you install Neverfail, you can use SCOPE to scan your servers, assess their reliability, and eliminate potential problems before you start. Then, once Neverfail is installed and running on your system, SCOPE continually assesses the ongoing health of your servers and proactively addresses any potential reliability problems. The tool benefits from an ongoing connection with Neverfail's rule repository, which collects information about problems that other users encounter and incorporates the new information into its scans.

It's these preemptive warnings that make Neverfail's approach unique, says Posavatz. He emphasizes, "almost all of Neverfail's customers make backups, but if you’re to the point that you’re restoring data from a tape backup, then something has gone horribly wrong." Neverfail’s approach is to look at not just your server setup, but the composition of your entire system to see how all the pieces in your environment affect your server and prevent potential problems. "Unless you’re taking a holistic view of your system," says Posavatz, "you’re likely to miss the one thing that can bring your servers down."