8 Big Data Deployments In Detail

Oracle has launched a version of the Linux kernel, called the Unbreakable Enterprise Kernel, optimized for running Oracle software on Oracle hardware under Oracle's version of Linux.

Formerly called Oracle Enterprise Linux, with its support program known as "Unbreakable Linux," the Oracle distribution has been renamed Oracle Linux, with customers having the option of choosing a look-alike version of Red Hat Enterprise Linux or one with the Oracle-modified Unbreakable Kernel at its core. The term "unbreakable" has no precise significance among Linux developers; it's an Oracle marketing term.

While making it clear Oracle was departing from its past practice of offering only a Red Hat compatible version of Linux, Edward Screven, Oracle chief corporate architect, tried to emphasize, "We are not forking Linux. We are as compatible with Red Hat Enterprise Linux as before." He made his comments in Monday's keynote address to attendees of Oracle OpenWorld in San Francisco.

On the other hand, he also emphasized that the modified kernel in Oracle Linux "is best for running the Oracle database and Fusion middleware." One of the modifications is to make Linux run faster on large, non-uniform memory access (NUMA) servers. Screven didn't cite particular examples, but the former Sun Starfire, Stratus Technologies servers, and models from Sequent Computer, now part of IBM, all produce NUMA servers considered power database servers.

Linux kernel development has not paid as much attention to issues related to running on NUMA architectures as it has on more mainstream two-way and four-way servers. The Unbreakable Kernel will provide finer controls over the many CPUs in a NUMA system, said Screven.

The Unbreakable Kernel also incorporates T10 Data Integrity, a standard written by a group of storage vendors, which ensures data doesn't become corrupted while in transit between an application server and storage in a database. If packets are lost in transit or a piece of equipment acts erratically, current versions of the Linux kernel go ahead and store the data anyway. Storage vendors typically institute checksums to make sure no change in the bit count has occurred to the data as it moves from device to device.

"Data integrity extensions stops corrupt data from being written to disk," said Screven.

The Unbreakable Kernel is able to process Infiniband traffic up to twice as fast as other Linux kernels and "accesses solid state disks 137% faster" than other Linux kernels. Screven asserted that overall, the Unbreakable Kernel is 75% faster than Oracle's version of Red Hat Enterprise Linux, although that comparison means that two Linuxes built from different versions of the kernel are being compared.

The most recent release, 2.6.32, would show performance gains over a version several releases back. Red Hat Enterprise Linux undergoes extensive compatibility testing before releases, and its versions are often using kernels from the Linux development process that are 2-3 numbers or more behind the most recent release.

Oracle didn't say which release of the kernel it used in its Unbreakable Kernel distribution to make the speed claims, or what application or benchmark was used to derive the figure.

Screven said Oracle was willing to make use of innovations and speed-ups found in newer versions of the kernel, and will offer them in its Unbreakable Kernel version to customers ahead of their appearance in Red Hat Linux. He also said valuable innovations that originate in the community version may be pulled into the Unbreakable Kernel without waiting for them to complete their progression through the kernel development process, headed by Linus Torvalds and Andrew Morton.

When Screven says its Oracle Linux will remain compatible with Red Hat's, he appears to mean applications that run under Red Hat Enterprise Linux will also run under Oracle's Linux. That is, it will make no changes in the kernel that render it no longer backward compatible with the existing Red Hat version. It says changes that it implements in its Unbreakable Kernel version will be contributed back into the kernel development process and eventually adopted by Torvalds and his fellow kernel maintainers and then Red Hat.

Jonathan Corbet, editor of Linux Weekly News, posted Oracle's Unbreakable Kernel announcement Monday and commented that Oracle is introducing competition into Linux use based on the type of kernel adopted. That's not necessarily a bad thing, but in recent years Linux vendors have avoided competing on the kernel basis.

His post drew a question from a reader concerning the use of the "unbreakable" name: "Are they sure there are no security holes?" Corbet, a kernel developer himself, responded: "It's just a marketing term they use. It has no foundation in engineering."

Oracle says it now has 5,500 Linux customers. In addition, Oracle will deliver Version 11 of the Solaris operating system to customers sometime in 2011, said Screven.