Red Hat has announced that it has begun shipping the second rev and the first fully functional version of its Enterprise MRG real-time Linux. The Fedora Project, which is sponsored by Red Hat, has also put the alpha of its Fedora 11 development release in the field on time.

Enterprise MRG is a variant of the Red Hat Enterprise Linux stack that has been tuned to support messaging, real-time, and grid computing workloads rather than the standalone variant of Linux, which is tuned for file, database, and application serving. Enterprise MRG 1.1 was supposed to ship at the end of 2008, according to Red Hat's original plan, so it is a few months late.

Enterprise MRG replaces the generic Linux kernel with a real-time kernel based on the CONFIG_PREEMPT_RT patch set that was created by developers at Red Hat, Novell, IBM, Silicon Graphics, and a number of other vendors to make it more of a real-time operating system, one with a streamlined kernel offering the lowest possible latencies for applications. Novell's SUSE Linux Enterprise Real-Time, or SLERT, variant of SLES 10 is chasing the same market niche. The R in MRG is the part that financial services companies and defense contractors are interested in for their respective trading and weapons systems, where latency means money or death.

The M in MRG is for message queuing, and is designed for applications that pass lots of messages around between applications and servers, allowing relatively loose coupling of applications across servers. IBM's WebSphere MQ, Microsoft's Message Queuing Middleware, Tibco's Rendezvous financial transaction messaging, and the Java Messaging Service examples of the kind of messaging that Red Hat is talking about. But Red Hat's messaging within Enterprise MRG is based on the Advanced Message Queuing Protocol (AMQP), an open and standard implementation of messaging technology.

It is the G part of MRG that has been missing up until now, and that is because Red Hat's programmers have been integrating the Condor grid software developed by the University of Wisconsin into the Enterprise MRG product. When MRG went into beta in December 2007, Condor was not yet woven in and the release did not yet support the JBoss Enterprise SOA stack, either. Enterprise MRG 1.0 was launched in June 2008 as a commercial product, but the grid components were still only in technology preview.

With MRG 1.1, Red Hat has tweaked the real-time kernel so it works better on processor chips that have multiple cores, which is important as Intel and AMD move from two to four and soon to six or eight cores on processors aimed at servers.

MRG 1.1 also has native InfiniBand and Remote Direct Memory Access (RDMA) drivers for lower-latency clustering. The RDMA features, which works over InfiniBand or Ethernet networks (depending on the underlying hardware support for RDMA, of course), allow nodes on a cluster to move data between nodes directly into and out of memory in the nodes rather than having to go through the I/O stack. This really cuts down on latency.