"Hello everyone! We are happy to say that the 1.12 release is now available!" began Matthew Dillon, announcing the latest stable version of DragonFly BSD. The project's home page explains, "DragonFly is an operating system and environment originally based on FreeBSD. DragonFly branched from FreeBSD in 2003 in order to develop a radically different approach to concurrency, SMP, and most other kernel subsystems." Regarding the latest release, Matt explained:
"This release is primarily a maintenance update. A lot of work has been done all over the kernel and userland. There are no new big-ticket items though we have pushed the MP lock further into the kernel.
"The 2.0 release is scheduled for mid-year. Of the current big-ticket item work, the new HAMMER filesystem is almost to the alpha stage of development and is expected to be production ready by the mid-year 2.0 release."
"HAMMER won't be ready for sure (things take however long they take), but the hardest part is working and stable and I'm just down to garbage collection and crash recovery," noted Matthew Dillon, discussing the status of what is ultimately intended to be a highly available clustering filesystem. The upcoming DragonFlyBSD release this month was originally intended to be 2.0 with a beta quality HAMMER, but the decision was recently made to call the release 1.12 while HAMMER continues to stabilize. Matt continued, "HAMMER is really shaping up now. Here's what works now: all filesystem operations; all historical operations; all Pruning features". During the discussion, he was asked how he planned to support multi-master replication, in reply to which he began:
"My current plan is to use a quorum algorithm similar to the one I wrote for the backplane database years ago. But there are really two major (and very complex) pieces to the puzzle. Not only do we need a quorum algorithm, but we need a distributed cache coherency algorithm as well. With those two pieces individual machines will be able to proactively cache filesystem data and guarantee transactional consistency across the cluster."