Distributed lock manager: Difference between revisions

Revision as of 06:23, 12 May 2009

Revision as of 13:48, 12 May 2009

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[[OCFS|OCFS2]], the Oracle Cluster File System was added<ref>http://www.kernel.org/git/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commit;h=29552b1462799afbe02af035b243e97579d63350</ref> to the official [[Linux kernel]] with version 2.6.16, in January 2006. The alpha-quality code warning on OCFS2 was removed in 2.6.19.

Red Hat's cluster software, including their [[Distributed lock manager|DLM]] and [[Global File System]] was officially added to the Linux kernel <ref>http://git.kernel.org/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commit;h=1c1afa3c053d4ccdf44e5a4e159005cdfd48bfc6</ref> with version 2.6.19, in November 2006.

Both systems use a DLM modeled on the venerable [[OpenVMS|VMS]] DLM.<ref>http://lwn.net/Articles/137278/</ref> Oracle's DLM has a simpler API. (the core function, <code>dlmlock()</code>, has eight parameters, whereas the VMS <small><code>SYS$ENQ</code></small> service and Red Hat's <tt>dlm_lock</tt> both have 11.)

==Google's Chubby lock service==

[[Google]] has developed ''Chubby'', a lock service for loosely-coupled distributed systems<ref>http://labs.google.com/papers/chubby.html</ref>. It is designed for coarse-grained locking and also provides a limited but reliable distributed file system. Key parts of Google's infrastructure, including [[Google File System]], [[BigTable]], and [[MapReduce]], use Chubby to synchronize accesses to shared resources. Though Chubby was designed as a lock service, it is now heavily used inside Google as a [[name server]], supplanting [[Domain name system|DNS]]. {{factFact|date=May 2009}}

==SSI Systems==