Last time I check, multi-process byte-range file locking was a mess. I&#x27;m surprised by your statement about BerkeleyDB, because as far as I can tell it simply cannot be safely implemented.<p>This blog post (2010) explains what the status is <a href="http:&#x2F;&#x2F;0pointer.de&#x2F;blog&#x2F;projects&#x2F;locking.html" rel="nofollow">http:&#x2F;&#x2F;0pointer.de&#x2F;blog&#x2F;projects&#x2F;locking.html</a><p>If something has changed since then (or that article is incorrect), please let me know.