Hi, > I've just released a new version of GaeVFS (version 0.3) that supports > files greater than 1 MB and also adds support for random read/write > file access (both of these were added for H2).
That's great! > 1) Implement a distributed file locking mechanism for GaeVFS that > works across multiple JVM instances; implement exclusive write access > to files across multiple JVMs. (I'll look at the H2 FileLock class as > you suggest, but would like a general solution for GaeVFS that isn't > just for H2). H2 currently uses a special 'cooperative locking mechanism', probably it doesn't make sense if you try to emulate this. Instead, I guess it would make more sense to support just 'lock' and 'unlock', in the spirit of: http://java.sun.com/javase/6/docs/api/java/nio/channels/FileChannel.html#tryLock() http://java.sun.com/javase/6/docs/api/java/nio/channels/FileLock.html#release() This can then be adapted to H2. > 2) Create an H2 WriterThread implementation based on GAE Task Queues > (as soon as Google provides support for this in Java). I didn't know about this... interesting. I would wait to implement this until Google supports it. > 3) Investigate what sort of caching might make sense for GaeVFS/H2 > based on the GAE memcache API. Maybe the file system could be made faster if the last few write operations are first only written to the memcache API? Not just for H2, but I guess many applications that use a file system could benefit from a 'write behind cache'. Or maybe first cache writes in the local memory, after some delay apply them in the memcache, and still later apply them in the data store. Many applications don't require that the changes are written to disk immediately. The biggest benefit would probably be for application that don't buffer writes. Regards, Thomas --~--~---------~--~----~------------~-------~--~----~ You received this message because you are subscribed to the Google Groups "H2 Database" group. To post to this group, send email to [email protected] To unsubscribe from this group, send email to [email protected] For more options, visit this group at http://groups.google.com/group/h2-database?hl=en -~----------~----~----~----~------~----~------~--~---
