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). I've also posted the modifications I've made so far to H2 to get it running on GaeVFS:
http://code.google.com/p/gaevfs/wiki/H2GAE My plans are to tackle the following issues next (in order): 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). 2) Create an H2 WriterThread implementation based on GAE Task Queues (as soon as Google provides support for this in Java). 3) Investigate what sort of caching might make sense for GaeVFS/H2 based on the GAE memcache API. Any feedback on what I've implemented so far, or advice on how I should proceed would be welcomed. Vince On Sat, Jul 11, 2009 at 2:12 PM, Thomas Mueller<[email protected]> wrote: > > Hi, > >> (1) getting it to work properly in a distributed environment >> with multiple GAE application instances accessing the same database; > > That will be hard, and in some cases it's the wrong solution... I > guess a more scalable solution is to use 'linked tables' that are > backed by the Google DataStore. > > But having a stable virtual file system backed by the Google DataStore > will help others as well, not only H2. > > Files greater than 1 MB is the most important missing piece I think. > > Some kind of file locking support would be great. Currently H2 doesn't > use file locking to ensure the database is only opened in one process, > instead it uses it's own 'cooperative file locking' protocol. But > regular file locking is relatively easy to add (in the class > FileLock). > >> Is anyone interested in this? > > I'm interested, and I'm sure others are interested as well. > > 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 -~----------~----~----~----~------~----~------~--~---
