To avoid performance problems we changed the way files are stored on disk
when you choose to do so (which is default for postgresql in 1.7).
This is a last-minute change before the release of 1.7, because we wanted to
avoid that this change would happen after the release, causing the need for
everybody using this release (and postresql) to 'convert' their blob-dirs.
Now it is only needed for people already using 1.7 builds, but to ease
transition for them (er, which probably are mainly us selves..), we added a
tool in the admin-pages.
Cite from release-notes:
- Storing blobs (e.g. images) on disk has changed.
Blobs are now stored as follows:
The number of the object containing the blob is broken up in parts. The 3 least
significant digits are ignored.
The remaining digits are divided by powers of hundred (pairs of digits of 2).
These are then broken up in nested directories.
For instance, the field 'handle' of node with number 5447637 is stored as:
data/databasename/basename_buildername/54/47/5447637.handle
while the same field of node number 1205 is stopped as:
data/databasename/basename_buildername/01/1205.handle
where 'databasename', 'basename' and 'buildername' are depending on configuration
and type of the
node.
This improves performance on systems when you get a large number of binary fields.
Note: if you are upgrading from 1.7.0 RC1 you need to convert, because this
'breaking up' into
directories did not yet exist then.
Note: if you are upgrading from 1.6 or early 1.7 builds and used to store blobs on
disk using the
'old' storage implementation or the 'support' implementation (from < 1.6), then too
you need to
convert if you want to use the 'new' storage now (which you want). Note that the
'databasename'
and 'basename' parts are new in the path (these make it easier to toggle between
configurations).
Make sure the old 'blobdatadir' dir is now WEB-INF/data (use e.g. a symlink)
You can convert the blobs via the admin pages /mmbase/admin admin->BLOBS (which can
also be used
to migrate from blobs-in-database to blobs-on-disk).
on behalf of the storage project,
Michiel
--
Michiel Meeuwissen
Mediapark C101 Hilversum
+31 (0)35 6772979
nl_NL eo_XX en_US
mihxil'
[] ()
