Updates of hackage-server and data loss

Duncan Coutts duncan.coutts at googlemail.com
Mon Feb 6 19:07:56 CET 2012

On 6 February 2012 15:22, Erik Hesselink <hesselink at gmail.com> wrote:
> Hi all,
> We run hackage-server internally at Silk. Every time we update to a
> new version, it is unable to read our old data. Is the acid-state
> being versioned correctly? Or is this expected behavior? It is very
> annoying for us. If this is expected, is there a way to work around
> it?

Our approach to versioning is not via acid-state by by a database
backup/restore method. We export all canonical data to a tarball of
text and other standard format files. The reason we do this is because
we don't trust that the binary data format is sufficient for long term
preservation of all the data. Because we are using dump/restore, we
make no attempt to use the acid-state versioning scheme (it's
plausible we might do so in future as an extra, but probably not until
there are actual releases).

The backu[/restore is done via the commands 'hackage-server backup'
and 'hackage-server restore'. It is also possible to generate backups
while the server is running by sending a USR1 signal (kill -USR1

Note also that testing of the backup/restore method is not quite
complete, but the testing framework for it is in place I think.


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