9 May
2017
9 May
'17
9:20 a.m.
On Sun, May 7, 2017 at 2:12 PM, Vincent Massol <vincent(a)massol.net> wrote:
Hi Thomas and all,
I don't think you fully understood me. I'm not proposing a new format
here, I'm telling you we already have a format and associated
input/output filters which support both wiki pages and extensions and
contrary to what you propose also support any custom data provided by
extensions current and future (prepared mails in database, events
stream data, instance id even if I think we should move that in the
permanent dir which would fix several issues we currently have, etc.).
As I said the idea would be to stop using XAR for general backup (job
it does not do well anymore compare to the old times where all was in
wiki pages), not having several backup formats.
On 6 May 2017, at 18:39, Thomas Mortagne
<thomas.mortagne(a)xwiki.com> wrote:
IMO we should keep XAR format for applications and use a different
format for backups.
Let me explain why I think it would be better to use the XAR format for this:
* It’s simpler to have 1 format than several for our users. It’s also confusing to have 2
formats that similar things (e.g. being able to backup/restore pages with both
formats).We’re already going to introduce a new XIP format too. A third one would increase
the complexity.
* The XAR name is not limited to saving wiki pages. It actually means “XWiki Archive”
which is perfect for representing the backup of a full XWiki instance.
* Users already know the XAR format (it’s documented) for backup/restore. Introducing a
new format would cause major confusions.
Yes they know it's a ZIP with wiki pages in it, what you propose is a
new format in practice even if you reuse an old name for it.
* Adding new data to the XAR format doesn't make it incompatible with previous
versions.
It will not crash the importer because it's bulletproof enough but you
will get tons of errors because it will hit a lot of files it does not
understand. There is no room right now for custom data in the XAR
format specifications.
On the proposal itself I really don't think it's that simple: just
package the permanent dir as it is is not a good idea IMO. How do you
merge it in the running instance which already have a permanent dir
with different things in it ? How extension manager or any other
extension will know you added stuff in there and how the generic
import even know what to do in case of collision ? Also when using
filesystem attachment you end up duplicating them both in wiki pages
and permanent directory. When talking about importable format I really
prefer a format organized specifically for import/export that just zip
the permanent directory which is really not designed for it. It's way
better to let extensions deal with those data the way they want which
is what happen in the Filter XML format currently.
* We can reuse the same UI and make modifications to it. Like for example a checkbox to
save the permanent directory data in the XAR (we should compute and display the size as a
hint in the UI). In addition I believe we should also support saving the generated XAR
locally on the server if the user wishes to since that XAR could get very large (several
GB potentially with large attachments).
* We’re talking about the XAR format here.
In term of implementation we can definitely use the
Filter module (and we should - I thought it was already the case).
What makes you think it's not the case ?
What do others think?
Thanks
-Vincent
--
Thomas Mortagne
We actually already have this new backup format I
think: the XML
format you can find in Filter module. It currently support both wiki
pages and extensions. Also this format/module is extensible enough for
any extension to add its own data without touching it (it does not
know anything about wiki pages or extensions for example). What is
missing is probably a dedicated backup oriented UI which would be
based on this format instead of XAR format.
On Sat, May 6, 2017 at 12:11 PM, Vincent Massol <vincent(a)massol.net> wrote:
Fixed the message’s subject…
Thanks
-Vincent
--
Thomas Mortagne On 6 May 2017, at 12:10, Vincent Massol
<vincent(a)massol.net> wrote:
Hi,
Feedback from user (see http://www.xwiki.org/xwiki/bin/view/Main/DownloadFormFeedback):
“
Hello! There is very lack simple data backup. The lack of a simple backup of all data
(via the web interface) greatly limits the use of Xwiki. Such a backup is available at
Confluence.
Another disadvantage is a complicated backup and a complicated installation.
“
I think that a first step to answer this would be to develop a new XAR format version
(v1.4 for example, see
http://extensions.xwiki.org/xwiki/bin/view/Extension/XAR%20Module%20Specifi…) that
adds support for saving/restoring the permanent directory.
WDYT?
Thanks
-Vincent