This is the release notes for XWiki Commons, XWiki Rendering, XWiki Platform and XWiki Enterprise. They share the same release notes as they are released together and have the same version.

This is a bugfix release that improves the user avatar image quality and reduces the memory footprint when importing wiki pages with attachments.

New and Noteworthy (since XWiki 8.4.3)

Full list of issues fixed and Dashboard for 8.4.4.

For Users

Improved avatar image quality

 
XWiki supports server-side image resizing since version 2.5 but the quality of the scaled images was poor up until now. Starting with this version we're using the Thumbnailator library which leads to better image quality. This is most noticeable in the case of the user avatars.

For Admins

• Attachments are not loaded in memory anymore when imported: The XAR input filter used to load an entire attachment in memory before sending it to the Instance output. It's now stored in a temporary file before being sent as an InputStream.

For Developers

No changes!

All Changes

Translations

The following translations have been updated: 

• French

Tested Browsers & Databases

Here is the list of browsers we support and how they have been tested for this release:

	Browser	Test Result
	Google Chrome 55	Jira Tickets Marked as Fixed in the Release Notes + New features
	Mozilla Firefox	Not Tested
	Internet Explorer 10	Not Tested
	Internet Explorer 11	Not Tested

Here is the list of databases we support and how they have been tested for this release:

	Database	Test Result
	HyperSQL 2.3.4	Jira Tickets Marked as Fixed in the Release Notes
	MySQL	Not Tested
	Oracle	Not Tested
	PostgreSQL 9.6.1	New features

Performances tests compared to 7.4.5

Summary

Jetty startup takes longer mostly because of:

• Let's Encrypt certificate registration (which recreate the certificate store). This module is not embedded anymore in 9.0.
• Full loading of core extensions. Small price to pay to have a much more reliable core extension index (in most cases there is no guessed or missing core extension anymore). The size of the wiki has no impact on time spent (the number of core extensions does not change).

The skin is a lot slower than in 7.4.5.

A lot of work has been done to improve Solr UI display (a bit less obvious with the slowness of the skin).

The memory has been reduced a lot compared to 8.3 thanks to optimization in the way to create Extension instances to reduce a lot the duplications (only one instances kept for identical instances of Version, ExtensionDependency, etc.). The difference is even more important in very big wikis like http://myxwiki.org which contains a huge number of installed extensions cached in memory.

"similar": difference is lower than 10%
"slightly": difference is lower than 20%

Speed

Memory

More details on performance comparison on single wiki between 8.4.4 and 7.4.5.

Known issues

• Bugs we know about

Backward Compatibility and Migration Notes

General Notes

When upgrading make sure you compare your xwiki.cfg, xwiki.properties and web.xml files with the newest version since some configuration parameters may have been modified or added. Note that you should add xwiki.store.migration=1 so that XWiki will attempt to automatically migrate your current database to the new schema. Make sure you backup your Database before doing anything.

API Breakages

No API has been broken since XWiki 8.4.3!

Credits

The following people have contributed code to this release (sorted alphabetically):

• Ecaterina Moraru (Valica)
• Marius Dumitru Florea
• Thomas Mortagne
• Vincent Massol