Release Notes for XWiki 8.4.4

Last modified by Vincent Massol on 2017/06/09

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


The following translations have been updated: 

Tested Browsers & Databases

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

BrowserTest Result
Chrome30.pngGoogle Chrome 55Jira Tickets Marked as Fixed in the Release Notes + New features
Firefox30.pngMozilla FirefoxNot Tested
IE30.pngInternet Explorer 10Not Tested
IE30.pngInternet Explorer 11Not Tested

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

DatabaseTest Result
hypersql.pngHyperSQL 2.3.4Jira Tickets Marked as Fixed in the Release Notes
mysql.pngMySQLNot Tested
oracle.pngOracleNot Tested
postgresql.pngPostgreSQL 9.6.1New features 

Performances tests compared to 7.4.5


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 which contains a huge number of installed extensions cached in memory.

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

Note that most of the speed related values are an average of very moving results, a lot of things is happening during a HTTP request and it's far from stable duration (that's why 10% may sounds a lot for something called "similar" but the variable can go up and down around 5% sometimes so 10% average is really not that much of a clear win). Dumbbench based tests are executed several times and the lowest result is selected. 


Jetty startup+25%
First accessnot existing page without UIsimilar
not existing page with UI+36%
Reloadnot existing page without UIsimilar
not existing page with UI+35%
empty page without UIsimilar
empty page with UI+22%
Main.WebHome without UI/5
Main.WebHome with UI-21%
SOLRFull SOLR reindexsimilar
SOLR sync when index is emptysimilar
SOLR sync when there is nothing to dosimilar
Result of search finding lots of results-23%
Result of search finding one result-32%
RenderingPage with 1000 macros without UI-15%
Page with 1000 html macros without UI-17%


Heap Memory after jetty startupsimilar
Heap Memory after full SOLR indexsimilar

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

Known issues

Backward Compatibility and Migration Notes

General Notes

When upgrading make sure you compare your xwiki.cfg, and web.xml files with the newest version since some configuration parameters may have been modified or added. Note that you should add 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!


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

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

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