Hi David and Ludovic,
I have finished implementing the second method proposed to achieve the
distributed search of XWiki.
In method I, the master node search the individual indexes each XWiki
Installation.
In method II, the master node maintains a global index of all the other
XWiki Installations and searches on it.
the code has been committed here
https://svn.xwiki.org/svnroot/xwiki/sandbox/plugins/distributedSearchMethod2
Implementation details of both method I and II are presented in detail @
http://dev.xwiki.org/xwiki/bin/view/Design/DistributedXWikiSearchEngine
---
Sai Krishna