Sebastien Fieux wrote:

I had to count the number of connections to the database needed by XWiki to set the appropriate number in the DB configuration. I saw (http://jira.xwiki.org/jira/browse/XWIKI-2332 ) that there is one session factory for every Hibernate Store. After a quick look on the web I understood that a session factory provides one session at a time (basically: if the session is open, then re-use the same session), and the session owns the connexions pool, set to 1 by hibernate.cfg.xml. So I assume I should have one opened connexion for every Hibernate store.

That is true if there are no parallel requests. If there are two or more requests at the same time, they cannot share the same connection, so they will block until the connection becomes available. It is better to use more connections than the minimum; the right number of connections depends a lot on the server load, the available memory, the performance of the DBMS, and a sysadmin should be able to decide what is the best value here.

According to the initXWiki method from the com.xpn.xwiki.XWiki class, there is 7 stores : - Main store - Attachments store - Versioning store - Attachment versioning store - Recycle bin store - Attachments recycle bin store - Migration store (updating the database after XWiki update).

So my question is : Am I right ? Are 7 connexions really enough ? It seems to work, although I didn't tested everything more than seeing pages. Any answer from someone having a better knowledge of XWiki's internal functionment and/or Hibernate would be welcome.

All that waiting for the 1.5 version which should allow a shared factory between every store...

-- Sergiu Dumitriu http://purl.org/net/sergiu/