22 Aug
2010
22 Aug
'10
6:11 p.m.
On 08/21/2010 11:24 PM, Paul Libbrecht wrote:
I recently turned log4j's root category of my
xwiki to info and I get
floods of the following exceptions:
2010-08-21 22:21:00,381 INFO def.DefaultLoadEventListener - Error
performing load command
org.hibernate.ObjectNotFoundException: No row with the given
identifier exists: [com.xpn.xwiki.doc.XWikiDocument#2524421]
at org.hibernate.impl.SessionFactoryImpl
$1.handleEntityNotFound(SessionFactoryImpl.java:377)
at
org
.hibernate
.event.def.DefaultLoadEventListener.load(DefaultLoadEventListener.java:
145)
at
org
.hibernate
.event
.def
.DefaultLoadEventListener.proxyOrLoad(DefaultLoadEventListener.java:195)
at
org
.hibernate
.event
.def.DefaultLoadEventListener.onLoad(DefaultLoadEventListener.java:103)
at org.hibernate.impl.SessionImpl.fireLoad(SessionImpl.java:
878)
at org.hibernate.impl.SessionImpl.load(SessionImpl.java:784)
at
com
.xpn
.xwiki.store.XWikiHibernateStore.loadXWikiDoc(XWikiHibernateStore.java:
611)
this sounds dark and probably a performance eater (exceptions always
are even if not stacktraced). Can anyone suggest me a method to
identify how to avoid such errors or what they uncover?
thanks in advance
I guess this is the normal result when trying to load non-existing
documents. And XWiki tries to load a lot of such documents, when
checking rights or preferences.
First performance improvement possible would be to optimize the
loadXWikiDocument method to first check if the doc exists, with a
"select doc.id from XWikiDocument doc where doc.id like ?",
targetDoc.getId(), and checking if there's at least one result.
A second performance improvement would be to add more caches everywhere,
rights cache, preferences cache, document title cache...
--
Sergiu Dumitriu
http://purl.org/net/sergiu/