¡resource not found!

[syphax-bouazzouni]

Hello,

I have recently found that in many of our SPARQL requests, 4store return values that look like this ¡resource dad5d4cb7c7b9e5e not found! instead of the correct value.

To reproduce

4s-backend-destroy ontoportal_kb
4s-backend-setup --segments 4 ontoportal_kb
4s-backend ontoportal_kb

4s-update ontoportal_kb "DELETE {?s ?p ?o } WHERE { ?s ?p ?o}" #clear the triple store

4s-update ontoportal_kb "INSERT DATA {
                         	GRAPH <http://goo.org/default/Project> {
                         		<http://goo.org/default/project/Goo> <http://www.w3.org/1999/02/22-rdf-syntax-ns#type> <http://goo.org/default/Project> .
                         		<http://goo.org/default/project/Goo> <http://goo.org/default/name> \"Goo\" .
                         	}
                         }" # insert a project

4s-query ontoportal_kb "SELECT DISTINCT ?id ?attributeProperty  ?attributeObject ?inverseAttributeObject
                        FROM <http://goo.org/default/Project>
                        FROM <http://goo.org/default/Task>
                        WHERE {
                        	?id a <http://goo.org/default/Project> .
                        	OPTIONAL { ?id ?attributeProperty ?attributeObject .  }
                        	OPTIONAL { ?inverseAttributeObject ?attributeProperty ?id .  }
                          FILTER(?attributeProperty = <http://goo.org/default/project> || ?attributeProperty = <http://goo.org/default/name>)
                        }" # list the projects with their tasks (inverse attribute)

What we should have as a result

id	attributeProperty	attributeObject	inverseAttributeObject
http://goo.org/default/project/Goo	http://goo.org/default/name	Goo

What we actually have

id	attributeProperty	attributeObject	inverseAttributeObject
http://goo.org/default/project/Goo	¡resource dad5d4cb7c7b9e5e not found!
http://goo.org/default/project/Goo	http://goo.org/default/name	Goo

And in the logs we have the following

➜  4store-original git:(master) ✗ 4s-backend -D ontoportal_kb                
Jul 14 00:20:03  4store[95464] <Info>: 4s-server.c:472 kb=ontoportal_kb runtime information file created
Jul 14 00:20:03  4store[95464] <Info>: 4s-server.c:582 4store backend v1.1.6-NCBO-SNAPSHOT-1 for kb ontoportal_kb on port 6734 (1 fds)
Jul 14 00:20:22  4store[95660] <Warning>: rhash.c:713 resource dad5d4cb7c7b9e5e not found in § 0x1ee70-0x1ee8f of /var/lib/4store/ontoportal_kb/0002/res.rhash
Jul 14 00:26:40  4store[99571] <Warning>: rhash.c:713 resource dad5d4cb7c7b9e5e not found in § 0x1ee70-0x1ee8f of /var/lib/4store/ontoportal_kb/0000/res.rhash

Do you have any idea how to fix it ? (it is maybe related to this #120)

[swh]

I don't think it's related to #120.

I think that when the resource table are create, we preload them with a bunch of common URIs like http://www.w3.org/1999/02/22-rdf-syntax-ns#type. I suspect that the DELETE is wiping them out.

Unfortunately it's been a very long time since I looked at this code, so I'm not sure I could find the error.

Can you confirm it doesn't happen if you delete the KB and recreate on the command line?

[syphax-bouazzouni]

Thanks for your quick reply,

For the deleting and recreating part of the KB , the three first commands in my to reproduce section ( 4s-backend-destroy ontoportal_kb && 4s-backend-setup --segments 4 ontoportal_kb && 4s-backend ontoportal_kb') are are supposed to do that I think.

But I confirm that even with that the issue is still there.

I may add that this issue (¡resource not found!) occurs only for the predicate (till now).
And we can also have this situation (but it is hard to reproduce)

id	attributeProperty	attributeObject	inverseAttributeObject
http://goo.org/default/project/Goo	¡resource dad5d4cb7c7b9e5e not found!		http://goo.org/default/task/task_0
http://goo.org/default/project/Goo	http://goo.org/default/name	Goo