Thank you Marek, I'll give it a try, I cleaned the repository without updating the conf a couple of hours ago and the issue haven't appeared yet, but as you say this may lead to issues in the future so why not.
Thanks 2013/3/28 Marek Šurek <marek_su...@yahoo.co.uk> > Hi, > as long as I understand the error and behaviour it causes (I experienced > this error few times before so I'm familiar), it can end with two > scenarios, but both are considered as blocker/critical bugs: > 1. You didn't recieve results which you should recieve (all data indicate > the query is correct but even though you don't get all results you should > get) > 2. As statistics are broken the query which should normally take 1sec now > runs e.g 20 minutes. > > I think the second option fits to you. When query is executed, it is > normally running and in some future it will give results, but as it needs > the much higher time to return results it blocks database(instead of taking > database resources for 1second it uses it for 20 minutes and therefore you > see such high CPU usage). The thing that you noticed this behaviour this > morning is just lucky concidence and sooner or later you will certainly > fall into trouble. > I think the statistics which are broken are always related to specific > predicates. As you didn't use the predicate which has broken statistics, > you didn't notice it. > > From my previous experience, disabling context-index + also set index > compression to -1 could solve some issues (but probably you'll have to > reload the database). It is certainly not cure, but it can help you to work > with application until the bug will be fixed. > Hope I explain it bit to you. Hope the fix will come soon. > > Best regards, > Marek > > > ------------------------------ > *From:* Stefano Parmesan <parme...@spaziodati.eu> > *To:* Marek <marek_su...@yahoo.co.uk> > *Cc:* "owlim-discussion@ontotext.com" <owlim-discussion@ontotext.com> > *Sent:* Thursday, 28 March 2013, 14:10 > *Subject:* Re: [Owlim-discussion] Owlim-SE not responding with high CPU > load > > $ grep "ERROR IN PREDICATE STATISTICS" catalina.out | wc -l > 32368 > (since the 25th) > > Apparently the last error is of yesterday afternoon, but we experienced > such problems this morning as well, I can't say if they are related. > > Thanks and regards > > > 2013/3/28 Marek <marek_su...@yahoo.co.uk> > > we experienced very similar behaviour with nearly the same usecase. i > reported one bug which was in our case temporarily solved by turning off > context index. recently i found other very similar issue, which is not > reportwd yet as i cant figure out the cause. look pls into catalina.out > whether there is not log "error in predicate statistics" which appears in > both mentioned issues. maybe we hit the same problem. > best regards, > marek > ------------------------------ > From: Stefano Parmesan <parme...@spaziodati.eu> > Sent: 28.3.2013 12:09 > To: owlim-discussion@ontotext.com > Subject: [Owlim-discussion] Owlim-SE not responding with high CPU load > > Hi everybody, > > We are evaluating Owlim-SE 5.3.5849 but we are encountering some issues: > > Our test repository contains around 1 million triples (around 100 of those > are owl:sameAs) and have concurrent applications both inserting and > querying (through sesame-console and the sparql endpoint provided by the > sesame-workbench). The machine is a 12-core 64GB ram debian machine. > Everything worked fine as of today, when something happened while we were > submitting a high load to the sparql endpoint. Since then, tomcat7 uses > from 200% to 650% of cpu, and the sparql endpoint does not respond with > even simple queries. > > We tried restarting tomcat7 multiple times, but as soon as it comes back > the CPU usage increases again and there's no way to do anything (through > both sesame-workbench and sesame-console). > > Could this be due to some misconfiguration? Is this a known issue? How can > we know what's really happening (apart from > checking .aduna/openrdf-sesame/logs)? > > We could clear the repository and start from scratch, but as we are > evaluating Owlim for production usage we need to find out what's the issue > to better understand if it fits our needs. > > -- > Dott. Stefano Parmesan > Web Developer ~ SpazioDati s.r.l. > Via del Brennero, 52 – 38122 Trento – Italy > > > > > -- > Dott. Stefano Parmesan > Web Developer ~ SpazioDati s.r.l. > Via del Brennero, 52 – 38122 Trento – Italy > > > -- Dott. Stefano Parmesan Web Developer ~ SpazioDati s.r.l. Via del Brennero, 52 – 38122 Trento – Italy
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