I think that the second pattern "create a dataset object on the thread", or rather in my case "create a dataset object for one HTTP request" is worth trying.
And I want to know why the doc seems to prefer the first pattern. 2016-02-03 18:30 GMT+01:00 A. Soroka <aj...@virginia.edu>: > > On Feb 3, 2016, at 5:13 AM, Jean-Marc Vanel <jeanmarc.va...@gmail.com> > wrote: > > > > In the documentation, > > > > > https://jena.apache.org/documentation/tdb/tdb_transactions.html#multi-threaded-use > > > > it is not clear which use pattern is preferred and the reason why. > > The first pattern shows a single dataset object being shared between > threads, each of which operates a transaction against that object, and the > second pattern is introduced with "or create a dataset object on the thread > (the case above is preferred):”. > > As to why, I am not familiar enough with TDB to be sure, but there is a > comment on the second pattern "Each thread has a separate dataset object; > these safely share the same storage but have independent transactions.” > that would seem to indicate that the second pattern is vulnerable to having > conflicts between transactions opened against the two different dataset > objects. > > --- > A. Soroka > The University of Virginia Library > > > > On Feb 3, 2016, at 5:13 AM, Jean-Marc Vanel <jeanmarc.va...@gmail.com> > wrote: > > > > I have a repeating memory leak in TDB in my web application ( > > > https://github.com/jmvanel/semantic_forms/blob/master/scala/forms_play/README.md > > ). > > It is caching RDF documents from internet, typically dbpedia ressources. > > > > It is not the use case described in "Fuseki/TDB memory leak for > concurrent > > updates/queries" https://issues.apache.org/jira/browse/JENA-689 , as the > > journal is empty after crash . > > > > A single Dataset object is used for the duration of the application, and > I > > suspect this is the root cause. > > In the documentation, > > > > > https://jena.apache.org/documentation/tdb/tdb_transactions.html#multi-threaded-use > > > > it is not clear which use pattern is preferred and the reason why. > > > > You someone confirm that keeping a single Dataset object for the duration > > of the application is bad ? > > -- Jean-Marc Vanel Déductions SARL - Consulting, services, training, Rule-based programming, Semantic Web http://deductions-software.com/ +33 (0)6 89 16 29 52 Twitter: @jmvanel , @jmvanel_fr ; chat: irc://irc.freenode.net#eulergui
