On 13/07/15 21:31, Andy Seaborne wrote:
Hi Ric,

Could you please try Fuseki 1.1.2 or Fuseki 2.0.0?

How many datasets does the server host?

1.0.1 was Jan 2014 and IIRC this area has changed, especially DELETE of
a graph with the Graph Store Protocol.  However, if this is just due to
transaction overheads (it's not immediately clear it is or is not), then
DELETE {} WHERE { SELECT {...} LIMIT } is the way to go for an immediate
solution.

TDB1 (i.e. the Jena code) is a bit memory hungry for transactions.

TDB2 is not memory bound but it isn't in the Jena codebase.  It has been
tested with 100 million triple loads in a single Fuseki2 upload.

See
   http://www.sparql.org/validate/update

That's the service point.

http://www.sparql.org/update-validator.html

is the HTML formm.

for checking syntax.

     Andy

On 13/07/15 18:59, Ric Roberts wrote:
Hi. I’m having problems deleting a moderately large graph from a
jena-fuseki-1.0.1 database.

The graph contains approximately 60 million triples, and the database
contains about 70 million triples in total.

I’ve started Fuseki with 16G Heap. (JVM_ARGS=${JVM_ARGS:—Xmx16000M}).
The server has 32G RAM.

When I issue the DELETE command over http, I see this in the fuseki log:

16:12:03 INFO  [24] DELETE
http://127.0.0.1:3030/stagingdb/data?graph=http://example.com/graph
<http://127.0.0.1:3030/stagingdb/data?graph=http://example.com/graph>
17:10:40 WARN  [24] RC = 500 : Java heap space
17:10:40 INFO  [24] 500 Java heap space (3,517.614 s)

i.e. it takes about an hour, and then 500s with an error about heap
space.

I’ve also tried DROP and CLEAR SPARQL update statements but they
timeout with our default endpoint timeout of 30s.

I’ve also tried deleting 1000 triples at a time, from the graph by
issuing a sparql update statement like this:

DELETE {
  GRAPH <http://example.com/graph <http://example.com/graph>>
    { ?s ?p ?o }
}
WHERE {
   GRAPH <http://example.com/graph <http://example.com/graph>>
     { ?s ?p ?o }
}
LIMIT 1000

… but this times out too (which surprised me, as I only asked it to
find and DELETE 1000 triples).

What is the recommended way to delete this graph - I need to replace
its contents fairly urgently on a production system. We loaded it by
loading 10,000 triples at a time, which worked fine, but I’m having
trouble deleting its current contents first.

Any pointers appreciated.
Thanks, Ric.


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