I think we should wait for Andy here with further input as he's the
persons who basically designed and implemented all the fancy stuff and
knows better advice for sure.
@Andy Did you read the whole discussion and can you verify that it's
expected behavior that lot's of daily updates lead to such a big growth
of the node table files?
On 07.07.22 10:53, Bartalus Gáspár wrote:
Hi Lorenz,
Would you recommend using tdb1 instead of tdb2 for our use case? What would be
the differences?
We are using fuseki 4.5.0 btw.
Gaspar
On 6 Jul 2022, at 14:39, Bartalus Gáspár
<[email protected]> wrote:
Hi,
Most of the updates are DELETE/INSERT queries, i.e
DELETE {?s ?p ?oldValue}
INSERT {?s ?p ?newValue}
WHERE {
OPTIONAL {?s ?p ?oldValue}
#derive ?newValue from somewhere
}
We also have some separate DELETE queries and INSERT queries.
I’ve tried HTTP POST /$/compact/db_name and as a result the files are getting
back to normal size. However, as far as I can tell the old files are also kept.
This is the folder structure I see:
- databases/db_name/Data-0001 - with the old large files
- databases/db_name/Data-0002 - presumably the result of the compact operation
with normal file sizes.
Is there also some operation (http or cli) that would keep only one (the
latest) data folder, i.e. delete the old files from Data-0001?
Gaspar
On 6 Jul 2022, at 12:52, Lorenz Buehmann <[email protected]>
wrote:
Ok, interesting
so
we have
- 150k triples, rather small dataset
- loaded into 10MB node table files
- 10 updates every 5s
- which makes up to 24 * 60 * 60 / 5 * 10 ~ 200k updates per day
- and leads to 10GB node table files
Can you share the shape of those update queries?
After doing a "compact" operation, the files are getting back to "normal" size?
On 06.07.22 10:36, Bartalus Gáspár wrote:
Hi Lorenz,
Thanks for quick feedback and clarification on lucene indexes.
Here are my answers to your questions:
- We are uploading 7 ttl files to our dataset, where 1 is larger 6Mb, the
others are below 200Kb.
- The overall number of triples after data upload is ~150000.
- We have around 10 SPARQL UPDATE queries that are executed on a regular and
frequent basis, i.e. every 5 seconds. We also have 5 such queries that are
executed each minute. But most of the time they do not produce any outcome,
i.e. the dataset is not altered, and when they do, there are just a couple of
triples that are added to the dataset.
- These *.dat files start from ~10Mb in size, and after a day or so some of
them grow to ~10Gb.
We have ~300 blank nodes, and ~half of the triples have a literal in the object
position, so ~75000.
Best regards,
Gaspar
On 6 Jul 2022, at 10:55, Lorenz Buehmann <[email protected]>
wrote:
Hi and welcome Gaspar.
Those files do contain the node tables.
A Lucene index is never computed by default and would be contained in Lucene
specific index files.
Can you give some details about the
- size of the files
- the number of triples
- the number triples added/removed/changed
- the frequency of updates
- how much the files grow
- what kind of data you insert? Lots of blank nodes? Or literals?
Also, did you try a compact operation during time?
Lorenz
On 06.07.22 09:40, Bartalus Gáspár wrote:
Hi Jena support team,
We are experiencing an issue with Jena Fuseki databases. In the databases
folder we see some files called SPO.dat, OSP.dat, etc., and the size of these
files are growing quickly. From our understanding these files are containing
the Lucene indexes. We would have two questions:
1. Why are these files growing rapidly, although the underlying data (triples)
are not being changed, or only slightly changed?
2. Can we disable indexing easily, since we are not using full text searches in
our SPARQL queries?
Our usage of Jena Fuseki:
* Start the server with `fuseki-server —port 3030`
* Create databases with HTTP POST to
`/$/datasets?state=active&dbType=tdb2&dbName=db_name`
* Upload ttl files with HTTP POST to /db_name/data
Thanks in advance for your feedback, and if you’d require more input from our
side, please let me know.
Best regards,
Gaspar Bartalus
