SPARQL Insert node encryption issue(s) with endpoint

Hi All,

trying to upload data into a local Graphdb endpoint (no https), and getting the following issue from time to time as it is uploading data via a generic loop construct

ERROR SPARQL Insert 3:540 Unable to clone input data at port 1 (Semantic Web Connection): javax.crypto.IllegalBlockSizeException: Input length must be multiple of 8 when decrypting with padded cipher

or sometimes

ERROR SPARQL Insert 3:538 Unable to clone input data at port 1 (Semantic Web Connection): javax.crypto.BadPaddingException: Given final block not properly padded. Such issues can arise if a bad key is used during decryption.

simply rerunning the node solves it, but it breaks the loop execution.

→ using graphdb-10.1.4
→ using KNIME Semantic Web - 4.5.0.v202107011903

also, would there be a way to bulk upload via the SPARQL insert node ?

Kind regards,


Apologies to bump this one up, but wanted to make sure if there was something wrong in the node implementation, or whether there was something wrong with my set-up.

The breaking of the loop iteration is quite annoying as i would need to get large volumes into the SPARQL endpoint.

Thank you so much!


Hello @hermyknime ,
is it possible that some entries in the graphdb are not properly encrypted? Does it happen with the same entries every time?
We are working on updating the Semantic Web library that we use in the nodes and will release a new version of the extension with the 4.7.2 release. Maybe this will solve the problem. However I have no date as of now when 4.7.2 will be available. If you want to you can try the new version of the semantic web extension with the version 5 preview.
Regarding the bulk upload, I have created a feature request (internal number AP-20241) to investigate it.

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thx @tobias.koetter for your response and view on the next release candidate!

Not sure what you mean when you say “some entries in the graphdb are not properly encrypted”?

I’m using the standard settings of Ontotext Graphdb, i don’t think there is standard encryption of data in the database. It feels that there might be some encryption over the wire, where the packages sent are not correctly formed (padded).

I’m not able to pin point it to a specific value. When I simply re-run the node, it get’s solved, so I don’t think it is a specific value causing the error - in a predictable way.

I’ll look forward to the next release and give it a spin!



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