CODEWITHSUNDEEP
gremlinamazon-neptune
Avner Levy
Avner Levy

Reputation: 6751

Debugging gremlin problems with AWS Neptune

I've sent a gremlin statement which fails with the following error:

{"code":"InternalFailureException","requestId":"d924c667-2c48-4a7e-a288-6f23bac6283a","detailedMessage":"null: .property(Cardinality, , String)"} (599)

I've enabled audit logs on the cluster side but there aren't any indications for any errors there although I see the request.
Are there any technics to debug such problems with AWS Neptune?

Since the gremlin is built dynamically and builds complicated graphs with thousands of operations, I'm looking for some way to understand better where the error is.
In one case it turned out the payload was too big and in another, the gremlin bytecode failed although it worked great on the local Tinkerpop Server.
But with the generic internal failure exception it is very hard to pinpoint the issues.

I'm using the Node.js gremlin package (3.5.0).

Upvotes: 1

Views: 1239

Answers (1)

Kelvin Lawrence
Kelvin Lawrence

Reputation: 14391

Thanks for the clarifications. As a side note, Neptune is not yet at the 3.5.0 TinkerPop level so there is always the possibility of mismatches between client and server. The audit log only shows the query received. It does not reflect the results of running the query. When I am debugging issues like this one, I often create a text version of the query (the node client has a translator that can do that for you) and use the Neptune REST API to first of all check the /explain plan - you can also generate that from the Neptune notebooks using %%gremlin explain. If nothing obvious shows up in the explain plan I usually try to run the text version of the query just to see if anything shows up - to rule out the client driver. I also sometimes run my query against a TinkerGraph just to see if the issue is as simple as Neptune not returning the best error message it could. If the text query should work, changing the Node.js Gremlin client driver to 3.4.11 is worth trying.

UPDATED to add a link to the documentation on Gremlin translators.

https://tinkerpop.apache.org/docs/current/reference/#translators

Upvotes: 1

Related Questions