Unexplained ConstraintViolationException with AWS Neptune

Question

I get this constraintViolationException with AWS Neptune when I tried to create a bunch of edges. The problem is that it does not tell which edge already exists. I add roughly 50 edges at once using script via java gremlin-driver.

Has anyone came across this kind of scenario ?

org.apache.tinkerpop.gremlin.driver.exception.ResponseException: {"requestId":"c1e55266-6fa9-44f6-91b3-74f08d227ffd","code":"ConstraintViolationException","detailedMessage":"Edge with id already exists: "}

score 0 · Answer 1 · answered Jan 31 '22 at 18:36

0

The database supports ACID transaction writes. So if your query attempts to create multiple edges, with user provided IDs, which have to be unique, the whole transaction will either work (and commit) or fail (and rollback). This error, as you noticed, is because at least one of the IDs you provided is already in use.

You have a couple of options.

Change the query to more of a "create if not exist" pattern.
Run a query to find out which of the IDs already exists, prior to trying to add them all.

In an upcoming release of Apache TinkerPop we are planning to add a merge step that will make this type of task easier. Until that time, one of the two options above is the way to go in general.

answered Jan 31 '22 at 18:36

Kelvin Lawrence

14,674
2
16
38

I follow the same startegy, check for edges and then try creating. But Neptune sometimes randomly behaves otherwise. When there is a genuine duplication relevant edge ids are returned back in response, but some times edgeid does not come back. – samairtimer Feb 02 '22 at 10:59
Can you add an example of the query you are using to the question? – Kelvin Lawrence Feb 02 '22 at 12:31
Since the query is large added to paste bin https://pastebin.com/8pepp91e – samairtimer Feb 03 '22 at 04:40
We add 100 Edges and 100 Vertices at a time. – samairtimer Feb 03 '22 at 04:41

Unexplained ConstraintViolationException with AWS Neptune

1 Answers1