问题
We have a Neo4J 2.1.3 database and we have a uniqueness constraint that was created as follows:
CREATE CONSTRAINT ON (segment:SEGMENT) ASSERT segment.segmentId IS UNIQUE
When we test this from the browser, it works fine in detecting violations, e.g:
CREATE (n:SEGMENT {name : "duplicate", segmentId : 110484}) RETURN n
results in
Node 589 already exists with label SEGMENT and property "segmentId"=[110484]
Neo.ClientError.Schema.ConstraintViolation
which is fine.
We have a load tester setup with 3 machines and multiple threads per box using Cypher over REST talking to Neo4J and using the transactional endpoints to do creates similar to above (but of course many more properties relevant to our app), and always writing to the Neo4J master in an HA setup.
We can reliably reproduce in that setup multiple violations of the uniqueness constraint that are NOT caught by Neo4J, they execute without error and in the resulting db we can see multiple nodes with the SEGMENT label and the same value for the segmentId property (we are intentionally generating duplicate segmentId values for our test).
Anyone else run into the same issue? Is this a Neo4J bug?
Thanks.
来源：https://stackoverflow.com/questions/25878581/neo4j-2-1-3-uniqueness-constraint-being-violated-is-this-a-bug