Include version and edition of neo4j database in health details

[bmscomp]

Actually heath indicator details for Neo4j returns the number of nodes witch makes one database hit

  neo4j: {
  status: "UP",
  details: {
      nodes: 0
    }
  }

Comparing to other database vendors, I found more useful to show technical details (version and edition) about the database rather then returning the number of nodes in the database

With this pull request the Neo4j heath details will be as follow

  neo4j: {
  status: "UP",
  details: {
      edition: "community",
      version: "4.0.0"
    }
  }

Notice that the new request will make 0 hits to the database, and I guess less time consuming then counting the total number of nodes

[snicoll]

Thanks for the PR

Notice that the new request will make 0 hits to the database,

I think that can be a problem as making a hit to the database is validating the connection is operating properly. Not doing so may lead to an UP indicator while the access to the database (or the database itself) is down.

paging @michael-simons for insights.

[michael-simons]

That’s a valuable change. I actually don’t like the original query at all as it goes to the node store.
The query here goes over the wire to the database, so the connection is verified. No issues on that side.

I’m unsure however since when Neo4j has that stored procedure and OGM still supports 3.2. Please make also sure it works on embedded.

For the alternate starter that uses bolt only and doesn’t bring in OGM, I’ll probably add the same information. Like it a lot.

For comparison here’s what we do over there
https://github.com/neo4j/neo4j-java-driver-spring-boot-starter/blob/master/neo4j-java-driver-spring-boot-autoconfigure/src/main/java/org/neo4j/driver/springframework/boot/actuate/Neo4jHealthIndicator.java#L99

[bmscomp]

Yes the updated CYPHER query works for version 3.2 and on embedded version of neo4j and of course 4.0.0 , is there any need to add an integration test for those versions

[michael-simons]

@snicoll Big thumbs up from my side.

Much less impact on the database while still verifying the connection and better info.

[snicoll]

@bmscomp thanks a lot for the PR.