3 replies

JanusGraph AdjacentVertex Optimization

Hiya,
I'm wondering if anyone has any advice on how to inspect the provider-side optimizations being applied to my gremlin code by janus graph.
Currently when I call

explain

explain

I get the following output.

Original Traversal   [GraphStep(vertex,[]), HasStep([plabel.eq(Person)])@[a], VertexStep(OUT,vert
                        ex)@[b], VertexStep(OUT,vertex), WherePredicateStep(null,eq(a)), CountGlobal
                        Step, ProjectStep([COUNT(*)],[identity])]

RemoteStrategy [D]   [RemoteStep(DriverServerConnection-localhost/127.0.0.1:8182 [graph=g])]

Final Traversal      [RemoteStep(DriverServerConnection-localhost/127.0.0.1:8182 [graph=g])]

Original Traversal   [GraphStep(vertex,[]), HasStep([plabel.eq(Person)])@[a], VertexStep(OUT,vert
                        ex)@[b], VertexStep(OUT,vertex), WherePredicateStep(null,eq(a)), CountGlobal
                        Step, ProjectStep([COUNT(*)],[identity])]

RemoteStrategy [D]   [RemoteStep(DriverServerConnection-localhost/127.0.0.1:8182 [graph=g])]

Final Traversal      [RemoteStep(DriverServerConnection-localhost/127.0.0.1:8182 [graph=g])]

Which isn't very helpful of course.

Secondly, I'm trying to use explain to figure out whether it's possible to have JanusGraph apply its AdjacentVertex optimisation (can find related code around here) when the vertex is stored dynamically using

as

as

rather then being a id known ahead of time.
i.e. do we get adjacency behaviour from the query

g.V().as("a").out().as("b").out().where(P.eq("a"))

g.V().as("a").out().as("b").out().where(P.eq("a"))

or is it possible to get the behaviour for something similar without using two queries.
Thanks in advance.

Solution

TinkerPop applies all optimization strategies to all queries (including JanusGraph internal optimizations). However, JanusGraph skips some of the optimizations as it sees necessary. We don't currently store information if the optimization strategy modified any part of the query or was simply skipped (potential feature request). Thus, the way I would test if the optimization strategy actually makes any changes or not is to debug the query with the breaking point placed in the necessary optimization strategy.
I.e. in your case I would place a breaking point here: https://github.com/JanusGraph/janusgraph/blob/c9576890b5e9dc48676ccc16a58552b8a665e5f0/janusgraph-core/src/main/java/org/janusgraph/graphdb/tinkerpop/optimize/strategy/AdjacentVertexOptimizerStrategy.java#L58C13-L58C28
If this part is triggered during your query execution - optimization works in this case.

GitHub

janusgraph/janusgraph-core/src/main/java/org/janusgraph/graphdb/tin...

JanusGraph: an open-source, distributed graph database - JanusGraph/janusgraph

Jump to solution

JanusGraph AdjacentVertex Optimization

Hiya,
I'm wondering if anyone has any advice on how to inspect the provider-side optimizations being applied to my gremlin code by janus graph.
Currently when I call

explain

explain

I get the following output.

Original Traversal   [GraphStep(vertex,[]), HasStep([plabel.eq(Person)])@[a], VertexStep(OUT,vert
                        ex)@[b], VertexStep(OUT,vertex), WherePredicateStep(null,eq(a)), CountGlobal
                        Step, ProjectStep([COUNT(*)],[identity])]

RemoteStrategy [D]   [RemoteStep(DriverServerConnection-localhost/127.0.0.1:8182 [graph=g])]

Final Traversal      [RemoteStep(DriverServerConnection-localhost/127.0.0.1:8182 [graph=g])]

Original Traversal   [GraphStep(vertex,[]), HasStep([plabel.eq(Person)])@[a], VertexStep(OUT,vert
                        ex)@[b], VertexStep(OUT,vertex), WherePredicateStep(null,eq(a)), CountGlobal
                        Step, ProjectStep([COUNT(*)],[identity])]

RemoteStrategy [D]   [RemoteStep(DriverServerConnection-localhost/127.0.0.1:8182 [graph=g])]

Final Traversal      [RemoteStep(DriverServerConnection-localhost/127.0.0.1:8182 [graph=g])]

as

as

rather then being a id known ahead of time.
i.e. do we get adjacency behaviour from the query

g.V().as("a").out().as("b").out().where(P.eq("a"))

g.V().as("a").out().as("b").out().where(P.eq("a"))

or is it possible to get the behaviour for something similar without using two queries.
Thanks in advance.

Solution

GitHub

janusgraph/janusgraph-core/src/main/java/org/janusgraph/graphdb/tin...

JanusGraph: an open-source, distributed graph database - JanusGraph/janusgraph

Jump to solution

JanusGraph AdjacentVertex Optimization

JanusGraph AdjacentVertex Optimization

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