Similar Gremlin Queries Written in Different Ways Have Performance Differences - graph-databases

Question

I have two gremlin traversal queries pretty much doing the same thing, each looks up a vertex with ID and upserts a new node with an edge to the new node.
I tried with this first because this looked cleaner:
g.V('22b515e0-dbefb359-10f3-71ff13527bb2').sideEffect(__.outE().drop())\
.addE('someedge').to(__.V().hasLabel('SomeLabel').has('name', \
'SomeName').sideEffect(__.properties().drop()).property('name123', \
'SomeName123')).next()
This query takes around 8 seconds every time it executes.
As a measure to fix the above issue, I tried changing the traversal to this and the response time is in milliseconds:
g.V().hasLabel('SomeLabel').has('name', \
'SomeName').sideEffect(__.properties().drop()).property('name123', \
'SomeName123').as_('X').V('22b515e0-dbef-b359-10f3-71ff13527bb2')\
.sideEffect(__.outE().drop()).addE('some \
edge').to(__.select('X')).next()
But, when I lookup using ID directly (In method - 1), even with this the response time is in milliseconds.
g.V('22b515e0-dbef-b359-10f3-71ff13527bb2').sideEffect(__.outE().drop())\
.addE('someedge').to(__.V('8b66cab2-3b1c-41c9-9acb-296dda3c9139')\
.sideEffect(__.properties().drop()).property('name123', \
'SomeName123')).next()
Here are some .profile() metrics which shows execution times.
For 1:
{'dur': 8823.148244,
'metrics': [{'dur': 0.336926,
'counts': {'traverserCount': 1, 'elementCount': 1},
'name': 'NeptuneGraphQueryStep(Vertex)',
'annotations': {'percentDur': 0.003818659628994895},
'id': '6.0.0()'},
{'dur': 1.882282,
'counts': {'traverserCount': 1, 'elementCount': 1},
'name': 'TraversalSideEffectStep([VertexStep(OUT,edge), ProfileStep, DropStep, ProfileStep])',
'annotations': {'percentDur': 0.02133345091736396},
'id': '1.0.0()',
'metrics': [{'dur': 0.275912,
'counts': {'traverserCount': 11, 'elementCount': 11},
'name': 'VertexStep(OUT,edge)',
'id': '0.1.0(1.0.0())'},
{'dur': 1.569401,
'counts': {},
'name': 'DropStep',
'id': '1.1.0(1.0.0())'}]},
{'dur': 0.115423,
'counts': {'traverserCount': 1, 'elementCount': 1},
'name': 'NoOpBarrierStep',
'annotations': {'percentDur': 0.0013081838455847213},
'id': '5.0.0()'},
{'dur': 8820.813613,
'counts': {'traverserCount': 1, 'elementCount': 1},
'name': 'AddEdgeStep({~to=[[GraphStep(vertex,[]), ProfileStep, NeptuneHasStep([~label.eq(SomeLabel), name.eq(SomeName)]), ProfileStep, TraversalSideEffectStep([PropertiesStep(property), ProfileStep, DropStep, ProfileStep]), ProfileStep, NoOpBarrierStep, ProfileStep, AddPropertyStep({value=[SomeName123], key=[name123]}), ProfileStep]], label=[some edge]})',
'annotations': {'percentDur': 99.97353970560806},
'id': '2.0.0()',
'metrics': [{'dur': 1346.058324,
'counts': {'traverserCount': 373732, 'elementCount': 373732},
'name': 'GraphStep(vertex,[])',
'id': '0.1.0(2.0.0())'},
{'dur': 7473.661772,
'counts': {'traverserCount': 1, 'elementCount': 1},
'name': 'NeptuneHasStep([~label.eq(SomeLabel), name.eq(SomeName)])',
'id': '5.1.0(2.0.0())'},
{'dur': 0.283139,
'counts': {'traverserCount': 1, 'elementCount': 1},
'name': 'TraversalSideEffectStep([PropertiesStep(property), ProfileStep, DropStep, ProfileStep])',
'id': '2.1.0(2.0.0())',
'metrics': [{'dur': 0.096149,
'counts': {'traverserCount': 1, 'elementCount': 1},
'name': 'PropertiesStep(property)',
'id': '0.2.0(2.1.0(2.0.0()))'},
{'dur': 0.149241,
'counts': {},
'name': 'DropStep',
'id': '1.2.0(2.1.0(2.0.0()))'}]},
{'dur': 0.046801,
'counts': {'traverserCount': 1, 'elementCount': 1},
'name': 'NoOpBarrierStep',
'id': '4.1.0(2.0.0())'},
{'dur': 0.306436,
'counts': {'traverserCount': 1, 'elementCount': 1},
'name': 'AddPropertyStep({value=[SomeName123], key=[name123]})',
'id': '3.1.0(2.0.0())'}]}]}
For 2:
{'dur': 5.596631,
'metrics': [{'dur': 0.510122,
'counts': {'traverserCount': 1, 'elementCount': 1},
'name': 'NeptuneGraphQueryStep(Vertex)',
'annotations': {'percentDur': 9.114804960341319},
'id': '11.0.0()'},
{'dur': 0.462721,
'counts': {'traverserCount': 1, 'elementCount': 1},
'name': 'TraversalSideEffectStep([PropertiesStep(property), ProfileStep, DropStep, ProfileStep])',
'annotations': {'percentDur': 8.267848997012667},
'id': '2.0.0()',
'metrics': [{'dur': 0.179074,
'counts': {'traverserCount': 1, 'elementCount': 1},
'name': 'PropertiesStep(property)',
'id': '0.1.0(2.0.0())'},
{'dur': 0.210574,
'counts': {},
'name': 'DropStep',
'id': '1.1.0(2.0.0())'}]},
{'dur': 0.092257,
'counts': {'traverserCount': 1, 'elementCount': 1},
'name': 'NoOpBarrierStep',
'annotations': {'percentDur': 1.6484381407314508},
'id': '9.0.0()'},
{'dur': 1.653211,
'counts': {'traverserCount': 1, 'elementCount': 1},
'name': 'AddPropertyStep({value=[SomeName123], key=[name123]})#[X]',
'annotations': {'percentDur': 29.539396111696483},
'id': '3.0.0()'},
{'dur': 0.116915,
'counts': {'traverserCount': 1, 'elementCount': 1},
'name': 'GraphStep(vertex,[22b515e0-dbef-b359-10f3-71ff13527bb2])',
'annotations': {'percentDur': 2.0890246292814374},
'id': '4.0.0()'},
{'dur': 1.073502,
'counts': {'traverserCount': 1, 'elementCount': 1},
'name': 'TraversalSideEffectStep([VertexStep(OUT,edge), ProfileStep, DropStep, ProfileStep])',
'annotations': {'percentDur': 19.181218129263836},
'id': '5.0.0()',
'metrics': [{'dur': 0.14199,
'counts': {'traverserCount': 11, 'elementCount': 11},
'name': 'VertexStep(OUT,edge)',
'id': '0.1.0(5.0.0())'},
{'dur': 0.879906,
'counts': {},
'name': 'DropStep',
'id': '1.1.0(5.0.0())'}]},
{'dur': 0.042369,
'counts': {'traverserCount': 1, 'elementCount': 1},
'name': 'NoOpBarrierStep',
'annotations': {'percentDur': 0.7570447292308533},
'id': '10.0.0()'},
{'dur': 1.645534,
'counts': {'traverserCount': 1, 'elementCount': 1},
'name': 'AddEdgeStep({~to=[[SelectOneStep(last,X), ProfileStep]], label=[some edge]})',
'annotations': {'percentDur': 29.40222430244195},
'id': '6.0.0()',
'metrics': [{'dur': 0.024292,
'counts': {'traverserCount': 1, 'elementCount': 1},
'name': 'SelectOneStep(last,X)',
'id': '0.1.0(6.0.0())'}]}]}
For 3:
{'dur': 9.084957,
'metrics': [{'dur': 0.340621,
'counts': {'traverserCount': 1, 'elementCount': 1},
'name': 'NeptuneGraphQueryStep(Vertex)',
'annotations': {'percentDur': 3.7492857698721083},
'id': '6.0.0()'},
{'dur': 1.92865,
'counts': {'traverserCount': 1, 'elementCount': 1},
'name': 'TraversalSideEffectStep([VertexStep(OUT,edge), ProfileStep, DropStep, ProfileStep])',
'annotations': {'percentDur': 21.229049295445208},
'id': '1.0.0()',
'metrics': [{'dur': 0.282423,
'counts': {'traverserCount': 11, 'elementCount': 11},
'name': 'VertexStep(OUT,edge)',
'id': '0.1.0(1.0.0())'},
{'dur': 1.578817,
'counts': {},
'name': 'DropStep',
'id': '1.1.0(1.0.0())'}]},
{'dur': 0.058816,
'counts': {'traverserCount': 1, 'elementCount': 1},
'name': 'NoOpBarrierStep',
'annotations': {'percentDur': 0.647399872118272},
'id': '5.0.0()'},
{'dur': 6.75687,
'counts': {'traverserCount': 1, 'elementCount': 1},
'name': 'AddEdgeStep({~to=[[GraphStep(vertex,[8b66cab2-3b1c-41c9-9acb-296dda3c9139]), ProfileStep, TraversalSideEffectStep([PropertiesStep(property), ProfileStep, DropStep, ProfileStep]), ProfileStep, NoOpBarrierStep, ProfileStep, AddPropertyStep({value=[SomeName123], key=[name123]}), ProfileStep]], label=[some edge]})',
'annotations': {'percentDur': 74.37426506256442},
'id': '2.0.0()',
'metrics': [{'dur': 0.087179,
'counts': {'traverserCount': 1, 'elementCount': 1},
'name': 'GraphStep(vertex,[8b66cab2-3b1c-41c9-9acb-296dda3c9139])',
'id': '0.1.0(2.0.0())'},
{'dur': 0.332149,
'counts': {'traverserCount': 1, 'elementCount': 1},
'name': 'TraversalSideEffectStep([PropertiesStep(property), ProfileStep, DropStep, ProfileStep])',
'id': '1.1.0(2.0.0())',
'metrics': [{'dur': 0.144028,
'counts': {'traverserCount': 1, 'elementCount': 1},
'name': 'PropertiesStep(property)',
'id': '0.2.0(1.1.0(2.0.0()))'},
{'dur': 0.159151,
'counts': {},
'name': 'DropStep',
'id': '1.2.0(1.1.0(2.0.0()))'}]},
{'dur': 0.052224,
'counts': {'traverserCount': 1, 'elementCount': 1},
'name': 'NoOpBarrierStep',
'id': '3.1.0(2.0.0())'},
{'dur': 5.781101,
'counts': {'traverserCount': 1, 'elementCount': 1},
'name': 'AddPropertyStep({value=[SomeName123], key=[name123]})',
'id': '2.1.0(2.0.0())'}]}]}
There are around 300k vertices and 3 million edges in the graph database (AWS Neptune).
Am I missing something here? I wanted to make it work with method-1 as this is a part of a complex traversal which might not work well with method-2

Answer 1

Judging from the profile() of the three queries, Neptune is not optimizing the child traversal of to(V().hasLabel('SomeLabel').has('name','SomeName')). It's doing a full graph scan for V() in that case denoted by this:
{'dur': 8820.813613,
'counts': {'traverserCount': 1, 'elementCount': 1},
'name': 'AddEdgeStep({~to=[[GraphStep(vertex,[]), ProfileStep, NeptuneHasStep([~label.eq(SomeLabel), name.eq(SomeName)]), ProfileStep, TraversalSideEffectStep([PropertiesStep(property), ProfileStep, DropStep, ProfileStep]), ProfileStep, NoOpBarrierStep, ProfileStep, AddPropertyStep({value=[SomeName123], key=
[name123]}), ProfileStep]], label=[some edge]})',
'annotations': {'percentDur': 99.97353970560806},
'id': '2.0.0()',
'metrics': [{'dur': 1346.058324,
'counts': {'traverserCount': 373732, 'elementCount': 373732},
'name': 'GraphStep(vertex,[])',
'id': '0.1.0(2.0.0())'},
{'dur': 7473.661772,
'counts': {'traverserCount': 1, 'elementCount': 1},
'name': 'NeptuneHasStep([~label.eq(SomeLabel), name.eq(SomeName)])',
'id': '5.1.0(2.0.0())'},
See the traverser count for V() is 373732 which feeds into has() which does a 7 second in-memory filter to find 1 vertex.