[TINKERPOP-2365] LazyBarrierStrategy adds a NoOpBarrierStep when profile() is present

• Type: Bug
• Status: Closed
• Priority: Minor
• Resolution: Fixed
• Affects Version/s: 3.3.10
• Fix Version/s: 3.5.0, 3.3.11, 3.4.7
• Component/s: process
• Assignee: Stephen Mallette
• Reporter: Stephen Mallette
• Created: 29/Apr/20 13:31
• Updated: 08/May/20 17:16
• Resolved: 08/May/20 17:16

Description

Not sure if this needs to behave like this for any particular reason but:

gremlin> g.V().both().profile()
==>Traversal Metrics
Step                                                               Count  Traversers       Time (ms)    % Dur
=============================================================================================================
TinkerGraphStep(vertex,[])                                             1           1           0.055    67.30
VertexStep(BOTH,vertex)                                                2           2           0.012    15.51
NoOpBarrierStep(2500)                                                  2           1           0.014    17.19
                                            >TOTAL                     -           -           0.082        -

the NoOpBarrierStep doesn't get added unless profile() is present as shown in this explain():

gremlin> g.V().both().explain()
==>Traversal Explanation
========================================================================================
Original Traversal                 [GraphStep(vertex,[]), VertexStep(BOTH,vertex)]

ConnectiveStrategy           [D]   [GraphStep(vertex,[]), VertexStep(BOTH,vertex)]
MatchPredicateStrategy       [O]   [GraphStep(vertex,[]), VertexStep(BOTH,vertex)]
EarlyLimitStrategy           [O]   [GraphStep(vertex,[]), VertexStep(BOTH,vertex)]
FilterRankingStrategy        [O]   [GraphStep(vertex,[]), VertexStep(BOTH,vertex)]
InlineFilterStrategy         [O]   [GraphStep(vertex,[]), VertexStep(BOTH,vertex)]
IncidentToAdjacentStrategy   [O]   [GraphStep(vertex,[]), VertexStep(BOTH,vertex)]
AdjacentToIncidentStrategy   [O]   [GraphStep(vertex,[]), VertexStep(BOTH,vertex)]
RepeatUnrollStrategy         [O]   [GraphStep(vertex,[]), VertexStep(BOTH,vertex)]
CountStrategy                [O]   [GraphStep(vertex,[]), VertexStep(BOTH,vertex)]
PathRetractionStrategy       [O]   [GraphStep(vertex,[]), VertexStep(BOTH,vertex)]
LazyBarrierStrategy          [O]   [GraphStep(vertex,[]), VertexStep(BOTH,vertex)]
TinkerGraphCountStrategy     [P]   [GraphStep(vertex,[]), VertexStep(BOTH,vertex)]
TinkerGraphStepStrategy      [P]   [TinkerGraphStep(vertex,[]), VertexStep(BOTH,vertex)]
ProfileStrategy              [F]   [TinkerGraphStep(vertex,[]), VertexStep(BOTH,vertex)]
StandardVerificationStrategy [V]   [TinkerGraphStep(vertex,[]), VertexStep(BOTH,vertex)]

Final Traversal                    [TinkerGraphStep(vertex,[]), VertexStep(BOTH,vertex)]

unless of course we explain() the profile() which seems weird:

gremlin> g.V().both().profile().explain()
==>Traversal Explanation
==========================================================================================================================================================================================================
Original Traversal                 [GraphStep(vertex,[]), VertexStep(BOTH,vertex), ProfileSideEffectStep, SideEffectCapStep([~metrics])]

ConnectiveStrategy           [D]   [GraphStep(vertex,[]), VertexStep(BOTH,vertex), ProfileSideEffectStep, SideEffectCapStep([~metrics])]
MatchPredicateStrategy       [O]   [GraphStep(vertex,[]), VertexStep(BOTH,vertex), ProfileSideEffectStep, SideEffectCapStep([~metrics])]
EarlyLimitStrategy           [O]   [GraphStep(vertex,[]), VertexStep(BOTH,vertex), ProfileSideEffectStep, SideEffectCapStep([~metrics])]
FilterRankingStrategy        [O]   [GraphStep(vertex,[]), VertexStep(BOTH,vertex), ProfileSideEffectStep, SideEffectCapStep([~metrics])]
InlineFilterStrategy         [O]   [GraphStep(vertex,[]), VertexStep(BOTH,vertex), ProfileSideEffectStep, SideEffectCapStep([~metrics])]
IncidentToAdjacentStrategy   [O]   [GraphStep(vertex,[]), VertexStep(BOTH,vertex), ProfileSideEffectStep, SideEffectCapStep([~metrics])]
AdjacentToIncidentStrategy   [O]   [GraphStep(vertex,[]), VertexStep(BOTH,vertex), ProfileSideEffectStep, SideEffectCapStep([~metrics])]
RepeatUnrollStrategy         [O]   [GraphStep(vertex,[]), VertexStep(BOTH,vertex), ProfileSideEffectStep, SideEffectCapStep([~metrics])]
CountStrategy                [O]   [GraphStep(vertex,[]), VertexStep(BOTH,vertex), ProfileSideEffectStep, SideEffectCapStep([~metrics])]
PathRetractionStrategy       [O]   [GraphStep(vertex,[]), VertexStep(BOTH,vertex), ProfileSideEffectStep, SideEffectCapStep([~metrics])]
LazyBarrierStrategy          [O]   [GraphStep(vertex,[]), VertexStep(BOTH,vertex), NoOpBarrierStep(2500), ProfileSideEffectStep, SideEffectCapStep([~metrics])]
TinkerGraphCountStrategy     [P]   [GraphStep(vertex,[]), VertexStep(BOTH,vertex), NoOpBarrierStep(2500), ProfileSideEffectStep, SideEffectCapStep([~metrics])]
TinkerGraphStepStrategy      [P]   [TinkerGraphStep(vertex,[]), VertexStep(BOTH,vertex), NoOpBarrierStep(2500), ProfileSideEffectStep, SideEffectCapStep([~metrics])]
ProfileStrategy              [F]   [TinkerGraphStep(vertex,[]), ProfileStep, VertexStep(BOTH,vertex), ProfileStep, NoOpBarrierStep(2500), ProfileStep, ProfileSideEffectStep, SideEffectCapStep([~metrics]
                                      )]
StandardVerificationStrategy [V]   [TinkerGraphStep(vertex,[]), ProfileStep, VertexStep(BOTH,vertex), ProfileStep, NoOpBarrierStep(2500), ProfileStep, ProfileSideEffectStep, SideEffectCapStep([~metrics]
                                      )]

Final Traversal                    [TinkerGraphStep(vertex,[]), ProfileStep, VertexStep(BOTH,vertex), ProfileStep, NoOpBarrierStep(2500), ProfileStep, ProfileSideEffectStep, SideEffectCapStep([~metrics]
                                      )]

Seems like this is a bit of a bug in the sense that I would expect explain() and profile() to examine the same working traversal up to the point of that call.