Performance degradation in TinkerGraph 3.5.4 and 3.5.5

Hello,

I few days ago I tried to update gremlin-server in our project from 3.5.3 to 3.5.4 and found out that it's test suite got 5 times slower. We use the official docker image(tinkerpop/gremlin-server) with some configuration changes:

gremlin.tinkergraph.vertexIdManager=ANY
gremlin.tinkergraph.edgeIdManager=ANY 

The app uses user-generated string ids and heavily relies on the upsert pattern from the recipes.

Yesterday I made an investigation and narrowed it down to the performance of the upsert pattern. I also discovered that the issue is not related to our configuration changes and can be reproduced with vanilla image and LONG ids.

I prepared a simple script that reproduces the issue and contacted Stephen Mallette on discord. They confirmed the issue exists, but only in 3.5.4, 3.6.0 performs as expected. They also wrote a groovy script that reproduces the problem:

g = TinkerGraph.open().traversal()
batches = (0..<100).collect{ (0..<100) }
start = System.currentTimeMillis()
for (batch in batches) {
  b = g
  for (id in batch) {
    b = b.V(id).fold().coalesce(__.unfold(), __.addV("test").property(T.id, id))
  }
  b.iterate()
}
System.currentTimeMillis() - start

discord message

Both my and Stephen's scripts perform a few times slower when executed against 3.5.4 in compare to 3.5.3 or 3.6.0.

Steps to reproduce:

Run my or Stephen's script against vanilla tinkerpop/gremlin-server:3.5.4 docker image

Expected result:

Script's execution time matches it's time when executed against 3.5.3 or 3.6.0

Observed result:

The script is 5-7 times slower.