[jira] [Comment Edited] (TINKERPOP-2767) Repeat Out Times traversal hangs indefinitely on first execution

["Cole Greer (Jira)" <ji...@apache.org>]

    [ https://issues.apache.org/jira/browse/TINKERPOP-2767?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=17675797#comment-17675797 ] 

Cole Greer edited comment on TINKERPOP-2767 at 1/12/23 3:30 AM:
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I've tried running the example go file using gremlingo 3.6.1 against gremlin-server 3.6.1 in docker. I'm seeing the same behavior that Simon reported. If I run the script against a fresh server which just finished booting, it will hang indefinitely. After killing the driver and trying again, it returns as normal. The issue only appears during the first execution.

I was trying to narrow down what size of traversal is needed to reproduce this behavior and found something interesting.
{code:java}
g.With("evaluationTimeout", 1000).V("1").Repeat(gremlingo.T__.Out()).Times(int32( X )).Next(){code}

Will always hang on the first execution with X >= 1292. It will never hang if X <= 1291 though.

On the other hand, this traversal:
{code:java}
g.With("evaluationTimeout", 1000).V("1").Repeat(gremlingo.T__.Both()).Times(int32( X )).Next(){code}

Will always hang (even on repeated executions) with X >= 10 but will never hang with X <= 9.


was (Author: JIRAUSER296563):
I've tried running the example go file using gremlingo 3.6.1 against gremlin-server 3.6.1 in docker. I'm seeing the same behavior that Simon reported. If I run the script against a fresh server which just finished booting, it will hang indefinitely. After killing the driver and trying again, it returns as normal. The issue only appears during the first execution.

I was trying to narrow down what size of traversal is needed to reproduce this behavior and found something interesting.
g.With("evaluationTimeout", 1000).V("1").Repeat(gremlingo.T__.Out()).Times(int32( X )).Next()
Will always hang on the first execution with X >= 1292. It will never hang if X <= 1291 though.

On the other hand, this traversal:
g.With("evaluationTimeout", 1000).V("1").Repeat(gremlingo.T__.Both()).Times(int32( X )).Next()
Will always hang (even on repeated executions) with X >= 10 but will never hang with X <= 9.

> Repeat Out Times traversal hangs indefinitely on first execution
> ----------------------------------------------------------------
>
>                 Key: TINKERPOP-2767
>                 URL: https://issues.apache.org/jira/browse/TINKERPOP-2767
>             Project: TinkerPop
>          Issue Type: Bug
>          Components: javascript
>    Affects Versions: 3.5.3
>         Environment: Windows 10
>            Reporter: Simon Zhao
>            Priority: Major
>
> Originally encountered when fixing TINKERPOP-2754
>  
> The following traversal in JS seems to cause hanging the first time you run it on a newly launched gremlin-server (3.5.3) via docker
>  
> {{await g.V('1').repeat(_.out()).times(1500).next();}}
>  
> The same hanging occurs in gremlin-go. 
>  
> {code:java}
> _, err = g.With("evaluationTimeout", 1000).V("1").Repeat(gremlingo.T__.Out()).Times(int32(1500)).Next() {code}
>  
> The timeout is optional, but indicates that something is going wrong since it is not returning. Interestingly enough, if the timeout is very low, then it won't hang because it will say the timeout was exceeded. This indicates that if the traversal is completed within the timeout, it's just not returning for some reason on the first call.
>  
> If you were to write a script and invoke this snippet of code, it will hang. If you forcefully terminate the script and rerun it, then it doesn't hang.
>  
> main.go
> {code:java}
> package main
> import (
>    gremlingo "github.com/apache/tinkerpop/gremlin-go/v3/driver"
>    "log"
> )
> func main() {
>    driver, err := gremlingo.NewDriverRemoteConnection("ws://localhost:45940/gremlin")
>    if err != nil {
>       log.Print("Err creating DRC")
>       return
>    }
>    defer driver.Close()
>    log.Println("Start")
>    g := gremlingo.Traversal_().WithRemote(driver)
>    LABEL := "test"
>    _, err = g.V().HasLabel(LABEL).Drop().Next()
>    _, err = g.AddV(LABEL).Property(gremlingo.T.Id, "1").Next()
>    _, err = g.AddV(LABEL).Property(gremlingo.T.Id, "2").Next()
>    _, err = g.AddE(LABEL).From(gremlingo.T__.V("1")).To(gremlingo.T__.V("2")).Property(gremlingo.T.Id, "e1").Next()
>    _, err = g.AddE(LABEL).From(gremlingo.T__.V("2")).To(gremlingo.T__.V("1")).Property(gremlingo.T.Id, "e2").Next()
>    if err != nil {
>       log.Println("Error during setup")
>       return
>    }
>    log.Println("Start the problematic traversal")
>    _, err = g.With("evaluationTimeout", 1000).V("1").Repeat(gremlingo.T__.Out()).Times(int32(1500)).Next()
>    if err != nil {
>       log.Println("Error with the problematic traversal, but we didn't hang")
>       return
>    }
>    log.Println("End")
> } {code}



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