Server Errors when sending temporary files (JDK regression?)

[fm3]

Context

Task creation with initial data (Trying to create 250 tasks based on uploaded zips)

Expected Behavior

task annotation bases should be created with the initial data

Current Behavior

124 tasks successfully created, 119 failed
I see occurences of

backend: 2022-04-27 15:59:56,798 [error] com.scalableminds.webknossos.datastore.rpc.RPCRequest - Error sending WS request to http://localhost:9000/tracings/volume/2c174c09-6ed3-4264-aa8b-3ca043a0a30c/initialData (ID: 425): /tmp/playtemp6106843044668276672/data.zip9932978374925623459
backend: akka.stream.impl.io.FileSource$$anon$2.preStart(IOSources.scala:68)
backend:     akka.stream.impl.fusing.GraphInterpreter.init(GraphInterpreter.scala:306)
backend:     akka.stream.impl.fusing.GraphInterpreterShell.init(ActorGraphInterpreter.scala:594)
backend:     akka.stream.impl.fusing.ActorGraphInterpreter.tryInit(ActorGraphInterpreter.scala:702)
backend:     akka.stream.impl.fusing.ActorGraphInterpreter.preStart(ActorGraphInterpreter.scala:751)
backend:     akka.actor.Actor.aroundPreStart(Actor.scala:548)
backend:     akka.actor.Actor.aroundPreStart$(Actor.scala:548)
backend:     akka.stream.impl.fusing.ActorGraphInterpreter.aroundPreStart(ActorGraphInterpreter.scala:691)
backend:     akka.actor.ActorCell.create(ActorCell.scala:643)
backend:     akka.actor.ActorCell.invokeAll$1(ActorCell.scala:513)
backend:     akka.actor.ActorCell.systemInvoke(ActorCell.scala:535)
backend:     akka.dispatch.Mailbox.processAllSystemMessages(Mailbox.scala:295)
backend:     akka.dispatch.Mailbox.run(Mailbox.scala:230)
backend:     java.base/java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1130)
backend:     java.base/java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:630)
backend:     java.base/java.lang.Thread.run(Thread.java:832)

and

backend: 2022-04-27 16:00:02,435 [error] akka.actor.RepointableActorRef - Error during preStart in [akka.stream.impl.io.FileSource$$anon$2-fileSource]: /tmp/playtemp6106843044668276672/data.zip7533579796494177102
backend: java.nio.file.NoSuchFileException: /tmp/playtemp6106843044668276672/data.zip7533579796494177102
backend: 	at akka.stream.impl.io.FileSource$$anon$2.preStart(IOSources.scala:68)
backend: 	at akka.stream.impl.fusing.GraphInterpreter.init(GraphInterpreter.scala:306)
backend: 	at akka.stream.impl.fusing.GraphInterpreterShell.init(ActorGraphInterpreter.scala:594)
backend: 	at akka.stream.impl.fusing.ActorGraphInterpreter.tryInit(ActorGraphInterpreter.scala:702)
backend: 	at akka.stream.impl.fusing.ActorGraphInterpreter.preStart(ActorGraphInterpreter.scala:751)
backend: 	at akka.actor.Actor.aroundPreStart(Actor.scala:548)
backend: 	at akka.actor.Actor.aroundPreStart$(Actor.scala:548)
backend: 	at akka.stream.impl.fusing.ActorGraphInterpreter.aroundPreStart(ActorGraphInterpreter.scala:691)
backend: 	at akka.actor.ActorCell.create(ActorCell.scala:643)

Steps to Reproduce the bug

Create hybrid task type

Create tasks, based on the zip of zips linked in https://discuss.webknossos.org/t/task-creation-failed/1723/3
(Note that this requires a dataset with the name mentioned in the nml files)

As discussed in TheHive-Project/TheHive#1089 and hmrc/binding-tariff-trader-frontend#329 this sounds like a regression in openjdk. I could not test OpenJDK 15 an up. (could not install 15on my system; 16 and up as are not yet supported by Play 2.8.)

It may be worth considering not using temporary files but passing the content in-memory