NullPointerException on receiving message for SingletonFeed actor

Hi all,

I’m getting this strange error when starting simulation, any clues for troubleshooting?

17:46:08.941 [ERROR] i.g.c.a.SingletonFeed - Actor io.gatling.core.action.SingletonFeed@2bc4aac4 crashed on message Some(FeedMessage(Session(GiveUpTrade,6,1548693968857,Map(gatling.http.ssl.sslContexts → SslContexts(io.netty.handler.ssl.OpenSslClientContext@7e910c44,None), gatling.http.cache.dns → io.gatling.http.cache.DnsCacheSupport$$anon$1@5372d7b9, gatling.http.cache.baseUrl → https://localhost:8090),0,OK,List(),io.gatling.core.protocol.ProtocolComponentsRegistry$$Lambda$453/90250170@522b0c00),io.gatling.core.session.package$ExpressionSuccessWrapper$$$Lambda$188/451312813@298f6d8c,Actor[akka://GatlingSystem/user/gatling-controller#1951901581],io.gatling.http.action.HttpRequestAction@5f8aa7d5))
java.lang.NullPointerException: null
at scala.collection.immutable.MapLike.$plus$plus(MapLike.scala:91)
at scala.collection.immutable.MapLike.$plus$plus$(MapLike.scala:90)
at scala.collection.immutable.AbstractMap.$plus$plus(Map.scala:242)
at io.gatling.core.session.Session.setAll(Session.scala:93)
at io.gatling.core.action.SingletonFeed$$anonfun$receive$1.$anonfun$applyOrElse$4(SingletonFeed.scala:48)
at io.gatling.commons.validation.Success.map(Validation.scala:42)
at io.gatling.core.action.SingletonFeed$$anonfun$receive$1.feedRecords$1(SingletonFeed.scala:48)
at io.gatling.core.action.SingletonFeed$$anonfun$receive$1.$anonfun$applyOrElse$11(SingletonFeed.scala:59)
at io.gatling.core.action.SingletonFeed$$anonfun$receive$1.$anonfun$applyOrElse$11$adapted(SingletonFeed.scala:59)
at io.gatling.commons.validation.Success.flatMap(Validation.scala:43)
at io.gatling.commons.validation.Validation.flatMap$mcI$sp(Validation.scala:30)
at io.gatling.commons.validation.Validation.flatMap$mcI$sp$(Validation.scala:30)
at io.gatling.commons.validation.Success.flatMap$mcI$sp(Validation.scala:41)
at io.gatling.core.action.SingletonFeed$$anonfun$receive$1.applyOrElse(SingletonFeed.scala:59)
at akka.actor.Actor.aroundReceive(Actor.scala:517)
at akka.actor.Actor.aroundReceive$(Actor.scala:515)
at io.gatling.core.akka.BaseActor.aroundReceive(BaseActor.scala:24)
at akka.actor.ActorCell.receiveMessage(ActorCell.scala:588)
at akka.actor.ActorCell.invoke(ActorCell.scala:557)
at akka.dispatch.Mailbox.processMailbox(Mailbox.scala:258)
at akka.dispatch.Mailbox.run(Mailbox.scala:225)
at akka.dispatch.Mailbox.exec(Mailbox.scala:235)
at akka.dispatch.forkjoin.ForkJoinTask.doExec(ForkJoinTask.java:260)
at akka.dispatch.forkjoin.ForkJoinPool$WorkQueue.runTask(ForkJoinPool.java:1339)
at akka.dispatch.forkjoin.ForkJoinPool.runWorker(ForkJoinPool.java:1979)
at akka.dispatch.forkjoin.ForkJoinWorkerThread.run(ForkJoinWorkerThread.java:107)

17:46:08.941 [ERROR] a.a.OneForOneStrategy - null
java.lang.NullPointerException: null
at scala.collection.immutable.MapLike.$plus$plus(MapLike.scala:91)
at scala.collection.immutable.MapLike.$plus$plus$(MapLike.scala:90)
at scala.collection.immutable.AbstractMap.$plus$plus(Map.scala:242)
at io.gatling.core.session.Session.setAll(Session.scala:93)
at io.gatling.core.action.SingletonFeed$$anonfun$receive$1.$anonfun$applyOrElse$4(SingletonFeed.scala:48)
at io.gatling.commons.validation.Success.map(Validation.scala:42)
at io.gatling.core.action.SingletonFeed$$anonfun$receive$1.feedRecords$1(SingletonFeed.scala:48)
at io.gatling.core.action.SingletonFeed$$anonfun$receive$1.$anonfun$applyOrElse$11(SingletonFeed.scala:59)
at io.gatling.core.action.SingletonFeed$$anonfun$receive$1.$anonfun$applyOrElse$11$adapted(SingletonFeed.scala:59)
at io.gatling.commons.validation.Success.flatMap(Validation.scala:43)
at io.gatling.commons.validation.Validation.flatMap$mcI$sp(Validation.scala:30)
at io.gatling.commons.validation.Validation.flatMap$mcI$sp$(Validation.scala:30)
at io.gatling.commons.validation.Success.flatMap$mcI$sp(Validation.scala:41)
at io.gatling.core.action.SingletonFeed$$anonfun$receive$1.applyOrElse(SingletonFeed.scala:59)
at akka.actor.Actor.aroundReceive(Actor.scala:517)
at akka.actor.Actor.aroundReceive$(Actor.scala:515)
at io.gatling.core.akka.BaseActor.aroundReceive(BaseActor.scala:24)
at akka.actor.ActorCell.receiveMessage(ActorCell.scala:588)
at akka.actor.ActorCell.invoke(ActorCell.scala:557)
at akka.dispatch.Mailbox.processMailbox(Mailbox.scala:258)
at akka.dispatch.Mailbox.run(Mailbox.scala:225)
at akka.dispatch.Mailbox.exec(Mailbox.scala:235)
at akka.dispatch.forkjoin.ForkJoinTask.doExec(ForkJoinTask.java:260)
at akka.dispatch.forkjoin.ForkJoinPool$WorkQueue.runTask(ForkJoinPool.java:1339)
at akka.dispatch.forkjoin.ForkJoinPool.runWorker(ForkJoinPool.java:1979)
at akka.dispatch.forkjoin.ForkJoinWorkerThread.run(ForkJoinWorkerThread.java:107)

Thank you,
Miroslav

Can you please share some more details like script or event.

It seems, you might have declared same feeder file name trice or more. Check Gatling & Scala objects are singleton.