DistributedData replicator actor is being created under "/user"

[Arkatufus]

Version Information
Version of Akka.NET? dev branch
Which Akka.NET Modules? Akka.DistributedData

Describe the bug
DistributedData.Replicator actor is created under "/user", should be created under "/system" instead.

Code link

akka.net/src/contrib/cluster/Akka.DistributedData/DistributedData.cs

Lines 88 to 90 in 4e30b9d

	Replicator = _settings.RestartReplicatorOnFailure
	? system.ActorOf(GetSupervisedReplicator(_settings, name), name+"Supervisor")
	: system.ActorOf(Akka.DistributedData.Replicator.Props(_settings), name);

[Aaronontheweb]

yeah if we can fix this without it breaking live Akka.Cluster systems, that'd be a good candidate for v1.5 - buuuuuuuuuuut if it's going to cause them to all "miss" each other then we should move this to v1.6, which will likely require a full cluster restart any way.

[Arkatufus]

Yeah, this is a potentially cluster breaking behavior

[Aaronontheweb]

If it is, has to go into v1.6. And no opt-out flags or whatever either - we just fix the problem and sell it as part of a full upgrade.

[Arkatufus]

Replicator expects that all other replicator actors to have the same exact actor path as it is, changing the guardian actor would not work in a mixed implementation cluster environment because the replicator running under "/user" would not be able to talk to replicator running under "/system".

akka.net/src/contrib/cluster/Akka.DistributedData/Replicator.cs

Line 1141 in 4e30b9d

private ActorSelection Replica(Address address) => Context.ActorSelection(Self.Path.ToStringWithAddress(address));

[Aaronontheweb]

Ok, we'll move this to v1.6 then