Hi, we use Akka.net for a while in our production environment already. recently, we are looking at Akka.net streams, and I have a question about it.
Let's say I have an Order class.
class Order {
public string OrderID {get;set;}
...
}
the logic is, we collect a bunch of orders and transform, save to database, a typically ETL process.
the prototype could be like this:
List<Order> orders = new List<Order>();
orders.add(new Order("orderID1"));
orders.add(new Order("orderID2"));
Source.From(orders).select(x=>x.OrderID = x.OrderID + "123").RunForeach(Console.WriteLine());
After that, obviously, the original order collection, each order's ID has _123 appended, so my question is, through each flow, should I create a new instance of Order and transform on the new instance, then pass the new one to the next flow, in other words, keep the original collection element immutable.
Hi! I have a problem with clustering. I have 2 nodes which use sharding, and some lighthouses. After I restarted the nodes, they joined the cluster without issues, but the sharded actors cannot be spawned. The errors I get look like this:
Trying to register to coordinator at ["/system/sharding/ps_filesCoordinator/singleton/coordinator"], but no acknowledgement. Total [1600] buffered messages.
And there is a ton of them spamming all the time. The root cause seems to be related to restoring state of shard coordinator
{
"Depth": 0,
"ClassName": "System.ArgumentException",
"Message": "Region [akka://Oddjob/system/sharding/ps_files#1292415200] not registered\r\nParameter name: e",
"Source": "Akka.Cluster.Sharding",
"StackTraceString": " at Akka.Cluster.Sharding.PersistentShardCoordinator.State.Updated(IDomainEvent e)\r\n at Akka.Cluster.Sharding.PersistentShardCoordinator.ReceiveRecover(Object message)\r\n at Akka.Persistence.Eventsourced.<RecoveryStarted>b__90_0(Object message)\r\n at Akka.Actor.ActorBase.AroundReceive(Receive receive, Object message)\r\n at Akka.Persistence.Eventsourced.<>c__DisplayClass92_0.<Recovering>b__0(Receive receive, Object message)",
"RemoteStackTraceString": null,
"RemoteStackIndex": 0,
"ExceptionMethod": {
"Name": "Updated",
"AssemblyName": "Akka.Cluster.Sharding",
"AssemblyVersion": "1.3.2.0",
"AssemblyCulture": "",
"ClassName": "Akka.Cluster.Sharding.PersistentShardCoordinator+State",
"Signature": "State Updated(IDomainEvent)",
"MemberType": 8
},
"HResult": -2147024809,
"HelpURL": null
}
Exception in ReceiveRecover when replaying event type ["Akka.Cluster.Sharding.PersistentShardCoordinator+ShardHomeAllocated"] with sequence number [8] for persistenceId ["/system/sharding/ps_filesCoordinator/singleton/coordinator"]The wierd thing is that it fails on sequence number 8 when there is 21 entries in the DB.
Any pointers on what could be the cause of the error here? I don't understand what "Region not registered" means :|
(I know that I can probably fix it by purging the DB, but I'd like to understand why is it happening).
@Horusiath Do you think this might help ?
http://getakka.net/articles/clustering/cluster-sharding.html#retrieving-sharding-state
http://getakka.net/articles/clustering/cluster-sharding.html#retrieving-sharding-state
Hi, I'm trying to set the result of Context.GetLogger() at runtime to something different. Is this possible, and how would I do this? I don't want to use the Hocon to do this, because I want the logging infrastructure to do something unique for each ActorSystem that's running.
Hi guys, I'm doing a demo project using akka cluster and facing a problem to send message to the cluster actor. Already run Lighthouse project as Seed-Nodes and I also can deploy the actor remotely and having actor reference but the actor are not able to receiving a message. If i change user-role=api then it can receive a message
class Program
{
static void Main(string[] args)
{
var config = ConfigurationFactory.ParseString(@"
akka {
actor {
provider = ""Akka.Cluster.ClusterActorRefProvider, Akka.Cluster""
}
remote {
log-remote-lifecycle-events = DEBUG
dot-netty.tcp {
hostname = ""127.0.0.1""
port = 5001
}
}
cluster {
#will inject this node as a self-seed node at run-time
seed-nodes = [""akka.tcp://akkademo@127.0.0.1:4053""]
roles = [actorserver]
}
}
");
using (ActorSystem system = ActorSystem.Create("akkademo",config))
{
Console.ReadLine();
}
}
}and here is the API cluster side
class Program
{
static void Main(string[] args)
{
var config = ConfigurationFactory.ParseString(@"
akka {
actor {
provider = ""Akka.Cluster.ClusterActorRefProvider, Akka.Cluster""
deployment {
/actorServerGraphQL {
router = round-robin-pool
nr-of-instances = 10
cluster {
enabled = on
max-nr-of-instances-per-node = 2
allow-local-routees = on
use-role = actorserver
}
}
}
}
remote {
log-remote-lifecycle-events = DEBUG
dot-netty.tcp {
hostname = ""127.0.0.1""
port = 5002
}
}
cluster {
#will inject this node as a self-seed node at run-time
seed-nodes = [""akka.tcp://akkademo@127.0.0.1:4053""]
roles = [api]
}
}
");
using (ActorSystem system = ActorSystem.Create("akkademo", config))
{
var actorServer = system.ActorOf(Props.Create<ActorServerGraphQL>().WithRouter(FromConfig.Instance), "actorServerGraphQL");
actorServer.Tell(new QueryDatabase("Start query"));
//var apiActor = system.ActorOf(Props.Create(() => new ApiActor(actorServer)), "apiActor");
//apiActor.Tell(new QueryDatabase("Start query"));
Console.ReadLine();
}
}
}
Do you think this might help ? http://getakka.net/articles/clustering/cluster-sharding.html#retrieving-sharding-state
@jalchr sorry, but I'm out of the context.
I've wrote once a blog post where I've described all query messages, that can be used to communicate with cluster sharding: https://petabridge.com/blog/cluster-sharding-technical-overview-akkadotnet/#getting-shard-metadata
On GetShardRegionState shard region will reply with ShardRegionState containing data about shards living in the current actor system and what entities are alive on each one of them.
On GetClusterShardingStats shard region will reply with ClusterShardingStats having information about shards living in the whole cluster and how many entities alive in each one of them.
very well ...
@wilddeveloperappears you still can set up a separate HOCON config for each ActorSystem, with different logging in mind. In general it's not possible to setup a separate logging adapter per actor, as logging is running within actor system event stream. It doesn't discriminate different actors.
@jalchr yes, for a single shard, you have corresponding message types described bellow in the same article
with
Tell, shard will simply respond to a message sender (an actor)
it looks like you're trying to contact with sharded actor instead of shard itself
How to talk with the "shard" itself ?
@jachlr in your case
_shard is actually ShardRegion. General notion is that:- Actors managed by cluster sharding often are referred to as entities
- Entities are grouped in shards. Entities within the same shard always live on the same machine, when they are rebalanced to another one, they are always rebalanced together. If you want to get reference to target shard, keep in mind that shard is an actor parent for it's entities (so you can use
Context.Parentfrom within entity). - Shards themselves are grouped within shard regions. Shard region is a container for all shards of a given actor type living on a target actor system.
Very well, my ApiMaster is trying to launch a new "File Processing" operation .. I'm trying to detect if a 'job' is already running or not
private void HandleFindRunningJob(FindRunningNewVideo newVideo)
{
//var state = _shard.Ask<Shard.CurrentShardState>(Shard.GetCurrentShardState.Instance).Result;
//var exists = state.EntityIds.Contains(newVideo.File.ToLower());
var haveChild = Context.Child(newVideo.File.ToLower());
if (haveChild != ActorRefs.Nobody)
{
ApiBroadcaster.Tell(new NewVideoFound(newVideo.File));
_mediator.Tell(new Publish(Topics.Reporting, new ReportStatus(ReportStatusEnum.Info,
$"HandleFindRunningJob() : 'already processed' file = {newVideo.File}"
)));
_logger.Info($"HandleFindRunningJob() : 'already processed' file = {newVideo.File}");
}
}
usually "job" describes some stateless behavior - cluster sharding has more sense in stateful problems (when you have a logical domain entity like User, Department, Vehicle etc.). You don't need to check if entity is alive, as you shouldn't care about that. If it's running, just queue the next message for it, it will be picked up at some point. If it's not alive it will be created ad-hoc and start processing the message.
I see what you mean. I have FileProcessing to be a stateful problem. It undergoes several steps. I need to make sure I have 1 actor (entity) per file.
Cause now, the duplicate jobs are causing file locking issues (a file is being used by another process) sort of things.
Before I move to persistent actors, I used var haveChild = Context.Child(newVideo.File.ToLower()); ...
Now, I'm using shards and entities ... I need to mimic the same functionality ...
Much Appreciated
@jalchr you can just post message to an entity - it will be created ad-hoc if it wasn't alive. Just keep in mind, that sharded entities are a bit slower and more heavyweight than normal actors (because of all automatic lifecycle and cluster message routing machanisms).
I'm experience "shortage" in communication ....
here is a sample log file
here is a sample log file
2017-12-09 16:03:35,998 [6] WARN Akka.Cluster.ClusterCoreDaemon - Cluster Node [akka.tcp://ArchiveSystem@140.125.4.1:16568] - Marking node(s) as UNREACHABLE [Member(address = akka.tcp://ArchiveSystem@140.125.4.2:16668, Uid=81451205 status = Up, role=[importer-old], upNumber=21), Member(address = akka.tcp://ArchiveSystem@140.125.4.3:16666, Uid=807193699 status = Up, role=[web], upNumber=19)]. Node roles [importer,pubsub-node]
2017-12-09 16:03:36,013 [6] INFO Akka.Cluster.ClusterCoreDaemon - Marking node(s) as REACHABLE [Member(address = akka.tcp://ArchiveSystem@140.125.4.2:16668, Uid=81451205 status = Up, role=[importer-old], upNumber=21)]. Node roles [importer,pubsub-node]
2017-12-09 16:03:36,013 [6] INFO Archive.Shared.Cluster.ClusterStatus - UnreachableMember: Member(address = akka.tcp://ArchiveSystem@140.125.4.2:16668, Uid=81451205 status = Up, role=[importer-old], upNumber=21), Role(s): importer-old
2017-12-09 16:03:36,013 [6] INFO Archive.Shared.Cluster.ClusterStatus - UnreachableMember: Member(address = akka.tcp://ArchiveSystem@140.125.4.3:16666, Uid=807193699 status = Up, role=[web], upNumber=19), Role(s): web
2017-12-09 16:03:36,013 [6] INFO Akka.Cluster.ClusterCoreDaemon - Leader can currently not perform its duties, reachability status: [Reachability([akka.tcp://ArchiveSystem@140.125.4.1:16568 -> UniqueAddress: (akka.tcp://ArchiveSystem@140.125.4.2:16668, 81451205): Reachable [Reachable] (29)], [akka.tcp://ArchiveSystem@140.125.4.1:16568 -> UniqueAddress: (akka.tcp://ArchiveSystem@140.125.4.3:16666, 807193699): Unreachable [Unreachable] (28)])], member status: [$akka.tcp://ArchiveSystem@140.125.4.1:16568 $Up seen=$True, $akka.tcp://ArchiveSystem@140.125.4.1:16668 $Up seen=$False, $akka.tcp://ArchiveSystem@140.125.4.2:16568 $Up seen=$False, $akka.tcp://ArchiveSystem@140.125.4.2:16668 $Up seen=$False, $akka.tcp://ArchiveSystem@140.125.4.3:16666 $Up seen=$False, $akka.tcp://ArchiveSystem@140.125.4.4:16666 $Up seen=$False, $akka.tcp://ArchiveSystem@140.125.4.5:4053 $Up seen=$False, $akka.tcp://ArchiveSystem@140.125.4.6:4053 $Up seen=$False]
2017-12-09 16:03:36,138 [6] INFO Archive.Shared.Cluster.ClusterStatus - ReachableMember: Member(address = akka.tcp://ArchiveSystem@140.125.4.2:16668, Uid=81451205 status = Up, role=[importer-old], upNumber=21), Role(s): importer-old
2017-12-09 16:03:36,138 [6] WARN Archive.Shared.Cluster.ClusterStatus - Unreachable Member; Role: web, Status: Up, Address:
2017-12-09 16:03:36,138 [6] WARN Archive.Shared.Cluster.ClusterStatus - Unreachable Member; Role: web, Status: Up, Address: akka.tcp://ArchiveSystem@140.125.4.3:16666,
2017-12-09 16:03:36,138 [6] WARN Archive.Shared.Cluster.ClusterStatus - Unreachable Member; Role: web, Status: Up, Address: akka.tcp://ArchiveSystem@140.125.4.3:16666,
2017-12-09 16:03:36,154 [6] WARN Archive.Shared.Cluster.ClusterStatus - Unreachable Member; Role: web, Status: Up, Address: akka.tcp://ArchiveSystem@140.125.4.3:16666,
2017-12-09 16:03:36,154 [6] WARN Archive.Shared.Cluster.ClusterStatus - Unreachable Member; Role: web, Status: Up, Address: akka.tcp://ArchiveSystem@140.125.4.3:16666,
2017-12-09 16:03:36,154 [6] WARN Archive.Shared.Cluster.ClusterStatus - Unreachable Member; Role: web, Status: Up, Address: akka.tcp://ArchiveSystem@140.125.4.3:16666,
2017-12-09 16:03:36,154 [6] WARN Archive.Shared.Cluster.ClusterStatus - Unreachable Member; Role: web, Status: Up, Address: akka.tcp://ArchiveSystem@140.125.4.3:16666,
2017-12-09 16:03:36,154 [6] WARN Archive.Shared.Cluster.ClusterStatus - Unreachable Member; Role: web, Status: Up, Address: akka.tcp://ArchiveSystem@140.125.4.3:16666,
2017-12-09 16:03:36,154 [6] WARN Archive.Shared.Cluster.ClusterStatus - Unreachable Member; Role: web, Status: Up, Address: akka.tcp://ArchiveSystem@140.125.4.3:16666,
2017-12-09 16:03:36,170 [6] WARN Archive.Shared.Cluster.ClusterStatus - Unreachable Member; Role: web, Status: Up, Address:
I have more than 2 roles ... "web" which is the front-end web application and "importer" which is the video processing service.
I noticed that after few days of running ... the combination of lighthouse and other roles ... somehow cause this
I noticed that after few days of running ... the combination of lighthouse and other roles ... somehow cause this
I'm hosting this on 6 VMs (2 web , 2 processing ... 2 lighthouse)
and for the record, the IIS recycles the web app after some idle time ... so it is natural to become 'unreachable'
I wish I can reproduce this
unreachable is normal part when machine crashes or network connection goes down - if its possible its better to gracefully signal if node is going offline.
This is what I do in IIS ... asp.net app
//==============================================================
HandleStarted();
var properties = new AppProperties(app.Properties);
var token = properties.OnAppDisposing;
if (token != CancellationToken.None)
{
token.Register(() =>
{
// do stuff here for ending / disposing
HandleStopped();
log.Info("ASP.NET application stopped !");
});
}
log.Info("ASP.NET application started !");private void HandleStopped()
{
log.Info("ASP.NET application stopped");
if (ClusterSystem == null) return;
log.Debug("Leaving cluster");
ClusterHelper.Tell(new ClusterHelper.RemoveMember());
var cluster = Akka.Cluster.Cluster.Get(ClusterSystem);
cluster.RegisterOnMemberRemoved(() => MemberRemoved(ClusterSystem));
cluster.Leave(cluster.SelfAddress);
asTerminatedEvent.WaitOne(20000);
ClusterSystem.Terminate().Wait(20000);
log.Info("Actor system terminated, exiting");
}
private async void MemberRemoved(ActorSystem actorSystem)
{
log.Info("Member removed ...");
await actorSystem.Terminate();
this.asTerminatedEvent.Set();
}
Internal messages fail:
2017-12-09 16:03:43,795 [56] INFO Akka.Actor.LocalActorRef - Message Shutdown from akka://ArchiveSystem/system/sharding/FileHandler/67/%5C%5Cnas20%5Cd%24%5Carchive%5Cincoming%5Creuters%5C201712096110wd-northkorea-missilescontributors.xml/$c to akka://ArchiveSystem/system/sharding/FileHandler/67/%5C%5Cnas20%5Cd%24%5Carchive%5Cincoming%5Creuters%5C201712096110wd-northkorea-missilescontributors.xml/$c was not delivered. 4 dead letters encountered.
2017-12-09 16:03:43,826 [56] INFO Akka.Actor.LocalActorRef - Message FileValidationResult from akka://ArchiveSystem/system/sharding/FileHandler/67/%5C%5Cnas20%5Cd%24%5Carchive%5Cincoming%5Creuters%5C201712096110wd-northkorea-missilescontributors.xml/$c to akka://ArchiveSystem/system/sharding/FileHandler/67/%5C%5Cnas20%5Cd%24%5Carchive%5Cincoming%5Creuters%5C201712096110wd-northkorea-missilescontributors.xml was not delivered. 5 dead letters encountered.