[akka-user] ActorSystem terminates when restarted remote ActorSystem has associated after being quarantined
Hi, I have two ActorSystems Node-A and Node-B in separate JVM processes with netty-tcp remoting enabled running on the same machine (127.0.0.1) on port 2552 and 2553. Each ActorSystem starts itself a actor. The actor sends a ping message and replies to a sender with a pong message using actorSelection which identifies the corresponding remote actor. On receiving a ping or pong message the sender actor is going to be watched. Everything works fine so far. Then I kill the JVM process which was running ActorSystem Node-B. Node-A detects the termination and after a while the remote system Node-B becomes quarantined. Now I restart the JVM process to launch the ActorSystem Node-B. The ActorSystem Node-A notifies that Node-B is associated. In the same instant ActorSystem Node-A terminates without any log message or exception. Node-B continues and notifies about that termination This unexpected behaviour is reproducible. Are there any known issues when quarantined ActorSystems are restarted? Akka Version used: 2.3.9 Tested with: JRE 7 and 8 OS: Windows 7 x64 Stacktrace of thread which stops the ActorSystem due to receival of message DeathWatchNotification(Actor[akka://Node-A/user],true,false): Node-A-akka.actor.default-dispatcher-14@2655 prio=5 tid=0x19 nid=NA runnable java.lang.Thread.State: RUNNABLE at akka.actor.LocalActorRefProvider$$anon$2.stop(ActorRefProvider.scala:491) at akka.actor.LocalActorRefProvider$$anon$2$$anonfun$sendSystemMessage$1.apply$mcV$sp(ActorRefProvider.scala:506) at akka.util.Switch.ifOff(LockUtil.scala:85) at akka.actor.LocalActorRefProvider$$anon$2.sendSystemMessage(ActorRefProvider.scala:499) at akka.actor.dungeon.FaultHandling$class.akka$actor$dungeon$FaultHandling$$finishTerminate(FaultHandling.scala:213) at akka.actor.dungeon.FaultHandling$class.handleChildTerminated(FaultHandling.scala:292) at akka.actor.ActorCell.handleChildTerminated(ActorCell.scala:369) at akka.actor.dungeon.DeathWatch$class.watchedActorTerminated(DeathWatch.scala:63) at akka.actor.ActorCell.watchedActorTerminated(ActorCell.scala:369) at akka.actor.ActorCell.invokeAll$1(ActorCell.scala:455) at akka.actor.ActorCell.systemInvoke(ActorCell.scala:478) at akka.dispatch.Mailbox.processAllSystemMessages(Mailbox.scala:279) at akka.dispatch.Mailbox.run(Mailbox.scala:220) at akka.dispatch.Mailbox.exec(Mailbox.scala:231) at scala.concurrent.forkjoin.ForkJoinTask.doExec(ForkJoinTask.java:260) at scala.concurrent.forkjoin.ForkJoinPool$WorkQueue.runTask(ForkJoinPool.java:1339) at scala.concurrent.forkjoin.ForkJoinPool.runWorker(ForkJoinPool.java:1979) at scala.concurrent.forkjoin.ForkJoinWorkerThread.run(ForkJoinWorkerThread.java:107) -- Read the docs: http://akka.io/docs/ Check the FAQ: http://doc.akka.io/docs/akka/current/additional/faq.html Search the archives: https://groups.google.com/group/akka-user --- You received this message because you are subscribed to the Google Groups Akka User List group. To unsubscribe from this group and stop receiving emails from it, send an email to akka-user+unsubscr...@googlegroups.com. To post to this group, send email to akka-user@googlegroups.com. Visit this group at http://groups.google.com/group/akka-user. For more options, visit https://groups.google.com/d/optout.
Re: [akka-user] [akka-persistence-2.3.9] Saving snapshots of multiple objects
On Wed, Mar 25, 2015 at 11:55 AM, Patrik Nordwall patrik.nordw...@gmail.com wrote: Hi Amir, On Sun, Mar 22, 2015 at 8:57 PM, Amir Karimi a.karim...@gmail.com wrote: Hi, I have an actor with multiple states. What is the best practice to save snapshots of them: - Aggregating all states into one case class and just have a single big state object - This is hard when we have to update deeper states. Like state.copy(innerState = state.innerState.copy(...)) And for updating deep case class hierarchies you can use lens pattern from scalaz or monocle or something simpler like quicklens http://www.warski.org/blog/2015/02/quicklens-modify-deeply-nested-case-class-fields/ . This is the way to do it. I see no other way. Note that the state object that you pass to saveSnapshot doesn't have to be the same as the state object you have in your actor. You can have several state variables in the actor and then combine them into one object when you perform saveSnapshot. - Call saveSnapshot for each state object - I'm not sure what happens if one of the snapshot savings fail This will not work. When the actor is recovering it will only receive one snapshot followed by the events after that snapshot. /Patrik What is the best solution? Thanks, Amir -- Read the docs: http://akka.io/docs/ Check the FAQ: http://doc.akka.io/docs/akka/current/additional/faq.html Search the archives: https://groups.google.com/group/akka-user --- You received this message because you are subscribed to the Google Groups Akka User List group. To unsubscribe from this group and stop receiving emails from it, send an email to akka-user+unsubscr...@googlegroups.com. To post to this group, send email to akka-user@googlegroups.com. Visit this group at http://groups.google.com/group/akka-user. For more options, visit https://groups.google.com/d/optout. -- Patrik Nordwall Typesafe http://typesafe.com/ - Reactive apps on the JVM Twitter: @patriknw -- Read the docs: http://akka.io/docs/ Check the FAQ: http://doc.akka.io/docs/akka/current/additional/faq.html Search the archives: https://groups.google.com/group/akka-user --- You received this message because you are subscribed to the Google Groups Akka User List group. To unsubscribe from this group and stop receiving emails from it, send an email to akka-user+unsubscr...@googlegroups.com. To post to this group, send email to akka-user@googlegroups.com. Visit this group at http://groups.google.com/group/akka-user. For more options, visit https://groups.google.com/d/optout. -- Martynas Mickevičius Typesafe http://typesafe.com/ – Reactive http://www.reactivemanifesto.org/ Apps on the JVM -- Read the docs: http://akka.io/docs/ Check the FAQ: http://doc.akka.io/docs/akka/current/additional/faq.html Search the archives: https://groups.google.com/group/akka-user --- You received this message because you are subscribed to the Google Groups Akka User List group. To unsubscribe from this group and stop receiving emails from it, send an email to akka-user+unsubscr...@googlegroups.com. To post to this group, send email to akka-user@googlegroups.com. Visit this group at http://groups.google.com/group/akka-user. For more options, visit https://groups.google.com/d/optout.
[akka-user] How does akka actor helps in achieve concurrency without locking/syncronization
How does using akka actor helps in achieving concurrency without use of any external locks? Is it because at a moment only one message can be processed for one actor ? Hence no 2 threads can be acting upon same actor ? If that is the case, then maximum number of threads we require is equal to number of actors in our system. -- Read the docs: http://akka.io/docs/ Check the FAQ: http://doc.akka.io/docs/akka/current/additional/faq.html Search the archives: https://groups.google.com/group/akka-user --- You received this message because you are subscribed to the Google Groups Akka User List group. To unsubscribe from this group and stop receiving emails from it, send an email to akka-user+unsubscr...@googlegroups.com. To post to this group, send email to akka-user@googlegroups.com. Visit this group at http://groups.google.com/group/akka-user. For more options, visit https://groups.google.com/d/optout.
Re: [akka-user] Re: Akka CQRS / Cluster Sharding - Change management of Events and other questions
Thanks for the help guys! I figured I stumbled onto a big topic here. :) @Richard - I haven't used Scala Pickling, though I do have some experience with scodec for binary serialization. One problem I have with binary serialization with akka-persistence is it makes it makes it harder to debug systems just from querying the database. This seems to be an issue with some plugins in the ecosystem - thankfully the one I'm using just provided support for a pluggable way of handling serialization for the persistence API. Avro looks interesting - I'll have to follow that one a bit longer. I also recently discovered https://github.com/mandubian/scaledn but haven't used it yet. I think I'm going to go the json-serialization route as my team already has a lot of experience using the play-json formatters/reads/writes so it would flow quite naturally. I also really like the idea of storing events in the DB in a human readable format. As per 2), I'm still a bit confused on the scenario if the system crashes after the command is persisted but before the event callback is fired (or right in the middle of the callback). This seems like it would be a relatively common scenario, and the suggested event-sourcing approaches recommend not to perform side effects while recovering state. -Chris On Monday, April 13, 2015 at 2:35:05 PM UTC-4, Greg Young wrote: Yep weak/hybrid schema all the way. So long as adding a field doesn't break downstream consumers then you are #@$@ed with schema (think binary serializer) On Mon, Apr 13, 2015 at 9:29 PM, Richard Rodseth rrod...@gmail.com javascript: wrote: My favourite topic https://groups.google.com/forum/#!topic/akka-user/mNVxRPRUDv0 Jay Kreps recently strongly endorsed Avro for use with Kafka. http://t.co/l9uTFmb6OS On Mon, Apr 13, 2015 at 10:54 AM, Greg Young gregor...@gmail.com javascript: wrote: For 1 use weak serialization (say json) On Monday, April 13, 2015 at 4:54:24 PM UTC+3, Chris Ridmann wrote: Hello! I've recently been experimenting with architectures that use CQRS / Cluster Sharding / Event Sourcing / DDD, and I have some beginner questions. 1) What is the best way to handle changing the structure of events as business requirements (or refactorings) change over time? As a brief example: // v1 case class ChangeName(id: String, first:String) extends Cmd case class NameChanged(id: String, first: String) extends Evt // v2 // now biz req. changes and we want to be able to change both first and last name // i can freely change the 'Cmd' because we don't persist it, however if I change the 'Evt' // i will get 'RecoveryFailure was caused by: java.io.InvalidClassException' during recoveries case class ChangeName(id: String, first:String, last: String) extends Cmd case class NameChanged(id: String, first: String, last: String) extends Evt It seems I could always just maintain 2 different events, e.g. NameChangedV1, and NameChangedV2, but that doesn't seem maintainable in the long run. Another approach I thought of is to save a snapshot before introducing any breaking changes to an Event interface before bringing down the app for upgrading. This seems hard - is it even possible with the 'ClusterSharding' extension to send a message (e.g. Snap) to all of its known id's in the system? How does changing events affect the read side of things in CQRS? 2) When a node crashes, how can I make sure the entry gets restarted and completes processing when the node is brought back up? Here's a very brief example that may help clarify what I'm asking: // sent in the beginning of the flow from a front-end case class ProcessMessage(id: String, message: Message) extends Cmd case class MessageToBeProcessed(id: String, message: Message) extends Evt // sent at the end of the flow from another processor actor case class MessageProcessed(id: String, message: Message) extends Cmd case class MessageComplete(id: String, message: Message) extends Evt Let's say the node crashes right after I persist the event 'MessageToBeProcessed' and before I send it to a processor actor to complete processing. Will the 'ClusterSharding' extension re-activate this entry on another available node right away, or will it wait until that entry receives another Cmd? If it doesn't re-activate, is there a recommended approach to solve this? Thanks! -Chris -- Read the docs: http://akka.io/docs/ Check the FAQ: http://doc.akka.io/docs/akka/current/additional/faq.html Search the archives: https://groups.google.com/group/akka-user --- You received this message because you are subscribed to the Google Groups Akka User List group. To unsubscribe from this group and stop receiving
[akka-user] Re: Akka Tuning - need help - not getting as advertised performance
Are you using ReactiveMongo? If so what version? Have you investigated
bulkInsert, perhaps buffer locally and only flushing when a certain limit
is reached?
What do your write queues in MMS look like?
Can you clarify what actors you believe are not terminating properly?
On Friday, April 10, 2015 at 1:07:01 PM UTC-4, Dan Martin wrote:
I have a feeling that what's happing is my actors are not terminating
gracefully. See, my benchmark app runs for a finite time. Once that time
is reach, it shuts down the actor system. I believe there are messages in
the actor mailboxes that don't get processed. I'm just now reading through
some documentation about graceful shutdowns.
http://letitcrash.com/post/30165507578/shutdown-patterns-in-akka-2
On Friday, April 10, 2015 at 12:25:15 PM UTC-4, Dan Martin wrote:
I'm building an app-monitoring application in Play 2 and MongoDB 3.
Basic usage is client application log messeges via REST endpoints provide
by my Play app. For benchmark testing, I put together a client tool where
I use Akka to simulate application requests. I'm using the Akka Scheduler
to send messages to a logBotActor (LogBot is the name of my benchmark
tool). The logBotActor pics from a random set of messages that I have
predefined in a list and sends them to sendMessageActor for sending the
HTTP request to my app monitory application
The scheduler is configured to run at a 1ms interval. So, in theory, I
should see 1000 messages logged on the backend (MongoDb) for each second
that goes by, but Im not. In fact, I'm no where near that figure. I
understand that there's latency involved (my app-monitor is running on
Heroku). I also understand that from the time the scheduler kicks off a
message, CPU clock cycles go by as messages are passed around between the
actors and performing the random calculation for getting random predefined
messages. But eventually, it should all catch up, right??
I'm just getting my feet wet with Akka, so I'm sure there's some tuning
that needs to be addressed.
Here is my application.conf. (note: I omitted the debugging related
properties). I've tried adjusting the parallelism-max and throughput but
they didn't seem to effect anything.
akka {
actor {
default-dispatcher {
executor = fork-join-executor
fork-join-executor {
parallelism-factor = 2.0
parallelism-max = 10
parallelism-min = 2
}
throughput = 100
}
}
}
Here are my machine's specs:
*MacBook Pro (15-inch, 2.53GHz, Mid 2009)*
*Processor* 2.53 GHz Intel Core 2 Duo
*Memory* 8 GB 1067 MHz DDR3
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Re: [akka-user] How does akka actor helps in achieve concurrency without locking/syncronization
On 04/15/15 04:47, Rohit Jain wrote: How does using akka actor helps in achieving concurrency without use of any external locks? Is it because at a moment only one message can be processed for one actor ? Hence no 2 threads can be acting upon same actor ? that is correct. processing within the receive loop of an actor is single threaded. If that is the case, then maximum number of threads we require is equal to number of actors in our system. if all your actors perform blocking work in their receive loop, then that would be true. however, you should design your application to be non-blocking (http://www.reactivemanifesto.org/glossary#Non-Blocking). if you need to perform blocking work, then you should use Futures (http://doc.akka.io/docs/akka/2.3.9/scala/futures.html) to schedule the work on a separate, dedicated dispatcher (http://doc.akka.io/docs/akka/2.3.9/scala/dispatchers.html). You can then pipe the result of the Future to an actor (http://doc.akka.io/docs/akka/2.3.9/scala/futures.html#Use_With_Actors) for further processing if necessary. -Michael -- Read the docs: http://akka.io/docs/ Check the FAQ: http://doc.akka.io/docs/akka/current/additional/faq.html Search the archives: https://groups.google.com/group/akka-user --- You received this message because you are subscribed to the Google Groups Akka User List group. To unsubscribe from this group and stop receiving emails from it, send an email to akka-user+unsubscr...@googlegroups.com. To post to this group, send email to akka-user@googlegroups.com. Visit this group at http://groups.google.com/group/akka-user. For more options, visit https://groups.google.com/d/optout.
Re: [akka-user] Simple HOCON question
On 04/15/15 09:53, bearrito wrote: Cross posted to stackoverflow http://stackoverflow.com/questions/29655888/hocon-not-substituting-environment-variables Anyone have any experience with this issue. Is what I'm attempting even feasible? this is a shot in the dark, but are you using an older version of typesafe-config? maybe its a newer-ish feature? the feature seems to be advertised as you describe, but if you are pulling in typesafe-config as a transient dependency (say from akka), maybe you are getting an older version. what happens if you remove the substitution in your .conf file (so parsing is successful) and then print out the contents of ConfigFactory.systemEnvironment()? for reference: http://typesafehub.github.io/config/latest/api/com/typesafe/config/ConfigFactory.html#systemEnvironment-- -Michael -- Read the docs: http://akka.io/docs/ Check the FAQ: http://doc.akka.io/docs/akka/current/additional/faq.html Search the archives: https://groups.google.com/group/akka-user --- You received this message because you are subscribed to the Google Groups Akka User List group. To unsubscribe from this group and stop receiving emails from it, send an email to akka-user+unsubscr...@googlegroups.com. To post to this group, send email to akka-user@googlegroups.com. Visit this group at http://groups.google.com/group/akka-user. For more options, visit https://groups.google.com/d/optout.
[akka-user] Simple HOCON question
Cross posted to stackoverflow http://stackoverflow.com/questions/29655888/hocon-not-substituting-environment-variables Anyone have any experience with this issue. Is what I'm attempting even feasible? Thanks in advance, -barrett -- Read the docs: http://akka.io/docs/ Check the FAQ: http://doc.akka.io/docs/akka/current/additional/faq.html Search the archives: https://groups.google.com/group/akka-user --- You received this message because you are subscribed to the Google Groups Akka User List group. To unsubscribe from this group and stop receiving emails from it, send an email to akka-user+unsubscr...@googlegroups.com. To post to this group, send email to akka-user@googlegroups.com. Visit this group at http://groups.google.com/group/akka-user. For more options, visit https://groups.google.com/d/optout.
Re: [akka-user] How does akka actor helps in achieve concurrency without locking/syncronization
Correct me If I am wrong, because of message communication design it inherently provides distributed locking as well. On Wednesday, April 15, 2015 at 10:37:36 PM UTC+5:30, Michael Frank wrote: On 04/15/15 04:47, Rohit Jain wrote: How does using akka actor helps in achieving concurrency without use of any external locks? Is it because at a moment only one message can be processed for one actor ? Hence no 2 threads can be acting upon same actor ? that is correct. processing within the receive loop of an actor is single threaded. If that is the case, then maximum number of threads we require is equal to number of actors in our system. if all your actors perform blocking work in their receive loop, then that would be true. however, you should design your application to be non-blocking (http://www.reactivemanifesto.org/glossary#Non-Blocking). if you need to perform blocking work, then you should use Futures ( http://doc.akka.io/docs/akka/2.3.9/scala/futures.html) to schedule the work on a separate, dedicated dispatcher ( http://doc.akka.io/docs/akka/2.3.9/scala/dispatchers.html). You can then pipe the result of the Future to an actor ( http://doc.akka.io/docs/akka/2.3.9/scala/futures.html#Use_With_Actors) for further processing if necessary. -Michael -- Read the docs: http://akka.io/docs/ Check the FAQ: http://doc.akka.io/docs/akka/current/additional/faq.html Search the archives: https://groups.google.com/group/akka-user --- You received this message because you are subscribed to the Google Groups Akka User List group. To unsubscribe from this group and stop receiving emails from it, send an email to akka-user+unsubscr...@googlegroups.com. To post to this group, send email to akka-user@googlegroups.com. Visit this group at http://groups.google.com/group/akka-user. For more options, visit https://groups.google.com/d/optout.
[akka-user] What is diffrence between actor, actor instance and actorref
What is actually an Actor in context of code. Is it the java class which extends UnTypedActor ? i.e. 1 Actor=1 Class. If yes, do we have multiple instance of it, simple referred using actorref. How does multiple instance of actorref for same actor differs from each other ? What do we mean by actor failing or restart of an actor ? Do we just reload the class with last persisted data variables ? -- Read the docs: http://akka.io/docs/ Check the FAQ: http://doc.akka.io/docs/akka/current/additional/faq.html Search the archives: https://groups.google.com/group/akka-user --- You received this message because you are subscribed to the Google Groups Akka User List group. To unsubscribe from this group and stop receiving emails from it, send an email to akka-user+unsubscr...@googlegroups.com. To post to this group, send email to akka-user@googlegroups.com. Visit this group at http://groups.google.com/group/akka-user. For more options, visit https://groups.google.com/d/optout.
[akka-user] Re: 500 ISE for Client Side Error Bug Report
I was originally thinking that this would be inconvenient for ES clients. I could work around that. However for anyone attempting to build a transparent proxy in front of ES (where they can't control client calls), this would be an impossible to fix solution if a GET with body was forbidden. -- Read the docs: http://akka.io/docs/ Check the FAQ: http://doc.akka.io/docs/akka/current/additional/faq.html Search the archives: https://groups.google.com/group/akka-user --- You received this message because you are subscribed to the Google Groups Akka User List group. To unsubscribe from this group and stop receiving emails from it, send an email to akka-user+unsubscr...@googlegroups.com. To post to this group, send email to akka-user@googlegroups.com. Visit this group at http://groups.google.com/group/akka-user. For more options, visit https://groups.google.com/d/optout.
[akka-user] Re: 500 ISE for Client Side Error Bug Report
Hmm... Spray currently allows this and products like ElasticSearch promote GET bodies. This will be a breaking change for me as well once I migrate to akka-http. How opinionated are the developers here? Can this be more of a guideline than a rule? :) -- Read the docs: http://akka.io/docs/ Check the FAQ: http://doc.akka.io/docs/akka/current/additional/faq.html Search the archives: https://groups.google.com/group/akka-user --- You received this message because you are subscribed to the Google Groups Akka User List group. To unsubscribe from this group and stop receiving emails from it, send an email to akka-user+unsubscr...@googlegroups.com. To post to this group, send email to akka-user@googlegroups.com. Visit this group at http://groups.google.com/group/akka-user. For more options, visit https://groups.google.com/d/optout.
Re: [akka-user] Simple HOCON question
My project was using an ancient version. I upgraded to 1.2.1 and it seems to be working. Go get those stackoverflow points if that is your thing! Thanks, barrett On Wednesday, April 15, 2015 at 1:19:19 PM UTC-4, Michael Frank wrote: On 04/15/15 09:53, bearrito wrote: Cross posted to stackoverflow http://stackoverflow.com/questions/29655888/hocon-not-substituting-environment-variables Anyone have any experience with this issue. Is what I'm attempting even feasible? this is a shot in the dark, but are you using an older version of typesafe-config? maybe its a newer-ish feature? the feature seems to be advertised as you describe, but if you are pulling in typesafe-config as a transient dependency (say from akka), maybe you are getting an older version. what happens if you remove the substitution in your .conf file (so parsing is successful) and then print out the contents of ConfigFactory.systemEnvironment()? for reference: http://typesafehub.github.io/config/latest/api/com/typesafe/config/ConfigFactory.html#systemEnvironment -- -Michael -- Read the docs: http://akka.io/docs/ Check the FAQ: http://doc.akka.io/docs/akka/current/additional/faq.html Search the archives: https://groups.google.com/group/akka-user --- You received this message because you are subscribed to the Google Groups Akka User List group. To unsubscribe from this group and stop receiving emails from it, send an email to akka-user+unsubscr...@googlegroups.com. To post to this group, send email to akka-user@googlegroups.com. Visit this group at http://groups.google.com/group/akka-user. For more options, visit https://groups.google.com/d/optout.
Re: [akka-user] Simple HOCON question
reposted to SO. glad i was able to help :) -Michael On 04/15/15 12:07, bearrito wrote: this is a shot in the dark, but are you using an older version of typesafe-config? maybe its a newer-ish feature? the feature seems to be advertised as you describe, but if you are pulling in typesafe-config as a transient dependency (say from akka), maybe you are getting an older version. what happens if you remove the substitution in your .conf file (so parsing is successful) and then print out the contents of ConfigFactory.systemEnvironment()? for reference: http://typesafehub.github.io/config/latest/api/com/typesafe/config/ConfigFactory.html#systemEnvironment http://typesafehub.github.io/config/latest/api/com/typesafe/config/ConfigFactory.html#systemEnvironment-- -- Read the docs: http://akka.io/docs/ Check the FAQ: http://doc.akka.io/docs/akka/current/additional/faq.html Search the archives: https://groups.google.com/group/akka-user --- You received this message because you are subscribed to the Google Groups Akka User List group. To unsubscribe from this group and stop receiving emails from it, send an email to akka-user+unsubscr...@googlegroups.com. To post to this group, send email to akka-user@googlegroups.com. Visit this group at http://groups.google.com/group/akka-user. For more options, visit https://groups.google.com/d/optout.
[akka-user] Re: Number of actors
Thanks for you reply. I will look into the aggregator pattern. On Wednesday, April 15, 2015 at 1:45:33 AM UTC-4, Adam wrote: Hi, First of all, actors are very lightweight and you can have many of them, while an ActorSystem is heavyweight and you should not have many of that (typically you'd have one). As for the pattern you describe - it all depends on the fine details, but if I had to implement a service that needs to get a set of details and was permitted (and required) to return partial results depending on some timeout, I'd have one actor to manage the request, sending the smaller sub requests and I'd indeed use the scheduler to cut this off if tge timeout expires. It might be useful for you to take a look at the aggregator pattern referenced from the docs. It has a lot in common with this. -- Read the docs: http://akka.io/docs/ Check the FAQ: http://doc.akka.io/docs/akka/current/additional/faq.html Search the archives: https://groups.google.com/group/akka-user --- You received this message because you are subscribed to the Google Groups Akka User List group. To unsubscribe from this group and stop receiving emails from it, send an email to akka-user+unsubscr...@googlegroups.com. To post to this group, send email to akka-user@googlegroups.com. Visit this group at http://groups.google.com/group/akka-user. For more options, visit https://groups.google.com/d/optout.
[akka-user] Re: Number of actors
Hi Anil, I provide the Aggregator pattern and approximately 60 others in my upcoming book Reactive Enterprise with Actor Model. It's written for Scala and Akka, and you can see the preview here: https://www.safaribooksonline.com/library/view/reactive-enterprise-with/9780133846904/ Best, Vaughn On Wednesday, April 15, 2015 at 7:33:10 PM UTC-6, Anil M wrote: Thanks for you reply. I will look into the aggregator pattern. On Wednesday, April 15, 2015 at 1:45:33 AM UTC-4, Adam wrote: Hi, First of all, actors are very lightweight and you can have many of them, while an ActorSystem is heavyweight and you should not have many of that (typically you'd have one). As for the pattern you describe - it all depends on the fine details, but if I had to implement a service that needs to get a set of details and was permitted (and required) to return partial results depending on some timeout, I'd have one actor to manage the request, sending the smaller sub requests and I'd indeed use the scheduler to cut this off if tge timeout expires. It might be useful for you to take a look at the aggregator pattern referenced from the docs. It has a lot in common with this. -- Read the docs: http://akka.io/docs/ Check the FAQ: http://doc.akka.io/docs/akka/current/additional/faq.html Search the archives: https://groups.google.com/group/akka-user --- You received this message because you are subscribed to the Google Groups Akka User List group. To unsubscribe from this group and stop receiving emails from it, send an email to akka-user+unsubscr...@googlegroups.com. To post to this group, send email to akka-user@googlegroups.com. Visit this group at http://groups.google.com/group/akka-user. For more options, visit https://groups.google.com/d/optout.
Re: [akka-user] How does akka actor helps in achieve concurrency without locking/syncronization
On Wednesday, April 15, 2015 at 10:37:36 PM UTC+5:30, Michael Frank wrote: On 04/15/15 04:47, Rohit Jain wrote: How does using akka actor helps in achieving concurrency without use of any external locks? Is it because at a moment only one message can be processed for one actor ? Hence no 2 threads can be acting upon same actor ? that is correct. processing within the receive loop of an actor is single threaded. How does akka make sure that while processing a certain message, no other message thread will be processed or there will be no context switch ? Or it just uses low level constructs of locking on a certain message before processing it, even though context switch for that message thread happens, it wont release the lock till message is processed (This can cause trouble in blocking I/O). If that is the case, then maximum number of threads we require is equal to number of actors in our system. if all your actors perform blocking work in their receive loop, then that would be true. however, you should design your application to be non-blocking (http://www.reactivemanifesto.org/glossary#Non-Blocking). if you need to perform blocking work, then you should use Futures ( http://doc.akka.io/docs/akka/2.3.9/scala/futures.html) to schedule the work on a separate, dedicated dispatcher ( http://doc.akka.io/docs/akka/2.3.9/scala/dispatchers.html). You can then pipe the result of the Future to an actor ( http://doc.akka.io/docs/akka/2.3.9/scala/futures.html#Use_With_Actors) for further processing if necessary. -Michael -- Read the docs: http://akka.io/docs/ Check the FAQ: http://doc.akka.io/docs/akka/current/additional/faq.html Search the archives: https://groups.google.com/group/akka-user --- You received this message because you are subscribed to the Google Groups Akka User List group. To unsubscribe from this group and stop receiving emails from it, send an email to akka-user+unsubscr...@googlegroups.com. To post to this group, send email to akka-user@googlegroups.com. Visit this group at http://groups.google.com/group/akka-user. For more options, visit https://groups.google.com/d/optout.
[akka-user] PubSub and lost (?) messages
Hello!
I have 2 actors. deployed to different nodes on cluster:
On consumer:
val mediator = DistributedPubSubExtension(context.system).mediator
override def preStart(): Unit = {
log.debug(Subscribing to urls ⇒ {}, self)
mediator ! Subscribe(urls, self)
}
and on producer:
val mediator = DistributedPubSubExtension(context.system).mediator
...
mediator ! Publish(urls, GiveMeWork)
I have the test, that verifies the flow between those actors - it starts
the cluster locally and sets up the environment. It works 100% correctly
locally, but when running on TeamCity - 1 times of 5 it gets stuck. In logs
I can see that the message was sent to urls topic, but it seems never
delivered to the consumer. With debug logs enabled and tracing the dead
letters I see nothing suspicious - there are no dead letters.
Is it possible that the message may get lost, or consumer unsubscribes
from the topic somehow? I double checked the logs, and the message is sent
to the topic after the consumers are subscribed to it - but it would be
nice to be able to trace down the delivery of the message in the topic.
Thanks!
Akka 2.3.9, Scala 2.11
P/S I'd like to create some simple test case out of my code, but it's
rather complicated and involves FSM actors, so I'd like to try other
advices before diving into this ice-hole.
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[akka-user] Re: 500 ISE for Client Side Error Bug Report
Hi Kevin, see https://github.com/akka/akka/blob/release-2.3-dev/akka-http-core/src/main/scala/akka/http/model/HttpMessage.scala#L133 Cheers, André On Wednesday, April 15, 2015 at 4:51:33 AM UTC+2, Kevin Meredith wrote: There's a Github issue, titled, 500 ISE for Client Side Error - https://github.com/akka/akka/issues/17187. For the below error, I grepped for cc2 [ERROR] [04/13/2015 16:01:07.698] [cloud-controller-akka.actor.default-dispatcher-27] [ActorSystem(cloud-controller)] Internal server error, sending 500 response cc2 java.lang.IllegalArgumentException: requirement failed: Requests with this method must have an empty entity cc2 at scala.Predef$.require(Predef.scala:219) $ cd akka $ grep -r method must have an empty entity * | grep -vi test | grep -vi spec $ Where does this code exist? Thanks -- Read the docs: http://akka.io/docs/ Check the FAQ: http://doc.akka.io/docs/akka/current/additional/faq.html Search the archives: https://groups.google.com/group/akka-user --- You received this message because you are subscribed to the Google Groups Akka User List group. To unsubscribe from this group and stop receiving emails from it, send an email to akka-user+unsubscr...@googlegroups.com. To post to this group, send email to akka-user@googlegroups.com. Visit this group at http://groups.google.com/group/akka-user. For more options, visit https://groups.google.com/d/optout.
Re: [akka-user] [akka-ClusterSharding 2.3.7/2.3.9] After ClusterShardFailover ShardAllocation gets lost
Hi again! Out of interest, how is it possible to receive a terminated messages from Nodes which are still running? First I suspected that maybe the leave-command causes a terminated message if a watch an actor on a different Node, but my tests showed that this is not the case, so why is this the case for ShardRegions? I didn't find anything suspicious in the code of the ShardRegion? So maybe you can enlighten me I'm really curious ;) Regards Wolfgang Am Mittwoch, 15. April 2015 08:01:21 UTC+2 schrieb Wolfgang Friedl: Hi Patrik! I've created an issue for this. Thanks for the fast reply. Wolfgang -- Read the docs: http://akka.io/docs/ Check the FAQ: http://doc.akka.io/docs/akka/current/additional/faq.html Search the archives: https://groups.google.com/group/akka-user --- You received this message because you are subscribed to the Google Groups Akka User List group. To unsubscribe from this group and stop receiving emails from it, send an email to akka-user+unsubscr...@googlegroups.com. To post to this group, send email to akka-user@googlegroups.com. Visit this group at http://groups.google.com/group/akka-user. For more options, visit https://groups.google.com/d/optout.
Re: [akka-user] [akka-ClusterSharding 2.3.7/2.3.9] After ClusterShardFailover ShardAllocation gets lost
On Wed, Apr 15, 2015 at 8:16 AM, Wolfgang Friedl wolfgang.fri...@hotmail.com wrote: Hi again! Out of interest, how is it possible to receive a terminated messages from Nodes which are still running? It watched an actor that was running on a node (ActorSystem) that was part of the cluster, and when that node is removed from the cluster death watch will trigger. The lifecycle of the actor itself and the ActorSystem for that matter is not tied to the cluster membership, by default. That is the bug in this case. Actors started by cluster sharding must be stopped when the node is removed from the cluster. First I suspected that maybe the leave-command causes a terminated message if a watch an actor on a different Node, but my tests showed that this is not the case, so why is this the case for ShardRegions? I didn't find anything suspicious in the code of the ShardRegion? So maybe you can enlighten me I'm really curious ;) The missing code is that when it receives MemberRemoved with its own address it should context.stop(self). /Patrik Regards Wolfgang Am Mittwoch, 15. April 2015 08:01:21 UTC+2 schrieb Wolfgang Friedl: Hi Patrik! I've created an issue for this. Thanks for the fast reply. Wolfgang -- Read the docs: http://akka.io/docs/ Check the FAQ: http://doc.akka.io/docs/akka/current/additional/faq.html Search the archives: https://groups.google.com/group/akka-user --- You received this message because you are subscribed to the Google Groups Akka User List group. To unsubscribe from this group and stop receiving emails from it, send an email to akka-user+unsubscr...@googlegroups.com. To post to this group, send email to akka-user@googlegroups.com. Visit this group at http://groups.google.com/group/akka-user. For more options, visit https://groups.google.com/d/optout. -- Patrik Nordwall Typesafe http://typesafe.com/ - Reactive apps on the JVM Twitter: @patriknw -- Read the docs: http://akka.io/docs/ Check the FAQ: http://doc.akka.io/docs/akka/current/additional/faq.html Search the archives: https://groups.google.com/group/akka-user --- You received this message because you are subscribed to the Google Groups Akka User List group. To unsubscribe from this group and stop receiving emails from it, send an email to akka-user+unsubscr...@googlegroups.com. To post to this group, send email to akka-user@googlegroups.com. Visit this group at http://groups.google.com/group/akka-user. For more options, visit https://groups.google.com/d/optout.
Re: [akka-user] [akka-ClusterSharding 2.3.7/2.3.9] After ClusterShardFailover ShardAllocation gets lost
On Wed, Apr 15, 2015 at 10:36 AM, Wolfgang Friedl wolfgang.fri...@hotmail.com wrote: Got it! I saw I made a mistake in my sample. When I'm watching an actor on a Node which is leaving the cluster I now got an Terminated message! Thanks for the clarification. You're welcome. Thanks for reporting! -- Read the docs: http://akka.io/docs/ Check the FAQ: http://doc.akka.io/docs/akka/current/additional/faq.html Search the archives: https://groups.google.com/group/akka-user --- You received this message because you are subscribed to the Google Groups Akka User List group. To unsubscribe from this group and stop receiving emails from it, send an email to akka-user+unsubscr...@googlegroups.com. To post to this group, send email to akka-user@googlegroups.com. Visit this group at http://groups.google.com/group/akka-user. For more options, visit https://groups.google.com/d/optout. -- Patrik Nordwall Typesafe http://typesafe.com/ - Reactive apps on the JVM Twitter: @patriknw -- Read the docs: http://akka.io/docs/ Check the FAQ: http://doc.akka.io/docs/akka/current/additional/faq.html Search the archives: https://groups.google.com/group/akka-user --- You received this message because you are subscribed to the Google Groups Akka User List group. To unsubscribe from this group and stop receiving emails from it, send an email to akka-user+unsubscr...@googlegroups.com. To post to this group, send email to akka-user@googlegroups.com. Visit this group at http://groups.google.com/group/akka-user. For more options, visit https://groups.google.com/d/optout.
[akka-user] [akka-http] parameter directive: read to a custom class
For type safety, I use a value class for IDs, like:
case class ClaimId(id: String) extends AnyVal {
override def toString: String = id
}
I'd like to read this id from a query parameter.
For the moment, I use this:
parameter('claim_id.as[String] ?) { claimId ⇒
... claimId.map(ClaimId.apply) ...
}
(see the code here:
https://github.com/sphereio/cloudqueues-simulator/blob/master/src/main/scala/io/sphere/cloudqueues/Routes.scala#L123
)
I'd prefer to read directly into a ClaimId, like that:
parameter('claim_id.as[ClaimId] ?) { claimId ⇒ ... }
Can somebody show me how to do that?
All ParamMagnet, ParamDef are sealed traits that I cannot use.
I checked the existing tests (
https://github.com/akka/akka/blob/releasing-akka-stream-and-http-experimental-1.0-M5/akka-http-tests%2Fsrc%2Ftest%2Fscala%2Fakka%2Fhttp%2Fserver%2Fdirectives%2FParameterDirectivesSpec.scala)
but have not found something similar.
Thanks,
Yann
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Re: [akka-user] [akka-ClusterSharding 2.3.7/2.3.9] After ClusterShardFailover ShardAllocation gets lost
Got it! I saw I made a mistake in my sample. When I'm watching an actor on a Node which is leaving the cluster I now got an Terminated message! Thanks for the clarification. -- Read the docs: http://akka.io/docs/ Check the FAQ: http://doc.akka.io/docs/akka/current/additional/faq.html Search the archives: https://groups.google.com/group/akka-user --- You received this message because you are subscribed to the Google Groups Akka User List group. To unsubscribe from this group and stop receiving emails from it, send an email to akka-user+unsubscr...@googlegroups.com. To post to this group, send email to akka-user@googlegroups.com. Visit this group at http://groups.google.com/group/akka-user. For more options, visit https://groups.google.com/d/optout.
