The most up to date info can be found in Typevel discord, Alex is active there: https://discord.gg/hWd4eS244g
He answered a question about the CE3 roadmap recently:
Good question. I'm trying to come up with one and it is ... complicated, because it needs to have an identity that's different from Cats-Effect & fs2.
<br><br>
The value of Monix is in its pragmatism, its approach to FP that allows for impure interfaces to live alongside the pure ones (with established conventions), its deep integration with the host, its coherence, its fairly stable backwards compatibility.
<br><br>
Unfortunately, the task at hand on deciding what to do next, isn't easy to solve, and personally I've been away, on what people call an OSS hiatus. Trying to get back on that ride though.
<br><br>
In other news, in private I'm experimenting with a new Task. I have ideas and I'm foreseeing a philosophical divergence from cats.effect.IO. If CE evolves towards Task, the question would have been if Monix's implementation makes any sense, but CE 3 has actually moved further from Task's philosophy, and now I'm thinking Task can continue to provide value, while integrating CE3 ideas and also implement its type-classes.
<br><br>
Anyway, I was thinking of getting together with Monix contributors, discuss current issues, decide on a road-map, and call for help maybe, as there's plenty to work on.
<br><br>
This does mean that we are nowhere near a new major release. Sorry for not being able to give you a better answer.
And I need to make sure that everything I fetch is 100% processed and never dropped, even when the application is shutdown.
What's the best way to make this work?
Right now I am thinking of making it
uncancelable and then in the doOnCancel of the Task somehow stopping further fetches, sending a Stop signal upstream, but upstream from the processing part, as that needs to happen. Observable
.interval(1.seconds)
.flatMap(a => Observable.fromTask(Task.delay(println(a)).as(a))) // Fetching something from API, once fetched we need to ensure it is processed
.mapEval(a => Task.sleep(2.seconds).as(a))
.uncancelable
.consumeWith(Consumer.foreachParallelTask[Long](1)(a => Task.delay(println(s"arrived at the end $a")))) // This step always HAS to be invoked
.as(ExitCode.Success)
.doOnCancel(Task.sleep(10.seconds) *> Task.delay(println("CIAO")))
Hi, someone could tell me, please.
Why this code isn't working properly?
I want to request on different links, when the Observable triggers an event.
val eventComparative = PublishSubject[String]()
val eventComparativePublish = eventComparative.publish
val cancelEventComparativePublish = eventComparativePublish.connect()
val getMinimosRetensionISR = eventComparativePublish.dump("0").mapEval { case idComparative => ...
val getProcess = eventComparativePublish.dump("0").mapEval { case idComparative => ...
val getComparativo = eventComparativePublish.dump("0").mapEval { case idComparative => ...val observableZip3 = Observable.zip3(getMinimosRetensionISR, getProcess, getComparativo)
val cmdPrint = button("Imprimir", cls := "myButton",
SyncIO ( onClick.transformLifted { event: Observable[MouseEvent] =>
event
.withLatestFrom(getIdComparative) {
case (event@_, idComparative: String) =>
idComparative
}} --> repoCompara.eventComparative
)
)PublishSubject live: Repository
val publisher = PublishSubject[String]().publish
val cancelEventComparativePublish = publisher.connect()
val o1 = eventComparativePublish.dump("Event received!")
val publishTask = Observable.repeatEvalF(Task(eventComparative.onNext("Hi")))
Observable.zip2(o1, publishTask).completedL.runSyncUnsafe()
Hi ,
I have a below use case .
Execute DB operations in async, after that is done send out a kafka event to another microservice so that it reads from DB. However as of now the kafka event is being sent even before the DB operation is complete. My code looks as below :
firstTask = Task(doSomeDBOperation).executeOn(io).asyncBoundary
secondTask = Task(doSomeDBOperation).executeOn(io).asyncBoundary
thirdTask = Task(doSomeDBUpdate).executeOn(io).asyncBoundary
Task.sequence(Seq(firstTask, secondTask, thirdTask, pushToKafkaTask))Is there any way to ensure pushToKafkaTask surely happens after the first three task ?
applicative methods, for sequential computations you use Monad methods (flatMap)
or
Task.parSequence(List(firstTask, secondTask, thirdTask)).doOnFinish(_ => pushToKafkaTask)if you want try/finally semantics
firstTask and secondTask look like :val firstTask = dbOperation1(k)
def dbOperation1(k: objPUT)(jt: JdbcTemplate, io: Scheduler): Task[Int] = {
val params = Array(user.userId, DateUtils.currentTimestamp, k.getId)
Task(jt.update(tDao.tUpdate, params: _*)).executeOn(io).asyncBoundary
}
val secondTask = dbOperation2(t.getId, t, existing)
def dbOperation2(id: String,input: objPUTGen, existing: objPUTGen = null,iStd: Boolean = true,
isNSRefUpdate: Boolean = false,)(implicit user: UserDetails, jt: JdbcTemplate): Task[_] =
Task.sequence(Seq(dbOperation3(id, input),
if (iStd) dbOperation4( id, input) else Task.unit, dbOperation5(id, input, existing, isNSRefUpdate) ))
def dbOperation3(id: String, input: TemplateGeneric)(implicit user: UserDetails, jt: JdbcTemplate, io: Scheduler): Task[_] = {
val sDel =
s"""
| delete from "tableName"
| where ID = ?
""".stripMargin
Task(jt.update(sDel, id)).executeOn(io).asyncBoundary
}
onErrorFallbackTo(Task.unit) just before any startAndForget. It's do not work so I'm wondering if the it's not reported what ever it's catch or not in UnfoldObservable.unsafeSubscribeFn.Do someone have an advice that could help me to properly control logs with (supposly) async exception?
1 reply
How do you guys manage java memory when running in container environment (eg k8s) while using monix io sheduler (Scheduler.io())
IO scheduler is unbounded so it may spawn undefined number of threads. Threads keep stacks out of java heap space (xmx) so we cannot limit them.
Therefore in case of huge number of IO operations using Scheduler.io may lead to OOM errors on the container.
Do you deal with that / manage that somehow?
assign api and not the usual subscribe api on the KafkaConsumer object. Is this supported ? Could I get some pointers please ?
1 reply
hi there, I am trying to assemble a fat jar with monix using sbt assembly and I am getting these errors:
[error] deduplicate: different file contents found in the following:
[error] /Users/anirudh.vyas/Library/Caches/Coursier/v1/https/repo1.maven.org/maven2/io/monix/monix-internal-jctools_3/3.4.0/monix-internal-jctools_3-3.4.0.jar:scala/runtime/function/JProcedure18.class
[error] /Users/anirudh.vyas/Library/Caches/Coursier/v1/https/repo1.maven.org/maven2/org/scala-lang/scala3-library_3/3.1.2/scala3-library_3-3.1.2.jar:scala/runtime/function/JProcedure18.class
[error] deduplicate: different file contents found in the following:any suggestions for me?
libraryDependencies += "io.monix" %% "monix" % "3.4.0",lazy val assemblySettings = Seq(
assembly / assemblyMergeStrategy := {
case PathList("module-info.class") => MergeStrategy.discard
case path if path.contains("META-INF/services") => MergeStrategy.concat
case PathList("META-INF", xs@_*) => MergeStrategy.discard
case "reference.conf" => MergeStrategy.concat
case _ => MergeStrategy.first
},
assembly / test := {} // skip unit test when build uber jar
)