This document provides an overview of schedulers and timers in Akka. It discusses how schedulers allow tasks or messages to be run or sent to actors at defined points in the future, either single executions or periodically. It describes two types of scheduling delays - fixed-delay and fixed-rate execution. Timers are used specifically for scheduling within actors and ensure schedules continue if an actor restarts. The document demonstrates setting up single and periodic timers using the Timers trait and describes the actor lifecycle.

1. Presented By:
Purva Agrawal
Software Consultant
Schedulers and
Timers in Akka

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3. Agenda
01 Introduction to Akka Actors
02 Schedulers
04 Demo
Timers
03

4. Introduction to Akka Actors

5. ● Akka is a toolkit and runtime for building highly concurrent, distributed,
and fault-tolerant message-driven applications on the JVM.
● Akka is written in Scala.
● What is an Actor and ActorSystem?
● Message Passing

6. Schedulers

7. ● A scheduler is something that is provided by the actor system:
○ Allows to run a task or send a message to an actor
○ Be able to run some code at a defined point in the future
once or on a periodic basis
● Scheduling the message to be sent to an actor:
○ Single Execution Scheduler
○ Periodic Execution Scheduler
● Dependency
libraryDependencies += "com.typesafe.akka" %% "akka-actor-typed" %
"2.6.8"

8. ● Single Execution Scheduler
● Periodic Execution Scheduler

9. Akka Scheduler provides two types of scheduling delays:
● Fixed-delay execution
● Fixed-rate execution
What is Cancellable?
● This allows you to cancel something that has been
scheduled for execution.
Types of Delays

10. Timers

11. ● If the scheduling is done within an Actor, then the Actor Timers come into
picture.
● It takes care of the scheduling when the actor restarts.
● It is used to manage the lifecycle of scheduled messages especially when
the actor is restarted.
● Each timer has a key and can be replaced or cancelled.

12. ● Mix-in the akka.actor.Timers trait
● Use methods
– timers.startSingleTimer
– timers.startPeriodicTimer
● Name a timer by passing in a key (type Any)

13. Actor Life Cycle
So, here is a glimpse of how an Akka Actor Lifecycle works. The actor lifecycle begins as soon as
the actor is created.
The stages of an Akka Actor Lifecycle are as follows –
● preStart()
● Start
● Stop
● postStop()
● terminated

14. DEMO

15. Thank You !