Scheduling a Future Agent Invocation (Scala)

Overview

A scheduled invocation enqueues a method call on the target agent to be executed at a specific future time. The call returns immediately; the target agent processes it when the scheduled time arrives.

Usage

Each method on the remote proxy has a .scheduleAt(when) method that enqueues the call for the given time:

import golem.Datetime
 
val counter = CounterAgentClient.get("my-counter")
 
// Schedule increment to run 5 seconds from now
counter.increment.scheduleAt(Datetime.afterSeconds(5))
 
// Schedule with arguments — method params first, then when
val reporter = ReportAgentClient.get("daily")
reporter.generateReport.scheduleAt(
  "summary",
  when = Datetime.afterSeconds(3600) // 1 hour from now
)

Datetime Helper

The golem.Datetime type provides helper methods:

import golem.Datetime
 
Datetime.afterSeconds(60)     // 60 seconds from now
Datetime.afterSeconds(3600)   // 1 hour from now

Cancelable Variant

Every method also has a scheduleCancelableAt variant that returns a Future[CancellationToken]. Call .cancel() on the token to prevent the scheduled invocation from firing:

import golem.runtime.rpc.CancellationToken
 
val token: CancellationToken = Await.result(
  counter.increment.scheduleCancelableAt(Datetime.afterSeconds(60)),
  Duration.Inf
)
 
// Later, to cancel the pending invocation:
token.cancel()

Use Cases

• Periodic tasks: Schedule the next run at the end of each invocation
• Delayed processing: Process an order after a cooling-off period
• Reminders and notifications: Send a reminder at a specific time
• Retry with backoff: Schedule a retry after a delay on failure