Redis – Vapor 4 Scheduled Jobs With Heroku

I have a Vapor 4 application where I’m using queues to create a scheduled job. This particular test job just prints logs every five minutes. When I run the project locally everything works as expected. However, when I deploy to Heroku things start misbehaving. According to the Heroku logs, it looks like this job gets fired multiple times every five minutes. It also appears to have just stopped randomly and no longer fires. The logs say "Process exited with status 0".

Am I missing something when deploying to Heroku? How can I get the same functionality that I am seeing locally?

I have included a screenshot of all logs below as well as the contents of my procfile and any relevant code.

Update: I changed my Heroku plan from "free" to "hobby" and that stopped the server from stopping. The free plan goes to sleep after a short time and that was causing my background worker to terminate. I’m still having the issue with duplications though.

public func configure(_ app: Application) throws {
    
    if let databaseURL = Environment.get("DATABASE_URL"), var postgresConfig = PostgresConfiguration(url: databaseURL) {
        postgresConfig.tlsConfiguration = .forClient(certificateVerification: .none)
        app.databases.use(.postgres(
            configuration: postgresConfig
        ), as: .psql)
    }
    
    //MARK: Migrations
    //...
    
    // MARK: Queue and Jobs
    let testJob = TestJob(app: app)

    try app.queues.use(.redis(url: "redis://127.0.0.1:6379"))
    
    for i in stride(from: 0, to: 60, by: 5){
        let minutes = ScheduleBuilder.Minute(integerLiteral: i)
        app.queues.schedule(testJob).hourly().at(minutes)
    }

    try app.queues.startScheduledJobs()

    // MARK: Register Routes
    try routes(app)
}

struct TestJob: ScheduledJob {
    let app: Application
    
    
    func run(context: QueueContext) -> EventLoopFuture<Void> {
        let formatter = DateFormatter()
        
        formatter.dateStyle = .medium
        formatter.timeStyle = .long
        print("n********* Test job: (formatter.string(from: Date())) *********")
        
        return context.eventLoop.makeSucceededVoidFuture()
    }
}

Profile

web: Run serve --env production --hostname 0.0.0.0 --port $PORT
worker: Run queues --scheduled