ppacer

Ppacer is a DAG scheduler aiming to provide high reliability, high performance and minimal resource overhead.

This repository contains ppacer core Go packages.

Getting started

If you would like to run ppacer "hello world" example and you do have Go compiler in version >= 1.22, you can simply go get ppacer packages (in existing Go module)

go get github.com/ppacer/core@latest
go get github.com/ppacer/tasks@latest
go get github.com/ppacer/ui@latest

And then run the following program:

package main

import (
    "context"
    "time"

    "github.com/ppacer/core"
    "github.com/ppacer/core/dag"
    "github.com/ppacer/core/dag/schedule"
    "github.com/ppacer/tasks"
    "github.com/ppacer/ui"
)

const (
    schedulerPort = 9321
    uiPort        = 9322
)

func main() {
    ctx := context.Background()

    dags := dag.Registry{}
    dags.Add(printDAG("hello_world_dag"))

    go func() {
        ui.DefaultStarted(schedulerPort, uiPort)
    }()
    core.DefaultStarted(ctx, dags, schedulerPort)
}

func printDAG(dagId string) dag.Dag {
    //         t21
    //       /
    // start
    //       \
    //         t22 --> finish
    start := dag.NewNode(tasks.NewPrintTask("start", "hello"))
    t21 := dag.NewNode(tasks.NewPrintTask("t21", "foo"))
    t22 := dag.NewNode(tasks.NewPrintTask("t22", "bar"))
    finish := dag.NewNode(tasks.NewPrintTask("finish", "I'm done!"))

    start.Next(t21)
    start.Next(t22)
    t22.Next(finish)

    startTs := time.Date(2024, time.March, 11, 12, 0, 0, 0, time.Local)
    schedule := schedule.NewFixed(startTs, 10*time.Second)

    printDag := dag.New(dag.Id(dagId)).
        AddSchedule(&schedule).
        AddRoot(start).
        Done()
    return printDag
}

Detailed instructions and a bit more of explanations are presented here: ppacer/intro.

Development

Developers who use Linux or MacOS can simply run ./build.sh, to build packages, run tests and benchmarks.

Default log severity level is set to WARN. In case you need more details, you can use PPACER_LOG_LEVEL env variable, like in the following examples:

PPACER_LOG_LEVEL=INFO go test -v ./...

In case when you need to just debug a single test, you run command similar to the following one:

PPACER_LOG_LEVEL=DEBUG go test -v ./db -run=TestReadDagRunTaskSingle