Gores

An asynchronous job execution system based on Redis

Installation

Get the package

$ go get github.com/wang502/gores/gores

Import the package

import "github.com/wang502/gores/gores"

Usage

Start local Redis server

$ git clone git@github.com:antirez/redis.git
$ cd redis
$ ./src/redis-server

Configuration

Add a config.json in your project folder

{
  "RedisURL": "127.0.0.1:6379",
  "RedisPassword": "mypassword",
  "BlpopMaxBlockTime" : 1,
  "MaxWorkers": 2,
  "Queues": ["queue1", "queue2"],
  "DispatcherTimeout": 5,
  "WorkerTimeout": 5
}

• RedisURL: Redis server address. If you run in a local Redis, the dafault host is 127.0.0.1:6379
• RedisPassword: Redis password. If the password is not set, then password can be any string.
• BlpopMaxBlockTime: Blocking time when calling BLPOP command in Redis.
• MaxWorkers: Maximum number of concurrent workers, each worker is a separate goroutine that execute specific task on the fetched item.
• Queues: Array of queue names on Redis message broker.
• DispatcherTimeout: Duration dispatcher will wait to dispatch new job before quitting.
• WorkerTimeout: Duration worker will wait to process new job before quitting.

Initialize config

configPath := flag.String("c", "config.json", "path to configuration file")
flag.Parse()
config, err := gores.InitConfig(*configPath)

Enqueue job to Redis queue

A job is a Go map. It is required to have several keys:

• Name: name of the item to enqueue, items with different names are mapped to different tasks.
• Queue: name of the queue you want to put the item in.
• Args: the required arguments that you need in order for the workers to execute those tasks.
• Enqueue_timestamp: the Unix timestamp of when the item is enqueued.

gores := gores.NewGores(config)
job := map[string]interface{}{
  "Name": "Rectangle",
  "Queue": "TestJob",
  "Args": map[string]interface{}{
                "Length": 10,
                "Width": 10,
          },
  "Enqueue_timestamp": time.Now().Unix(),
}

err = gores.Enqueue(job)
if err != nil {
	log.Fatalf("ERROR Enqueue item to Gores")
}

$ go run main.go -c ./config.json -o produce

Define tasks

package tasks

// task for item with 'Name' = 'Rectangle'
// calculating the area of an rectangle by multiplying Length with Width
func CalculateArea(args map[string]interface{}) error {
    var err error

    length := args["Length"]
    width := args["Width"]
    if length == nil || width == nil {
        err = errors.New("Map has no required attributes")
        return err
    }
    
    fmt.Printf("The area is %d\n", int(length.(float64)) * int(width.(float64)))
    return err
}

Launch workers to consume items and execute tasks

tasks := map[string]interface{}{
              "Item": tasks.PrintItem,
              "Rectangle": tasks.CalculateArea,
         }
gores.Launch(config, &tasks)

$ go run main.go -c ./config.json -o consume

The output will be:

The rectangle area is 100

Info about processed/failed job

gores := gores.NewGores(config)
if gores == nil {
    log.Fatalf("gores is nil")
}

info, err := gores.Info()
if err != nil {
  log.Fatal(err)
}

for k, v := range info {
    switch v.(type) {
    case string:
      fmt.Printf("%s : %s\n", k, v)
    case int:
      fmt.Printf("%s : %d\n", k, v)
    case int64:
      fmt.Printf("%s : %d\n", k, v)
    }
}

The output will be:

Gores Info:
queues : 2
workers : 0
failed : 0
host : 127.0.0.1:6379
pending : 0
processed : 1

Contribution

Please feel free to suggest new features. Also open to pull request!