分布式任务调度
Elastic-Job XXL-Job Quartz

Temporal
the open source platform for orchestrating highly reliable, mission-critical applications at scale
orchestrate  编排

SDKs  （Java go php ...）
  Write Workflows and Activities, run Workers and embed Temporal Clients in your applications.
Temporal  Cluster
Dev Tools  (webUI  tctl )
  Tools to manage Workflow Execution lifecycles, manage your Cluster, debug your application, and more.
  
The Temporal CLI (tctl) is a command-line tool that you can use to interact with a Temporal Cluster. 
It can perform Namespace operations (such as register, update, and describe) 
and Workflow operations (such as start Workflow, show Workflow History, and Signal Workflow).
  
  
几种角色
Activity Workflow Workers TemporalServer CLI Web SDK

Activity	一段可运行代码（function） 不限制开发语言 提供了各种语言的SDK 
Workflow	Activity的集合，多个Activity可以构成一个Workflow，调度的最小单位
Workers	    不同语言写的Workflow 注册到对应语言的Worker中，Worker是代码的真正执行者
Temporal server 	管理注册到自己的Workers，向Workers下发任务，监听任务状态等
CLI or SDK	任务的发起者、监控任务进度等
Web	负责任务的监控、查询等


CLI or SDK  负责启动某个Workflow
Temporal server  把请求调度到某个Worker
Worker   负责执行任务


Activity 限制很少
Workflow  不建议和外部系统交互（读写文件 访问网络）等


定时任务
周期性任务
延时任务

延时1小时向用户发送短信和邮件

编写Activity代码
编写Workflow 代码
启动 Worker
启动 TemplateServer
发起任务


// 连接到 Temporal Server，注册自己
c, err := client.NewClient(client.Options{})
w := worker.New(c, app.TaskQueue, worker.Options{})
w.RegisterWorkflow(app.SendMessageWorkflow)
w.RegisterActivity(app.SendMessage)
w.RegisterActivity(app.SendEmail)
// Start listening to the Task Queue
err = w.Run(worker.InterruptCh())



参考资料

Server Intro
https://docs.temporal.io/docs/server/introduction

Temporal Core Concepts
https://docs.temporal.io/docs/temporal-explained/introduction

https://docs.temporal.io/docs/concepts/

Temporal architecture deep dive
https://docs.temporal.io/blog/workflow-engine-principles/


https://github.com/temporalio/temporal
https://docs.temporal.io/