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docs/source/en/basics/objects.md

@@ -270,6 +270,22 @@ We can get it via `ctx.coreLogger`, the difference between the Context Logger is
 
 We can get them via `this.logger` in Controller and Service instance, they are essentially a Context Logger, but additional file path will be added to logs, easy to locate the log print location.
 
+## Subscription
+
+Subscription is the model for subscribing, including consumer in message broker or schedule.
+
+The base class of Subscription is exported by egg.
+
+```js
+const Subscription = require('egg').Subscription;
+class Schedule extends Subscription {
+  // This method should be implemented
+  * subscribe() {}
+}
+```
+
+[Schedule](./schedule.md) is implemented using the model，also recommend the plugin for message broker.
+
 [Koa]: http://koajs.com
 [Koa.Application]: http://koajs.com/#application
 [Koa.Context]: http://koajs.com/#context

docs/source/zh-cn/basics/objects.md

@@ -270,6 +270,22 @@ module.exports = {
 
 我们可以在 Controller 和 Service 实例上通过 `this.logger` 获取到它们，它们本质上就是一个 Context Logger，不过在打印日志的时候还会额外的加上文件路径，方便定位日志的打印位置。
 
+## Subscription
+
+Subscription 是一种订阅模型，消息中间件的消费者或调度任务都属于这种模式。
+
+可以通过以下方式来引用 Subscription 基类：
+
+```js
+const Subscription = require('egg').Subscription;
+class Schedule extends Subscription {
+  // 是需要实现此方法
+  * subscribe() {}
+}
+```
+
+[定时任务](./schedule.md)使用这种模式实现，也建议使用此模型实现消息中间件。
+
 [Koa]: http://koajs.com
 [Koa.Application]: http://koajs.com/#application
 [Koa.Context]: http://koajs.com/#context