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doc/DESIGN_DOC.md

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 ### 3.3 Model Online Reloading     
 
 In order to ensure the availability of services, the model needs to be hot loaded without service interruption. Paddle Serving supports this feature and provides a tool for monitoring output models to update local models. Please refer to [Hot loading in Paddle Serving](HOT_LOADING_IN_SERVING.md) for specific examples.

doc/DESIGN_DOC_CN.md

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 ### 3.3 模型热加载
 
 为了保证服务的可用性，需要在服务不中断的情况下对模型进行热加载。Paddle Serving对该特性进行了支持，并提供了一个监控产出模型更新本地模型的工具，具体例子请参考[Paddle Serving中的模型热加载](HOT_LOADING_IN_SERVING_CN.md)。