MAINTAINING PERSISTENCE OF A MESSAGING SYSTEM

Methods, systems, and apparatus, including computer programs for receiving, from a first client device, a request for messages of a first channel of a plurality of channels starting at a position in the first channel, wherein each channel comprises a respective ordered plurality of messages stored in one or more respective buffers according to the order, each buffer having a respective time-to-live; receiving, from one of the second client devices, a response message comprising one or more messages of the first channel that are at or after the position in the order; and sending the messages tothe first client device. 本发明提供了包括用于从第客户端装置接收针对在多个通道中的第通道中的位置处开始的所述第通道的消息的请求的计算机程序的方法、系统和设备，其中各通道包括相应的有顺序的多个消息，所述多个消息根据所述顺序被存储在个或多个相应缓冲器中，各缓冲器具有相应存活时间；从所述第二客户端装置中的个第二客户端装置接收包括所述顺序中的位于该位置之处或之后的所述第通道中的个或多个消息的响应消息；将所述消息发送至所述第客户端装置。