The messaging service 900 may comprise one or more sessions servers 912. The one or more session servers 912 may maintain session state of connected messaging clients.
The messaging service 900 may comprise one or more presence servers 914. The one or more presence servers 914 may maintain presence information for the messaging service 900. Presence information may correspond to user-specific information indicating whether or not a given user has an online messaging client and is available for chatting, has an online messaging client but is currently away from it, does not have an online messaging client, and any other presence state.
The messaging service 900 may comprise one or more push storage servers 916. The one or more push storage servers 916 may cache push requests and transmit the push requests to messaging clients. Push requests may be used to wake messaging clients, to notify messaging clients that a messaging update is available, and to otherwise perform server-side-driven interactions with messaging clients.
The messaging service 900 may comprise one or more group servers 918. The one or more group servers 918 may maintain lists of groups, add users to groups, remove users from groups, and perform the reception, caching, and forwarding of group chat messages.