1. A computer-implemented method comprising: transmitting, by a client to a server, a single request for notifications based on a request/response protocol, wherein the server is configured to receive different types of notifications for the client from multiple data sources; connecting to the server via a communications pipe opened by the server in response to the single request for notifications; receiving aggregated notifications pushed by the server via the communications pipe as chunks of a holding thread, wherein the holding thread obtains exclusive use of the communication pipe for pushing the chunks of the holding thread to the client, locks out acquiring threads seeking use of the communications pipe to transmit notifications for the client included in the acquiring threads, and drains the notifications for the client from the acquiring threads through the communications pipe as chunks of the holding thread; interpreting, by the client, the chunks of the holding thread as multiple responses to the single request for notifications; and distributing the aggregated notifications to a user interface.