A computer implemented method of improving server coverage of a publish-subscribe cluster comprising using one or more hardware processors to execute one or more shared subscriptions hubs each adapted to retrieve shared subscriptions information from a cluster comprising multiple servers executing multiple messaging engines of a publish-subscribe service for forwarding messages to a plurality of subscribing clients, each message is associated with one or more of a plurality of topics, receive shared subscriptions requests for subscribing for one or more of the topics from distributed subscriptions client(s) applying shared subscriptions for the topic(s) through subscription group(s) comprising a subset of the subscribing clients, connect to preferred messaging engine(s) selected to improve server coverage of the subscription group(s) according to the shared subscriptions information to serve each of the plurality of shared subscriptions requests and forward messages associated with the topic(s) received from the selected messaging engine(s) to the subscription group(s).