International Business Machines Corporation

Snap Inc.

Andrew David Banks

Gavin David Beardall

Ian C Vanstone

Stephen James Hobson

Adrian David Dick

Brian Clive Homewood

Daniel Noel Millwood

Richard Scott Maxwell

Ian Charles Vanstone

Martyn Honeyford

In response to receipt of a request message from a requester, a reply message is created. The reply message includes a message identifier of the request message copied from the received request message. The reply message is published to each of a group of replicated message queues. The reply message is identifiable by the requester using the copied message identifier of the request message on any one of the group of replicated message queues prior to being consumed by the requester.

Message delivery in messaging networks

A method and computer program product is disclosed for managing a message broker and subscriber application programs in a publish/subscribe messaging system so as to maintain the state of the subscriber application program on the broker subscriber application program.

Managing a message subscription in a publish/subscribe messaging system

A method and system for message delivery in messaging networks is provided. The system provides a group of replicated queues for messages that are operable to be identified by an application before a message is read. The group of replicated queues are defined in association with a group of message managing systems, where a message is sent to each of the group of replicated queues to be accessible using any one of the group of message managing systems. The method includes creating a message including a unique identifier, and sending the message to each of a group of replicated queues with the message identifiable by the unique identifier information prior to the message being consumed.

A publish/subscribe messaging network in which a distributed set of publish/subscribe brokers comprises a first subset of publish/subscribe brokers, each arranged to store proxy subscription information for the whole of the distributed set of brokers; and a second subset of publish/subscribe brokers, each configured to send subscription information for local subscribers to one or more brokers within the first subset of publish/subscribe brokers, and configured to request, from a broker within the first subset of brokers, proxy subscription information following receipt of a message.

Scalable publish/subscribe messaging systems and methods

Disclosed is a method comprising steps of: a broker software application receiving a first published message on a topic from a publisher application and storing the first published message in a local storage location along with an indicator which indicates that the first published message originated from a publisher application that is local to the broker software application; the broker software application receiving a second published message on the topic from another broker software application and storing the second published message in the local storage location in place of the previously stored first published message, along with an indicator which indicates that the second published message originated from a publisher application that is remote to the broker software application; and the broker software application delivering the second published message, from the local storage location, to a requesting subscriber application which has requested a last retained publication message on the topic.

Retained publish/subscribe system

In a method of controlling a network of interconnected publish/subscribe message brokers for routing publications from a plurality of publishers to interested subscribers, each message broker is arranged to receive publications from publishers both directly and via other brokers and to receive subscriptions and unsubscriptions from subscribers and other brokers for publications meeting predefined criteria identified in the subscriptions or unsubscriptions. Each broker creates and manages a list correlating subscribers with the predefined criteria. It then matches received publications with the subscription list and forwards publications which match listed subscriptions which are in an active state to interested subscribers and interested other brokers in the list. Also, in response to received subscriptions and unsubscriptions, each broker generates and forwards proxy subscriptions and proxy unsubscriptions to other brokers. Each broker establishes a retention period for subscriptions. Then, in response to receipt of an unsubscription from a subscriber or a proxy unsubscription from another broker, it retains the corresponding subscription in a retained state for the retention period. During the retention period, matching publications will not be forwarded to the subscriber or other broker and no proxy unsubscriptions will be forwarded to other brokers. A new subscription for the same matching publications as the retained subscription during the retention period causes a reversion of the retained subscription to its active state. Propagation of proxy subscriptions and unsubscriptions is thus reduced in dependence on the duration of the retention period.

Limiting proxy subscription propagation in a publish/subscribe message broker network

When a new broker is connected to a network, a loop detection message is sent over the new connection created by the new broker. The loop detection message includes topics. At each receiving broker, topics that cannot be propagated to a neighbor broker are removed. If the loop detect message contains no topics, the loop detect message is not propagated further. If the loop detection message returns to the new broker, a loop is detected.

Topic based loop detection in a publish/subscribe network

A data processing apparatus for carrying out workload management with respect to a group of servers in an asynchronous client/server computing system, has: a device for receiving a work request from a client application; a device for consulting availability data concerning the group of servers and for selecting a particular server in the group to be used to satisfy the received work request on the basis of the consulted availability data, where the consulted availability data is always used in its present state when the work request is received, irrespective of whether availability data has been received for each server in the group, in order to select a server from the group; and a device for placing the received work request in a transmission queue where it awaits transmission to the particular server in the group.

Workload management in an asynchronous client/server computer system

A method, for use in a two phase commit protocol, of reducing the number of agents writing to a log and the number of points in a transaction at which the log must guarantee the durability of the data is disclosed. If all of the agents involved in a transaction have access to the same log and if in a network it is relatively expensive to send a message, but little penalty for sending a long message compared to a short one, then improved performance can be obtained by sending both the data to be written to the log and the request commit flows in the same communications buffer.

Growing community of inventors

Romsey, United Kingdom

Andrew David Banks