In a publish/subscribe data processing broker network having a plurality of
broker data processing apparatuses, each of which has an input for
receiving published messages directly from a publisher application and/or
receiving subscription data directly from a subscriber application, and
each of which having a means for receiving a published message on a first
topic and assigning a broker-specific sequence number to the received
message; a first broker apparatus has: a software unit for determining a
failure of a neighboring broker apparatus which has provided published
messages on the first topic to the first broker apparatus; and a software
unit for sending historic resubscriptions with respect to the first topic
to each antecedent broker apparatus of the failed neighboring broker
apparatus by using the broker-specific sequence number corresponding to
each antecedent broker apparatus.