1. A computer-implemented method of criteria-based message publication control and feedback in a publish/subscribe messaging environment, comprising: receiving, at a message broker, a message published by a message publisher, the message having associated therewith a topic and classification criteria, the classification criteria specifying requirements for determining whether publication of the message is successful; consulting, by the message broker, a subscription registry to locate registered subscriptions of a plurality of message subscribers that have registered with the message broker to receive published messages having the topic, each of the registered subscriptions further specifying subscriber classification information pertaining to the topic; selecting, by the message broker from the located subscriptions, each of at least one of the located subscriptions for which the registered subscriber classification information matches the classification criteria associated with the message, wherein the registered subscriber classification information for at least one of the located subscriptions does not match the classification criteria associated with the message; identifying, for each of the at least one selected subscription, the subscriber that registered the selected subscription; sending the message, by the message broker, to the each identified subscriber; comparing, by the message broker, the subscriber classification information in the at least one selected subscription to the classification criteria associated with the message to determine whether the requirements specified in the classification criteria are met by the at least one selected subscription; and responsive to determining, by the comparing, that the requirements are not met, performing controlled failure handling, the controlled failure handling comprising: responsive to determining that a mode of failure handling applicable for the message indicates a warning mode, sending the message, by the message broker, to each of the message subscribers that registered one of the located subscriptions which was not selected by the selecting and warning the message publisher that publication of the message was not successful; and responsive to determining that the mode of failure handling indicates a failure mode, notifying the message publisher that publication of the message failed while omitting the sending of the message to each of the message subscribers that registered one of the located subscriptions which was not selected by the selecting.
1. A computer-implemented method of criteria-based message publication control and feedback in a publish/subscribe messaging environment, comprising: receiving, at a message broker, a message published by a message publisher, the message having associated therewith a topic and classification criteria, the classification criteria specifying requirements for determining whether publication of the message is successful; consulting, by the message broker, a subscription registry to locate registered subscriptions of a plurality of message subscribers that have registered with the message broker to receive published messages having the topic, each of the registered subscriptions further specifying subscriber classification information pertaining to the topic; selecting, by the message broker from the located subscriptions, each of at least one of the located subscriptions for which the registered subscriber classification information matches the classification criteria associated with the message, wherein the registered subscriber classification information for at least one of the located subscriptions does not match the classification criteria associated with the message; identifying, for each of the at least one selected subscription, the subscriber that registered the selected subscription; sending the message, by the message broker, to the each identified subscriber; comparing, by the message broker, the subscriber classification information in the at least one selected subscription to the classification criteria associated with the message to determine whether the requirements specified in the classification criteria are met by the at least one selected subscription; and responsive to determining, by the comparing, that the requirements are not met, performing controlled failure handling, the controlled failure handling comprising: responsive to determining that a mode of failure handling applicable for the message indicates a warning mode, sending the message, by the message broker, to each of the message subscribers that registered one of the located subscriptions which was not selected by the selecting and warning the message publisher that publication of the message was not successful; and responsive to determining that the mode of failure handling indicates a failure mode, notifying the message publisher that publication of the message failed while omitting the sending of the message to each of the message subscribers that registered one of the located subscriptions which was not selected by the selecting. 6. The method according to claim 1 , wherein the classification criteria associated with the message is specified as one or more rules, which together specify the requirements for the successful publication of the message.