Abstract: A method and system for affinity management in a distributed computer system are provided in which a plurality of addressing entities (311-315) need to be balanced across a plurality of service providers (301-304) whilst maintaining group affinities within the addressing entities. An identifier is provided for each of a plurality of addressing entities, wherein the identifier for each member of a group of addressing entities with an affinity is the same group identifier. A list is provided of service providers which are available to be addressed by an addressing entity to provide an instance of a service. The distribution of addressing entities to service providers is managed by an algorithm. The algorithm includes: applying (205) a hash function to the identifier of an addressing entity to obtain a standard integer; dividing (206) the standard integer by the number of service providers and obtaining the modulus; and selecting (207) a service provider by reference to the modulus.

Abstract: A method for determining whether a plurality of participants who are participating in a distributed transaction have registered their intention to commit their part of the transaction with a transaction manager, the method comprising the steps of: receiving a message from a participant, the message comprising a character sequence identifying the participant and the part of the transaction which the participant is processing; analysing the character sequence to determine whether the character sequence further comprises an identifier for identifying whether a subsequent message is to be received by a second participant; and in dependence on the identifier identifying that there are no further subsequent messages to be received, informing each of the participants to commit their part of the transaction.