A method and mechanisms for checkpointing objects, processes and other components of a multithreaded application program, based on the leader-follower strategy of semi-active or passive replication, where it is not possible to stop and checkpoint all of the threads of the object, process or other component simultaneously. In some situations, users may specify groups of computing nodes and optionally associated access policies for use in the managing of the communications for those groups, such as by specifying which source nodes are allowed to transmit data to particular destinations nodes. The backrest 1B includes a tear line at an upper portion thereof. The module restraint is configured to mate with a complementary shaped restraint on a mounting adapter. The reward may be distributed to the first subscriber if the second subscriber purchases the item based on the recommendation received from the first subscriber. The adhesion promoter comprises the product of mixing together a solution of a polymer or synthetic resin with an organophosphorus compound, and then mixing the mixture formed in with a titanium compound selected from a titanium halide, alkoxide, halo-alkoxide or a condensed titanium alkoxide or a mixture of more than one of these titanium compounds.