Abstract: A method, a resource manager, and a computer program are described for scheduling instances in a logical server, where each instance belongs to a class of instances, where each class is associated with a required service level objective (SLO). Based on determined margins between current SLOs and required SLOs, instances are sorted. If resources are not enough, an instance having a large margin may be pre-empted irrespective of the class. If available resources are sufficient for an instance having a small margin, this instance can be allocated resources. If the available resources do not suffice, it may be decided to pre-empt another instance to which resource are allocated, in order to free resources sufficient for the instance having the small margin. Accordingly, scheduling is performed for instances having various classes without violating the SLOs of the instances and such that resources are more efficiently used.

Abstract: A method, a resource manager, and a computer program are described for scheduling instances in a logical server, where each instance belongs to a class of instances, where each class is associated with a required service level objective (SLO). Based on determined margins between current SLOs and required SLOs, instances are sorted. If resources are not enough, an instance having a large margin may be pre-empted irrespective of the class. If available resources are sufficient for an instance having a small margin, this instance can be allocated resources. If the available resources do not suffice, it may be decided to pre-empt another instance to which resource are allocated, in order to free resources sufficient for the instance having the small margin. Accordingly, scheduling is performed for instances having various classes without violating the SLOs of the instances and such that resources are more efficiently used.

Abstract: This invention relates to a computing system, a fail-silent node for use in a computing system and a method of organizing information so that a number of microprocessors in a computing node, which are arranged to receive messages from other components in the computing system and to process the received messages so as to transmit the results of this processing to other components in the system, compare the results of their processing and send nothing out from the node unless either all the microprocessors in the mode produce identical results or more than half of the microprocessors in the node produce identical results. This is achieved by manipulating the order in which messages are processed by each microprocessor so as to ensure that each microprocessor in the node receives the same messages, orders these same messages so that messages within each microprocessor are processed in the same order, thus ensuring, if all the microprocessors are functioning correctly, that the same results are produced.