Patent ID: 8775622
Filing Date: 2014-07-08
Classification: G06F

Abstract:
1. A network system, which is joined and left by a plurality of computers each of which is capable of being clustered with another computer, the network system comprising: a storage apparatus comprising a first table for storing clustering enabled/disabled information indicating whether a state of each computer is a clustering enabled state; the storage apparatus comprising a second table for storing addition easiness information indicating a probability value in adding another computer to a cluster which has already been formed by at least one of the plurality of computers, the probability value is a ratio of a required cluster size of the formed cluster to a total number of computers in the formed cluster, wherein one of the computers includes a cluster forming unit configured to form a cluster including the computer itself and another computer indicated as being under the clustering enabled state by the clustering enabled/disabled information on the first table, and updating the clustering enabled/disabled information on every computer included in the formed cluster to information indicating a clustering disabled state, and storing the addition easiness information on the formed cluster on the second table, and wherein the computer that formed the cluster includes a cluster growing unit configured to, when a candidate computer that is a candidate for addition to the cluster exists, determine whether the candidate computer is to be added to the cluster according to the addition easiness information recorded on the second table, wherein the cluster growing unit causes the probability value to vary with the addition of the candidate computer to the cluster as a trigger.