Server management apparatus and server management method

[0053]FIG. 1 is a diagram showing a cluster system in accordance with an embodiment 1. This cluster system is generally made up of a server management apparatus 101, a group of physical servers 102 which are objects to be managed and each of which has a group of virtual servers 103, and a workload dispersion device 104, also known as load balancer. The load balancer 104 is communicably connected via a network 105 to client equipment 106.

[0054]The server management apparatus 101 has its function of executing scale-in / scale-out processing, and may be realizable by using a currently available standard computer. The server management apparatus 101 includes a memory 112, a central processing unit (CPU) 113, a communications device 114, a storage device 114 such as hard disk drive (HDD) or else, an input device 115, and a display device 116. The server management apparatus 101 is coupled to the physical server group 102, virtual server group 103 and load balancer 104 via communication devi

[0102]An embodiment 2 is the one that is similar to the server management apparatus 101 of the embodiment 1 with an additional means being provided therein, which is for selecting a physical server of the scale-out target by leveraging a degree of load variation similarity of each of a plurality of cluster systems at the time of scale-out judgment. The load variation similarity as used herein is a degree of coincidence of a cluster system-constituting virtual server number-increasing / decreasing time period and stay-constant time period and, further, virtual server number change rate at that time. In cluster systems which coincide with each other in the load variation similarity, migration is performed to a state which is simultaneously less or greater in cluster system-constituting virtual server number. To derive this load variation similarity through computation, a time period with the cluster system-constituting virtual server number staying constant and information of a virtual s

[0127]An embodiment 3 is the one that adds to the server management apparatus 101 of the embodiment 1 a means for performing migration of a virtual server(s) after execution of the scale-in processing to thereby execute virtual server workload consolidation, thus making it possible to turn off the power supply of a surplus physical server(s). As for the workload consolidation here, appropriate control is provided to execute this processing only when it is possible to power down a physical server by migration of a virtual server(s) thereto while preventing execution of any load consolidation with no power consumption reducing effect.

[0128]FIG. 10 is a diagram showing a cluster system in accordance with the embodiment 3. As shown in FIG. 10, respective software programs of a workload consolidation judgment unit 1001, workload consolidation target virtual server selection unit 1002 and workload consolidation execution unit 1003 are added to the storage device 111 of the server management