Abstract: This disclosure describes, generally, methods and systems for implementing memory overcommit of virtual machines. The method includes establishing a plurality of virtual machines on a physical machine, broadcasting, from each of the plurality of virtual machines to a central scheduler, resource usage requirements, and then based at least in part on the resource usage requirements broadcasted from each of the plurality of virtual machines, determining a resource requirements schedule for each of the plurality of virtual machines. The method further includes receiving at least one resource request from at least one of the plurality of virtual machines, based on the resource requirements schedule, un-assigning resources from at least one of the plurality of virtual machines, and assigning the un-assigned resources to the at least one of the plurality of virtual machines which initiated the resource request.

Abstract: This disclosure describes, generally, methods and systems for implementing memory overcommit of virtual machines. The method includes establishing a plurality of virtual machines on a physical machine, broadcasting, from each of the plurality of virtual machines to a central scheduler, resource usage requirements, and then based at least in part on the resource usage requirements broadcasted from each of the plurality of virtual machines, determining a resource requirements schedule for each of the plurality of virtual machines. The method further includes receiving at least one resource request from at least one of the plurality of virtual machines, based on the resource requirements schedule, un-assigning resources from at least one of the plurality of virtual machines, and assigning the un-assigned resources to the at least one of the plurality of virtual machines which initiated the resource request.

Abstract: This disclosure describes, generally, methods and systems for implementing memory overcommit of virtual machines. The method includes establishing a plurality of virtual machines on a physical machine, broadcasting, from each of the plurality of virtual machines to a central scheduler, resource usage requirements, and then based at least in part on the resource usage requirements broadcasted from each of the plurality of virtual machines, determining a resource requirements schedule for each of the plurality of virtual machines. The method further includes receiving at least one resource request from at least one of the plurality of virtual machines, based on the resource requirements schedule, un-assigning resources from at least one of the plurality of virtual machines, and assigning the un-assigned resources to the at least one of the plurality of virtual machines which initiated the resource request.

Abstract: According to an aspect of the present invention, nodes for hosting of new virtual machines (VM) are selected according to approaches designed to reduce power consumption in a grid. In an embodiment, the approaches are designed to facilitate the possibility of freeing one or more nodes from hosting VMs to power down the nodes, thereby reducing power consumption. Thus, an example approach is based on provisioning a new VM on a node which currently (immediately prior to provisioning) has the maximum resource consumption. Another example approach is based on provisioning a new VM on a node which currently has small-sized VMs in terms of resource requirements. In yet another embodiment, the approach is based on provisioning a new VM on a node located in a geographical area having low power tariffs.

Abstract: An aspect of the present invention mitigates reduction in availability level during maintenance of nodes in a cluster. In one embodiment, on receiving an indication that a maintenance activity is to be performed on the cluster, a scaling out of the cluster is first performed to add some nodes having the maintenance activity already performed, followed by a scaling in of the cluster to remove some of the nodes in the cluster which do not yet have the maintenance activity performed. The scaling out is performed before any scaling in of the cluster such that the number of nodes available in the cluster after the scaling in is not less than the number of nodes in the cluster at the time of receiving the indication. Accordingly, the reduction in availability level (which is based on the number of nodes available) is mitigated.

Abstract: An aspect of the present invention reduces the recovery time for business organizations in case of disasters. In one embodiment, a disaster recovery system containing a primary site and a backup site (implemented as a cluster) is maintained. Application instances are executed in both the primary site and the backup site, with the number of instances executed on the backup site being fewer than that executed on the primary site. During normal operation, user requests received are processed using only the instances executing in the primary site, while the instances executing in the backup site are used in a standby state. On identifying that a disaster has occurred, the user requests received immediately after identification of the disaster are processed using only the instances executing in the backup site. The cluster at the backup site is then scaled out to add application instances until a desired level/percentage is achieved.

Abstract: Reducing access time for data in a file system when seek requests are received ahead of access requests. In one embodiment, an operating system providing access to the file system receives a seek request (from a user application) indicating an identifier of a file and a location within the file at which a data is sought to be accessed. In response, the operating system computes the offset of a disk block containing the location (thereby the data that is sought to be accessed). On receiving an access request (after the seek request from the same user application) indicating an operation to be performed on the data, the operating system executes the operation on the data using the pre-computed offset of the disk block. The computation of the disk block is performed before the access request is received thereby reducing the time required to process the access request.

Abstract: This disclosure describes, generally, methods and systems for implementing memory overcommit of virtual machines. The method includes establishing a plurality of virtual machines on a physical machine, broadcasting, from each of the plurality of virtual machines to a central scheduler, resource usage requirements, and then based at least in part on the resource usage requirements broadcasted from each of the plurality of virtual machines, determining a resource requirements schedule for each of the plurality of virtual machines. The method further includes receiving at least one resource request from at least one of the plurality of virtual machines, based on the resource requirements schedule, un-assigning resources from at least one of the plurality of virtual machines, and assigning the un-assigned resources to the at least one of the plurality of virtual machines which initiated the resource request.

Abstract: According to an aspect of the present invention, nodes for hosting of new virtual machines (VM) are selected according to approaches designed to reduce power consumption in a grid. In an embodiment, the approaches are designed to facilitate the possibility of freeing one or more nodes from hosting VMs to power down the nodes, thereby reducing power consumption. Thus, an example approach is based on provisioning a new VM on a node which currently (immediately prior to provisioning) has the maximum resource consumption. Another example approach is based on provisioning a new VM on a node which currently has small-sized VMs in terms of resource requirements. In yet another embodiment, the approach is based on provisioning a new VM on a node located in a geographical area having low power tariffs.

Abstract: An aspect of the present invention reduces the recovery time for business organizations in case of disasters. In one embodiment, a disaster recovery system containing a primary site and a backup site (implemented as a cluster) is maintained. Application instances are executed in both the primary site and the backup site, with the number of instances executed on the backup site being fewer than that executed on the primary site. During normal operation, user requests received are processed using only the instances executing in the primary site, while the instances executing in the backup site are used in a standby state. On identifying that a disaster has occurred, the user requests received immediately after identification of the disaster are processed using only the instances executing in the backup site. The cluster at the backup site is then scaled out to add application instances until a desired level/percentage is achieved.

Abstract: An aspect of the present invention mitigates reduction in availability level during maintenance of nodes in a cluster. In one embodiment, on receiving an indication that a maintenance activity is to be performed on the cluster, a scaling out of the cluster is first performed to add some nodes having the maintenance activity already performed, followed by a scaling in of the cluster to remove some of the nodes in the cluster which do not yet have the maintenance activity performed. The scaling out is performed before any scaling in of the cluster such that the number of nodes available in the cluster after the scaling in is not less than the number of nodes in the cluster at the time of receiving the indication. Accordingly, the reduction in availability level (which is based on the number of nodes available) is mitigated.

Abstract: Reducing access time for data in a file system when seek requests are received ahead of access requests. In one embodiment, an operating system providing access to the file system receives a seek request (from a user application) indicating an identifier of a file and a location within the file at which a data is sought to be accessed. In response, the operating system computes the offset of a disk block containing the location (thereby the data that is sought to be accessed). On receiving an access request (after the seek request from the same user application) indicating an operation to be performed on the data, the operating system executes the operation on the data using the pre-computed offset of the disk block. The computation of the disk block is performed before the access request is received thereby reducing the time required to process the access request.