Vmware, Inc.

Preeti Kota

Oleg Zaydman

Yanping Cao

Pratik Kapadia

James Chang

A synchronization process for virtual-machine images (and other segmented files) provides for generating a 'delta' bitmap indicating which segments (e.g., clusters) of a first virtual-machine image were changed to obtain a second (e.g., updated) virtual-machine image on a source node. The delta bitmap can be applied to the second-virtual-machine image to generate a delta file. The delta file can be sent along with the delta bitmap to a target node that already has a copy of the first virtual-machine image. The transferred delta bitmap and delta file can then be used on the target node to generate a replica of the second virtual-machine image, thereby effecting synchronization. In variations, different bitmaps and delta files can be transferred to optimize the synchronization process.

Virtual machine image file synchronization using delta bitmaps and delta files

A cuckoo cache has plural buckets of plural cells each. The cells within a bucket are ranked to approximate relative usage recency. New items can be inserted into empty cells; when a bucket is full, room for a new item can be made by laterally transferring an older item to an alternative bucket. When empty cells and lateral transfers are unavailable, an item is selected for eviction based on the usage recency rank of the containing cell. When a match is found, depending on the embodiment, the hit item can be promoted within its bucket, to its alternative bucket, or to a separate tier of the cuckoo cache. The items can be key-value pairs. No metadata is required to track usage recency so that the cuckoo cache can be a very space efficient tool for finding cached values by their keys.

Cuckoo caching

A distributed computer system and method for synchronizing content libraries in replication groups uses a synchronization control signal that is transmitted to a subscribed content library management module of each subscribed content library in a replication group from a content library management module of the master content library in the replication group to initiate a synchronization procedure. Using metadata of at least one consumable software item from the master content library, contents of a subscribed content library in the replication group are modified to synchronize its contents to the contents of the master content library.

Replication groups for content libraries

A coordinated multi-cast content distribution process is used to distribute content, e.g., files, from a source node of a network to target nodes of the network. A minimum spanning tree is identified for the network based on costs of edges connecting the nodes. The minimum spanning tree includes the source node and all target nodes; the minimum spanning tree distinguishes leaf target nodes from non-leaf target nodes. Content parts are moved along the spanning tree in an iterative process in which, for each iteration, the highest-cost leaf nodes are identified and content parts are moved toward the identified leaf nodes. This process reduces avoids network congestion and reduces the total bandwidth consumption required to supply the content to all target nodes.

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Sunnyvale, CA, United States of America

Preeti Kota