Abstract: In one embodiment, a service receives a one or more digests to verify a plurality of requests that were performed by a request handler for one or more clients. The digests summarize processing of the plurality of requests using a first contract. The information for the one or more digests is stored in a plurality of blocks in a distributed ledger. A second contract is executed to verify the processing of the plurality of requests. The second contract generates a first set that stores states for reads of values from the data store; generates a second set that stores states for values written to the data store, and verifies the processing by checking states in the first set are a subset of states in the second set.

Abstract: Systems, methods, and computer-executable instructions for reducing amortized computational costs for a query that includes receiving at least two indexes for elements stored in an n-element database. The n-element database is encoded into at least three buckets. Each element is stored within at least two buckets. Each bucket stores a proper subset of the n-elements. For each of the two indexes, a bucket is determined to retrieve the element at the index. The determined buckets are queried to retrieve the elements. The elements at the indexes are retrieved based on the querying the determined buckets.

Abstract: In one embodiment, a service receives a one or more digests to verify a plurality of requests that were performed by a request handler for one or more clients. The digests summarize processing of the plurality of requests using a first contract. The information for the one or more digests is stored in a plurality of blocks in a distributed ledger. A second contract is executed to verify the processing of the plurality of requests. The second contract generates a first set that stores states for reads of values from the data store; generates a second set that stores states for values written to the data store, and verifies the processing by checking states in the first set are a subset of states in the second set.

Abstract: Systems, methods, and computer-executable instructions for reducing amortized computational costs for a query that includes receiving at least two indexes for elements stored in an n-element database. The n-element database is encoded into at least three buckets. Each element is stored within at least two buckets. Each bucket stores a proper subset of the n-elements. For each of the two indexes, a bucket is determined to retrieve the element at the index. The determined buckets are queried to retrieve the elements. The elements at the indexes are retrieved based on the querying the determined buckets.

Abstract: Resource control for virtual datacenters is described, for example, where a plurality of virtual datacenters are implemented in a physical datacenter to meet guarantees. In examples, each virtual datacenter specifies a plurality of different types of resources having throughput guarantees which are met by computing, for individual flows of the virtual data centers implemented in the physical datacenter, a flow allocation. For example, a flow allocation has, for each of a plurality of different types of physical resources of the datacenter used by the flow, an amount of the physical resource that the flow can use. A flow is a path between endpoints of the datacenter along which messages are sent to implement a service. In examples, the flow allocations are sent to enforcers in the datacenter, which use the flow allocations to control the rate of traffic in the flows.