Abstract: Technologies are described for cost based management of cache entries stored in a computer memory. In one example, a plurality of cache entries may be stored at a cache in a computer memory and the cache entries may have a cost measure associated with individual cache entries. A cost measure may represent a computing cost of an application to generate a cache entry. An incoming cache entry may be received at the cache, where the incoming cache entry has a cost measure associated with the incoming cache entry. In response to receiving the incoming cache entry, a cache entry that has a lower cost measure than the cost measure for other cache entries may be identified for eviction from the cache. The cache entry identified for eviction may be evicted from the cache, and the incoming cache entry may be written into the cache stored in the computer memory.

Abstract: Methods, systems, and computer-readable media for augmenting storage functionality using emulation of storage characteristics are disclosed. An access request for a data set is received. The access request is formatted according to a first protocol associated with a first data store, and the first data store is associated with first storage characteristics. The access request is translated into a translated access request. The translated access request is formatted according to a second protocol associated with a second data store, and the second data store is associated with second storage characteristics differing at least in part from the first storage characteristics. The translated access request is sent to the second data store. The translated access request is performed by the second data store on the data set using emulation of one or more of the first storage characteristics not included in the second storage characteristics.

Abstract: Modifications to caching performed between different services may be determined. A history of requests and responses between the different services may be obtained. The history may be evaluated to determine respective frequencies of parameters between the services. The frequencies of parameters may be evaluated to determine one or more modifications to caching among the different services. The modifications may be provided in order to be applied to change caching performance for subsequent requests.

Abstract: Methods, systems, and computer-readable media for augmenting storage functionality using emulation of storage characteristics are disclosed. An access request for a data set is received. The access request is formatted according to a first protocol associated with a first data store, and the first data store is associated with first storage characteristics. The access request is translated into a translated access request. The translated access request is formatted according to a second protocol associated with a second data store, and the second data store is associated with second storage characteristics differing at least in part from the first storage characteristics. The translated access request is sent to the second data store. The translated access request is performed by the second data store on the data set using emulation of one or more of the first storage characteristics not included in the second storage characteristics.

Abstract: Methods, systems, and computer-readable media for record-by-record live migration using segmentation are disclosed. Migration of a data set comprises, for a record in a segment being migrated, storing a first status indicating that the record is offline in a source data store. An instance of the record is stored in the destination data store, and a second status is stored to indicate that the record is online in the destination. The record is deleted from the source after the second status is stored. During the migration, a read request for the record is received and determined to be associated with the segment being migrated. A response to the read request is generated that comprises an authoritative instance of the record. The instance of the record in the destination is determined to represent the authoritative instance based (at least in part) on the first status and the second status.

Abstract: Methods, systems, and computer-readable media for augmenting storage functionality using emulation of storage characteristics are disclosed. An access request for a data set is received. The access request is formatted according to a first protocol associated with a first data store, and the first data store is associated with first storage characteristics. The access request is translated into a translated access request. The translated access request is formatted according to a second protocol associated with a second data store, and the second data store is associated with second storage characteristics differing at least in part from the first storage characteristics. The translated access request is sent to the second data store. The translated access request is performed by the second data store on the data set using emulation of one or more of the first storage characteristics not included in the second storage characteristics.

Abstract: Methods, systems, and computer-readable media for segmentation of maintenance on distributed systems are disclosed. A data set is partitioned according to a hash function into a plurality of segments. A maintenance activity is initiated on a first segment. During the maintenance activity, a first request to perform a first action on the data set is received. Based at least in part on determining that the first request is associated with the first segment using the hash function, the first action is performed using additional processing associated with the maintenance activity. During the maintenance activity, a second request to perform a second action on the data set is received. Based at least in part on determining that the second request is associated with a second segment using the hash function, the second action is performed without the additional processing associated with the maintenance activity.

Abstract: Methods, systems, and computer-readable media for transactionally consistent backup of partitioned storage are disclosed. Backup operations are initiated for a first and second partition of one or more data stores. The position of a first marker is determined in a first log associated with the first partition. The first log indicates a sequence of changes for the first partition. The position of a second marker is determined in a second log associated with the second partition. The second log indicates a sequence of changes for the second partition. The first or second marker is determined to violate a transactional boundary across the first and second partitions. A position of at least one of the markers is modified such that the markers do not violate the transactional boundary.

Abstract: Items within a data set can be redistributed to different partitions of a distributed data store according to modified hash values. A redistribution event may, in some embodiments, trigger the redistribution of a data set. Modified hash values for items in the data set may be generated according to a secondary hashing scheme to be used for identifying the location of a new partition to store the item instead of hash values based on current key values that identify a current partition that stores the item. Access can be provided to items based on the modified hash values to determine the new partition that stores the item after redistribution.

Abstract: Methods, systems, and computer-readable media for implementing augmenting storage functionality using composition are disclosed. A logical data store is determined based at least in part on storage requirements specified by a user. The logical data store comprises a composition of a plurality of storage adapters for a plurality of physical data stores including a first storage adapter for a first physical data store and a second storage adapter for a second physical data store. The first storage adapter and the second storage adapter are associated with different storage characteristics. A plurality of storage requests for the logical data store are received. Individual ones of the storage requests are routed to the first physical data store using the first storage adapter. Individual ones of the storage requests are routed to the second physical data store using the second storage adapter.

Abstract: A computing resource service provider may provide customers with access to various services provided by a set of service endpoints. During certain intervals of time increased network traffic may cause an increase in the consumption of computing resources of the set of service endpoints. A throttling trigger may be detected that may cause one or more routing devices to reroute network traffic to one or more lower tier routing devices. The lower tier routing devices may maintain throttling information and forward network traffic to the set of service endpoints.

Abstract: Sequence diagrams and executable stub modules are generated based on log data associated with a transaction. A sequence diagram generator receives data identifying a relationship between one or more requests and one or more replies stored in the log data. The sequence diagram describes the flow of events of any transaction described by the log data. A stub module comprising executable code in one or more programming languages may be automatically generated using the sequence diagram as input. The stub module may be executed to implement similar functionality of one or more components of the transaction described in the log data.