摘要:
A technique is described that reduces the complexity and resource consumption associated with performing record expiry in a distributed database system. In accordance with the technique, a record is checked to see if it has expired only when it has been accessed for a read or a write. If at the time of a read a record is determined to have expired, then it is not served. If at the time of a write a record is determined to have expired, then the write is treated as an insertion of a new record, and steps are taken to treat the insertion consistently with regard to the previous expired version. A background process is used to delete records that have not been written to or actively deleted by a client after expiration.
摘要:
A technique is described that reduces the complexity and resource consumption associated with performing record expiry in a distributed database system. In accordance with the technique, a record is checked to see if it has expired only when it has been accessed for a read or a write. If at the time of a read a record is determined to have expired, then it is not served. If at the time of a write a record is determined to have expired, then the write is treated as an insertion of a new record, and steps are taken to treat the insertion consistently with regard to the previous expired version. A background process is used to delete records that have not been written to or actively deleted by a client after expiration.
摘要:
An improved system and method for parallel retrieval of data from a distributed database is provided. A parallel interface may be provided for use by a cluster of client machine for parallel retrieval of partial results from parallel execution of a database query by a cluster of database servers storing a distributed database. A query interface may be augmented for inputting a database query and specifying the number of instances of parallel retrieval of results from query execution. To do so, a commercial query language may be augmented for sending a query request that may include a parameter specifying the database query and an additional parameter specifying the desired retrieval parallelism. The augmented query interface may return a list of retrieval point addresses for retrieving the partial results assigned to each of the retrieval point addresses from parallel execution of the database query.
摘要:
Methods and apparatuses are provided for dynamically reorganizing the data within a replicated database system. One method, for example, includes performing a split operation across a plurality of replicated databases with regard to an existing partition therein, wherein the existing partition comprises a plurality of data records and the two new partitions each include at least a portion of the plurality of data records, and allowing at least one type of access to the plurality of data records during the split operation.
摘要:
Methods and apparatuses are provided for dynamically reorganizing the data within a replicated database system. One method, for example, includes performing a split operation across a plurality of replicated databases with regard to an existing partition therein, wherein the existing partition comprises a plurality of data records and the two new partitions each include at least a portion of the plurality of data records, and allowing at least one type of access to the plurality of data records during the split operation.
摘要:
A system for maintaining a database. The system includes a storage unit for storing many tablets each tablet including multiple records. The tablet controller is configured to maintain the relationship between the tablet and the storage unit. The tablet controller tracks failures to access the storage unit and designates a new storage unit for each tablet based on a storage unit failure. A router is in communication with the tablet controller and configured to distribute messages from clients to the storage units thereby serving as a layer of indirection.
摘要:
A system for storing a distributed hash table. The system includes a storage unit, a tablet controller, a router, and a transaction bank. The storage unit has a plurality of tablets forming a hash table and each of the tablets includes multiple records. The tablet controller maintains a relationship between each tablet and the storage unit. The router hashes a record's key to determine the tablet associated with each record. Further, the router distributes messages from clients to the storage units based on the tablet-storage unit relationship thereby serving as a layer of indirection. The transaction bank propagates updates made in one record to all other replicas of the record.
摘要:
A system for a distributed database implementing a dynamic mastership strategy. The system includes a multiple data centers, each having a storage unit to store a set of records. Each data center stores its own replica of the set of records and each record includes a field that indicates which data center is assigned to be the master for that record. Since each of the data centers can he geographically distributed, one record may be more efficiently edited with the master being one geographic region while another record, possibly belonging to a different user, may be more efficiently edited with the master being located in another geographic region.
摘要:
A system, method, and computer program product is provided for publishing transcoded media content in response to publishing service requests from end users. A user request for media content is processed intelligently, either by directing the processing of the request to one of a set of transcoding servers so as to effectively balance the load among the servers, or by directing the processing of the request to an appropriate alternative means for satisfying the request. Transcoding tasks can be prioritized. In order to facilitate server selection, the current load on any particular transcoding server can be monitored in conjunction with a determination of the load to be created by a transcoding task. Transcoding can be performed on-demand or in a batch mode. Alternatively, a request can be satisfied by distributing media content that has already been transcoded and is resident in cache memory in anticipation of such requests.
摘要:
A system, method, and computer program product for publishing transcoded media content in response to publishing service requests from end users. A user request for media content, is processed intelligently, either by directing the processing of the request to one of a set of transcoding servers so as to effectively balance the load among the servers, or by directing the processing of the request to an appropriate alternative means for satisfying the request. Transcoding tasks can be prioritized. Moreover, the current load on any particular transcoding server can be monitored in conjunction with determination of the load to be created by a transcoding task, in order to facilitate server selection. Transcoding can be performed on-demand or in a batch mode. Alternatively, a request can be satisfied by distributing media content that has already been transcoded and is resident in cache memory in anticipation of such requests.