Asynchronous transfer of state information between continuous query plans
AssigneeMicrosoft Corporation
InventorsBadrish Chandramouli, Jonathan David Goldstein, Peter Alfred Zabback, David Eugene Maier, Di Wang
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Abstract
Described herein are technologies pertaining to migrating state information of operators in a first continuous query plan to a second continuous query plan in an asynchronous manner, such that the first continuous query plan need not cease executing during the migrating of the state information. State information pertaining to stateful operators, such as join operators, is migrated from the first continuous query plan to the second continuous query plan by way of a transformation plan. State matching is utilized to generate the transformation plan.
Claims20
A method, comprising:
- receiving a first continuous query plan, wherein a continuous query plan is a logical representation of a query, wherein the first continuous query plan comprises a first plurality of operators that continuously perform processing operations on temporal events, at least one temporal event in the temporal events comprising a time window during which the at least one temporal event contributes to an output of the first continuous query plan, the temporal events further comprising at least one revision event, the at least one revision event modifying the time window of the at least one temporal event;
- receiving a second continuous query plan, wherein the second continuous query plan comprises a second plurality of operators that are configured to continuously perform processing operations on the temporal events, wherein the second continuous query plan is logically equivalent to the first continuous query plan;
- and
- using a processor to automatically migrate, in an asynchronous manner, state information of at least one operator in the first plurality of operators to the second continuous query plan.
A system comprising a plurality of components that are executable by a processor, the components comprising:
- a receiver component that receives a first continuous query plan and a second continuous query plan, wherein the first continuous query plan and the second continuous query plan are configured to execute continuously over a data stream that comprises temporal events, wherein outputs of the first continuous query plan and the second continuous query plan are logically equivalent, and wherein the first continuous query plan comprises a first plurality of operators that perform processing operations on events in the data stream and the second continuous query plan comprises a second plurality of operators that are configured to perform processing operations on events in the data stream;
- and
- a migrator component that causes state information corresponding to the plurality of operators in the first continuous query plan to be asynchronously migrated to the second continuous query plan.
A computing device comprising a computer-readable memory, the computer-readable memory comprising instructions that, when executed by a processor, cause the processor to perform acts comprising:
- receiving an input data stream, wherein the input data stream comprises a plurality of temporal events;
- executing a first continuous query plan over the input data stream to generate an output data stream, wherein the first continuous query plan comprises a plurality of operators that perform processing operations on events in the input data stream, wherein at least one operator in the plurality of operators is a stateful operator;
- and
- causing a migrator event to be received by the at least one stateful operator, wherein responsive to receiving the migrator event the at least one stateful operator commences migrating state information corresponding thereto to a second continuous query plan, wherein the first continuous query plan continues to produce the output stream while the at least one stateful operator migrates the state information corresponding thereto to the second continuous query plan.
Dependencies are inferred from the claim text.