Abstract
Computing aggregates over windows is at the core of virtually every stream processing job. Typical stream processing applications involve overlapping windows and, therefore, cause redundant computations. Several techniques prevent this redundancy by sharing partial aggregates among windows. However, these techniques do not support out-of-order processing and session windows. Out-of-order processing is a key requirement to deal with delayed tuples in case of source failures such as temporary sensor outages. Session windows are widely used to separate different periods of user activity from each other. In this paper, we present Scotty, a high throughput operator for window discretization and aggregation. Scotty splits streams into non-overlapping slices and computes partial aggregates per slice. These partial aggregates are shared among all concurrent queries with arbitrary combinations of tumbling, sliding, and session windows. Scotty introduces the first slicing technique which (1) enables stream slicing for session windows in addition to tumbling and sliding windows and (2) processes out-of-order tuples efficiently. Our technique is generally applicable to a broad group of dataflow systems which use a unified batch and stream processing model. Our experiments show that we achieve a throughput an order of magnitude higher than alternative state-of-The-Art solutions.
Original language | English |
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Title of host publication | Proceedings - IEEE 34th International Conference on Data Engineering, ICDE 2018 |
Publisher | Institute of Electrical and Electronics Engineers (IEEE) |
Pages | 1304-1307 |
Number of pages | 4 |
ISBN (Electronic) | 9781538655207 |
DOIs | |
Publication status | Published - 24 Oct 2018 |
Event | 34th IEEE International Conference on Data Engineering, ICDE 2018 - Paris, France Duration: 16 Apr 2018 → 19 Apr 2018 |
Conference
Conference | 34th IEEE International Conference on Data Engineering, ICDE 2018 |
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Country/Territory | France |
City | Paris |
Period | 16/04/18 → 19/04/18 |
Keywords
- Aggregate sharing
- Aggregation
- out of order
- Scotty
- Session
- Session Windows
- Slicing
- Stream
- Stream Processing
- Stream Slicing
- Window