ABSTRACT
In this paper, we propose a new location-aware pub/sub system, Elaps, that continuously monitors moving users subscribing to dynamic event streams from social media and E-commerce applications. Users are notified instantly when there is a matching event nearby. To the best of our knowledge, Elaps is the first to take into account continuous moving queries against dynamic event streams. Like existing works on continuous moving query processing,Elaps employs the concept of safe region to reduce communication overhead. However, unlike existing works which assume data from publishers are static, updates to safe regions may be triggered by newly arrived events. In Elaps, we develop a concept called \textit{impact region} that allows us to identify whether a safe region is affected by newly arrived events. Moreover, we propose a novel cost model to optimize the safe region size to keep the communication overhead low. Based on the cost model, we design two incremental methods, iGM and idGM, for safe region construction. In addition, Elaps uses boolean expression, which is more expressive than keywords, to model user intent and we propose a novel index, BEQ-Tree, to handle spatial boolean expression matching. In our experiments, we use geo-tweets from Twitter and venues from Foursquare to simulate publishers and boolean expressions generated from AOL search log to represent users intentions. We test user movement in both synthetic trajectories and real taxi trajectories. The results show that Elaps can significantly reduce the communication overhead and disseminate events to users in real-time.
- J. Bao, M. Mokbel, and C.-Y. Chow, "Geofeed: A location aware news feed system," in ICDE, 2012, pp. 54--65. Google ScholarDigital Library
- G. Li, Y. Wang, T. Wang, and J. Feng, "Location-aware publish/subscribe," in KDD, 2013, pp. 802--810. Google ScholarDigital Library
- L. Chen, G. Cong, and X. Cao, "An efficient query indexing mechanism for filtering geo-textual data," in SIGMOD, 2013, pp. 749--760. Google ScholarDigital Library
- G. Cugola and A. Margara, "High-performance location-aware publish-subscribe on gpus," in Middleware, 2012, pp. 312--331. Google ScholarDigital Library
- J. Zhang, M. Zhu, D. Papadias, Y. Tao, and D. L. Lee, "Location-based spatial queries," in SIGMOD, 2003, pp. 443--454. Google ScholarDigital Library
- M. Hasan, M. A. Cheema, X. Lin, and Y. Zhang, "Efficient construction of safe regions for moving knn queries over dynamic datasets," in phSSTD, 2009, pp. 373--379. Google ScholarDigital Library
- B. Bamba, L. Liu, A. Iyengar, and P. S. Yu, "Safe region techniques for fast spatial alarm evaluation," Georgia Institute of Technology, 2008.Google Scholar
- D. Wu, M. L. Yiu, C. S. Jensen, and G. Cong, "Efficient continuously moving top-k spatial keyword query processing," in ICDE, 2011, pp. 541--552. Google ScholarDigital Library
- W. Huang, G. Li, K.-L. Tan, and J. Feng, "Efficient safe-region construction for moving top-k spatial keyword queries," in CIKM, 2012, pp. 932--941. Google ScholarDigital Library
- L. Guo, J. Shao, H. Aung, and K.-L. Tan, "Efficient continuous top-k spatial keyword queries on road networks," Geo Informatica, pp. 1--32, 2014. Google ScholarDigital Library
- R. Finkel and J. Bentley, "Quad trees a data structure for retrieval on composite keys," Acta Informatica, vol. 4, no. 1, pp. 1--9, 1974. Google ScholarDigital Library
- W. Xu, C.-Y. Chow, M. L. Yiu, Q. Li, and C. K. Poon, "Mobifeed: A location-aware news feed system for mobile users," in SIGSPATIAL '12, 2012, pp. 538--541. Google ScholarDigital Library
- F. Fabret, H. A. Jacobsen, F. Llirbat, J. Pereira, K. A. Ross, and D. Shasha, "Filtering algorithms and implementation for very fast publish/subscribe systems," in SIGMOD, 2001, pp. 115--126. Google ScholarDigital Library
- S. E. Whang, H. Garcia-Molina, C. Brower, J. Shanmugasundaram, S. Vassilvitskii, E. Vee, and R. Yerneni, "Indexing boolean expressions," PVLDB, vol. 2, no. 1, pp. 37--48, 2009. Google ScholarDigital Library
- M. Sadoghi and H.-A. Jacobsen, "Be-tree: An index structure to efficiently match boolean expressions over high-dimensional discrete space," in SIGMOD, 2011, pp. 637--648. Google ScholarDigital Library
- D. Zhang, C.-Y. Chan, and K.-L. Tan, "An efficient publish/subscribe index for ecommerce databases," PVLDB, vol. 7, no. 8, pp. 613--624, 2014. Google ScholarDigital Library
- H. V. Jagadish, B. C. Ooi, K.-L. Tan, C. Yu, and R. Zhang, "idistance: An adaptive b-tree based indexing method for nearest neighbor search," TODS, vol. 30, no. 2, pp. 364--397, 2005. Google ScholarDigital Library
- T. W. Yan and H. García-Molina, "Index structures for selective dissemination of information under the boolean model," TODS, vol. 19, no. 2, pp. 332--364, 1994. Google ScholarDigital Library
- A. Guttman, "R-trees: A dynamic index structure for spatial searching," in SIGMOD, 1984, pp. 47--57. Google ScholarDigital Library
- T. Brinkhoff, "A framework for generating network-based moving objects," Geoinformatica, vol. 6, no. 2, pp. 153--180, 2002. Google ScholarDigital Library
- J. Zhou, A. K. Tung, W. Wu, and W. S. Ng, "A 'semi-lazy' approach to probabilistic path prediction in dynamic environments," in KDD '13, 2013, pp. 748--756. Google ScholarDigital Library
- G. Antoshenkov and M. Ziauddin, "Query processing and optimization in oracle rdb," The VLDB Journal, vol. 5, no. 4, pp. 229--237, 1996. Google ScholarDigital Library
- K. Wu, E. J. Otoo, and A. Shoshani, "Optimizing bitmap indices with efficient compression," ACM Trans. Database Syst., vol. 31, no. 1, pp. 1--38, Mar. 2006. Google ScholarDigital Library
- F. Ramsak, V. Markl, R. Fenk, M. Zirkel, K. Elhardt, and R. Bayer, "Integrating the ub-tree into a database system kernel," in VLDB '00, 2000, pp. 263--272. Google ScholarDigital Library
Index Terms
- Location-Aware Pub/Sub System: When Continuous Moving Queries Meet Dynamic Event Streams
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