Pub Date : 2020-04-01DOI: 10.1109/ICDE48307.2020.00142
Wolfram Wingerath, Felix Gessert, Erik Witt, Hannes Kuhlmann, Florian Bücklers, Benjamin Wollmer, N. Ritter
Users leave when page loads take too long. This simple fact has complex implications for virtually all modern businesses, because accelerating content delivery through caching is not as simple as it used to be. As a fundamental technical challenge, the high degree of personalization in today’s Web has seemingly outgrown the capabilities of traditional content delivery networks (CDNs) which have been designed for distributing static assets under fixed caching times. As an additional legal challenge for services with personalized content, an increasing number of regional data protection laws constrain the ways in which CDNs can be used in the first place. In this paper, we present Speed Kit as a radically different approach for content distribution that combines (1) a polyglot architecture for efficiently caching personalized content with (2) a natively GDPR-compliant client proxy that handles all sensitive information within the user device. We describe the system design and implementation, explain the custom cache coherence protocol to avoid data staleness and achieve Δ-atomicity, and we share field experiences from over a year of productive use in the e-commerce industry.
{"title":"Speed Kit: A Polyglot & GDPR-Compliant Approach For Caching Personalized Content","authors":"Wolfram Wingerath, Felix Gessert, Erik Witt, Hannes Kuhlmann, Florian Bücklers, Benjamin Wollmer, N. Ritter","doi":"10.1109/ICDE48307.2020.00142","DOIUrl":"https://doi.org/10.1109/ICDE48307.2020.00142","url":null,"abstract":"Users leave when page loads take too long. This simple fact has complex implications for virtually all modern businesses, because accelerating content delivery through caching is not as simple as it used to be. As a fundamental technical challenge, the high degree of personalization in today’s Web has seemingly outgrown the capabilities of traditional content delivery networks (CDNs) which have been designed for distributing static assets under fixed caching times. As an additional legal challenge for services with personalized content, an increasing number of regional data protection laws constrain the ways in which CDNs can be used in the first place. In this paper, we present Speed Kit as a radically different approach for content distribution that combines (1) a polyglot architecture for efficiently caching personalized content with (2) a natively GDPR-compliant client proxy that handles all sensitive information within the user device. We describe the system design and implementation, explain the custom cache coherence protocol to avoid data staleness and achieve Δ-atomicity, and we share field experiences from over a year of productive use in the e-commerce industry.","PeriodicalId":6709,"journal":{"name":"2020 IEEE 36th International Conference on Data Engineering (ICDE)","volume":"28 1","pages":"1603-1608"},"PeriodicalIF":0.0,"publicationDate":"2020-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90906910","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-04-01DOI: 10.1109/ICDE48307.2020.00133
Haitao Yuan, Guoliang Li, Ling Feng, Ji Sun, Yue Han
Materializing views is an important method to reduce redundant computations in DBMS, especially for processing large scale analytical queries. However, many existing methods still need DBAs to manually generate materialized views, which are not scalable to a large number of database instances, especially on the cloud database. To address this problem, we propose an automatic view generation method which judiciously selects "highly beneficial" subqueries to generate materialized views. However, there are two challenges. (1) How to estimate the benefit of using a materialized view for a queryƒ (2) How to select optimal subqueries to generate materialized viewsƒ To address the first challenge, we propose a neural network based method to estimate the benefit of using a materialized view to answer a query. In particular, we extract significant features from different perspectives and design effective encoding models to transform these features into hidden representations. To address the second challenge, we model this problem to an ILP (Integer Linear Programming) problem, which aims to maximize the utility by selecting optimal subqueries to materialize. We design an iterative optimization method to select subqueries to materialize. However, this method cannot guarantee the convergence of the solution. To address this issue, we model the iterative optimization process as an MDP (Markov Decision Process) and use the deep reinforcement learning model to solve the problem. Extensive experiments show that our method outperforms existing solutions by 28.4%, 8.8% and 31.7% on three real-world datasets.
{"title":"Automatic View Generation with Deep Learning and Reinforcement Learning","authors":"Haitao Yuan, Guoliang Li, Ling Feng, Ji Sun, Yue Han","doi":"10.1109/ICDE48307.2020.00133","DOIUrl":"https://doi.org/10.1109/ICDE48307.2020.00133","url":null,"abstract":"Materializing views is an important method to reduce redundant computations in DBMS, especially for processing large scale analytical queries. However, many existing methods still need DBAs to manually generate materialized views, which are not scalable to a large number of database instances, especially on the cloud database. To address this problem, we propose an automatic view generation method which judiciously selects \"highly beneficial\" subqueries to generate materialized views. However, there are two challenges. (1) How to estimate the benefit of using a materialized view for a queryƒ (2) How to select optimal subqueries to generate materialized viewsƒ To address the first challenge, we propose a neural network based method to estimate the benefit of using a materialized view to answer a query. In particular, we extract significant features from different perspectives and design effective encoding models to transform these features into hidden representations. To address the second challenge, we model this problem to an ILP (Integer Linear Programming) problem, which aims to maximize the utility by selecting optimal subqueries to materialize. We design an iterative optimization method to select subqueries to materialize. However, this method cannot guarantee the convergence of the solution. To address this issue, we model the iterative optimization process as an MDP (Markov Decision Process) and use the deep reinforcement learning model to solve the problem. Extensive experiments show that our method outperforms existing solutions by 28.4%, 8.8% and 31.7% on three real-world datasets.","PeriodicalId":6709,"journal":{"name":"2020 IEEE 36th International Conference on Data Engineering (ICDE)","volume":"37 1","pages":"1501-1512"},"PeriodicalIF":0.0,"publicationDate":"2020-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"91210970","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-04-01DOI: 10.1109/ICDE48307.2020.00034
Qiang Zhang, Yongkun Li, P. Lee, Yinlong Xu, Qiu Cui, L. Tang
Persistent key-value (KV) stores are mainly designed based on the Log-Structured Merge-tree (LSM-tree), which suffer from large read and write amplifications, especially when KV stores grow in size. Existing design optimizations for LSM-tree-based KV stores often make certain trade-offs and fail to simultaneously improve both the read and write performance on large KV stores without sacrificing scan performance. We design UniKV, which unifies the key design ideas of hash indexing and the LSM-tree in a single system. Specifically, UniKV leverages data locality to differentiate the indexing management of KV pairs. It also develops multiple techniques to tackle the issues caused by unifying the indexing techniques, so as to simultaneously improve the performance in reads, writes, and scans. Experiments show that UniKV significantly outperforms several state-of-the-art KV stores (e.g., LevelDB, RocksDB, HyperLevelDB, and PebblesDB) in overall throughput under read-write mixed workloads.
{"title":"UniKV: Toward High-Performance and Scalable KV Storage in Mixed Workloads via Unified Indexing","authors":"Qiang Zhang, Yongkun Li, P. Lee, Yinlong Xu, Qiu Cui, L. Tang","doi":"10.1109/ICDE48307.2020.00034","DOIUrl":"https://doi.org/10.1109/ICDE48307.2020.00034","url":null,"abstract":"Persistent key-value (KV) stores are mainly designed based on the Log-Structured Merge-tree (LSM-tree), which suffer from large read and write amplifications, especially when KV stores grow in size. Existing design optimizations for LSM-tree-based KV stores often make certain trade-offs and fail to simultaneously improve both the read and write performance on large KV stores without sacrificing scan performance. We design UniKV, which unifies the key design ideas of hash indexing and the LSM-tree in a single system. Specifically, UniKV leverages data locality to differentiate the indexing management of KV pairs. It also develops multiple techniques to tackle the issues caused by unifying the indexing techniques, so as to simultaneously improve the performance in reads, writes, and scans. Experiments show that UniKV significantly outperforms several state-of-the-art KV stores (e.g., LevelDB, RocksDB, HyperLevelDB, and PebblesDB) in overall throughput under read-write mixed workloads.","PeriodicalId":6709,"journal":{"name":"2020 IEEE 36th International Conference on Data Engineering (ICDE)","volume":"14 1","pages":"313-324"},"PeriodicalIF":0.0,"publicationDate":"2020-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88573062","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-04-01DOI: 10.1109/ICDE48307.2020.00090
Wangze Ni, Peng Cheng, Lei Chen, Xuemin Lin
Ubiquitous smart devices and high-quality wireless networks enable people to participate in spatial crowdsourcing tasks easily, which require workers to physically move to specific locations to conduct their assigned tasks. Spatial crowdsourcing has attracted much attention from both academia and industry. In this paper, we consider a spatial crowdsourcing scenario, where the tasks may have some dependencies among them. Specifically, one task can only be dispatched when its dependent tasks have already been assigned. In fact, task dependencies are quite common in many real-life applications, such as house repairing and holding sports games. We formally define the dependency-aware spatial crowdsourcing (DA-SC), which focuses on finding an optimal worker-and-task assignment under the constraints of dependencies, skills of workers, moving distances and deadlines to maximize the successfully assigned tasks. We prove that the DA-SC problem is NP-hard and thus intractable. Therefore, we propose two approximation algorithms, including a greedy approach and a game-theoretic approach, which can guarantee the approximate bounds of the results in each batch process. Through extensive experiments on both real and synthetic data sets, we demonstrate the efficiency and effectiveness of our DA-SC approaches.
{"title":"Task Allocation in Dependency-aware Spatial Crowdsourcing","authors":"Wangze Ni, Peng Cheng, Lei Chen, Xuemin Lin","doi":"10.1109/ICDE48307.2020.00090","DOIUrl":"https://doi.org/10.1109/ICDE48307.2020.00090","url":null,"abstract":"Ubiquitous smart devices and high-quality wireless networks enable people to participate in spatial crowdsourcing tasks easily, which require workers to physically move to specific locations to conduct their assigned tasks. Spatial crowdsourcing has attracted much attention from both academia and industry. In this paper, we consider a spatial crowdsourcing scenario, where the tasks may have some dependencies among them. Specifically, one task can only be dispatched when its dependent tasks have already been assigned. In fact, task dependencies are quite common in many real-life applications, such as house repairing and holding sports games. We formally define the dependency-aware spatial crowdsourcing (DA-SC), which focuses on finding an optimal worker-and-task assignment under the constraints of dependencies, skills of workers, moving distances and deadlines to maximize the successfully assigned tasks. We prove that the DA-SC problem is NP-hard and thus intractable. Therefore, we propose two approximation algorithms, including a greedy approach and a game-theoretic approach, which can guarantee the approximate bounds of the results in each batch process. Through extensive experiments on both real and synthetic data sets, we demonstrate the efficiency and effectiveness of our DA-SC approaches.","PeriodicalId":6709,"journal":{"name":"2020 IEEE 36th International Conference on Data Engineering (ICDE)","volume":"61 1","pages":"985-996"},"PeriodicalIF":0.0,"publicationDate":"2020-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90996187","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-04-01DOI: 10.1109/ICDE48307.2020.00096
Yan Li, Tingjian Ge, Cindy X. Chen
Knowledge graphs have seen increasingly broad applications. However, they are known to be incomplete. We define the notion of a virtual knowledge graph which extends a knowledge graph with predicted edges and their probabilities. We focus on two important types of queries: top-k entity queries and aggregate queries. To improve query processing efficiency, we propose an incremental index on top of low dimensional entity vectors transformed from network embedding vectors. We also devise query processing algorithms with the index. Moreover, we provide theoretical guarantees of accuracy, and conduct a systematic experimental evaluation. The experiments show that our approach is very efficient and effective. In particular, with the same or better accuracy guarantees, it is one to two orders of magnitude faster in query processing than the closest previous work which can only handle one relationship type.
{"title":"Online Indices for Predictive Top-k Entity and Aggregate Queries on Knowledge Graphs","authors":"Yan Li, Tingjian Ge, Cindy X. Chen","doi":"10.1109/ICDE48307.2020.00096","DOIUrl":"https://doi.org/10.1109/ICDE48307.2020.00096","url":null,"abstract":"Knowledge graphs have seen increasingly broad applications. However, they are known to be incomplete. We define the notion of a virtual knowledge graph which extends a knowledge graph with predicted edges and their probabilities. We focus on two important types of queries: top-k entity queries and aggregate queries. To improve query processing efficiency, we propose an incremental index on top of low dimensional entity vectors transformed from network embedding vectors. We also devise query processing algorithms with the index. Moreover, we provide theoretical guarantees of accuracy, and conduct a systematic experimental evaluation. The experiments show that our approach is very efficient and effective. In particular, with the same or better accuracy guarantees, it is one to two orders of magnitude faster in query processing than the closest previous work which can only handle one relationship type.","PeriodicalId":6709,"journal":{"name":"2020 IEEE 36th International Conference on Data Engineering (ICDE)","volume":"20 1","pages":"1057-1068"},"PeriodicalIF":0.0,"publicationDate":"2020-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89430975","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-04-01DOI: 10.1109/ICDE48307.2020.00209
Shufeng Gong, Yanfeng Zhang, Ge Yu
Existing graph partition methods are designed for round-robin synchronous distributed frameworks. They balance workload without discrimination of vertex importance and fail to consider the characteristics of priority-based scheduling, which may limit the benefit of prioritized graph computation. To accelerate prioritized iterative graph computations, we propose Hotness Balanced Partition (HBP) and a stream-based partition algorithm Pb-HBP. Pb-HBP partitions graph by distributing vertices with discrimination according to their hotness rather than blindly distributing vertices with equal weights, which aims to evenly distribute the hot vertices among workers. Our results show that our proposed partition method outperforms the state-of-the-art partition methods, Fennel and HotGraph. Specifically, Pb-HBP can reduce 40–90% runtime of that by hash partition, 5–75% runtime of that by Fennel, and 22–50% runtime of that by HotGraph.
{"title":"HBP: Hotness Balanced Partition for Prioritized Iterative Graph Computations","authors":"Shufeng Gong, Yanfeng Zhang, Ge Yu","doi":"10.1109/ICDE48307.2020.00209","DOIUrl":"https://doi.org/10.1109/ICDE48307.2020.00209","url":null,"abstract":"Existing graph partition methods are designed for round-robin synchronous distributed frameworks. They balance workload without discrimination of vertex importance and fail to consider the characteristics of priority-based scheduling, which may limit the benefit of prioritized graph computation. To accelerate prioritized iterative graph computations, we propose Hotness Balanced Partition (HBP) and a stream-based partition algorithm Pb-HBP. Pb-HBP partitions graph by distributing vertices with discrimination according to their hotness rather than blindly distributing vertices with equal weights, which aims to evenly distribute the hot vertices among workers. Our results show that our proposed partition method outperforms the state-of-the-art partition methods, Fennel and HotGraph. Specifically, Pb-HBP can reduce 40–90% runtime of that by hash partition, 5–75% runtime of that by Fennel, and 22–50% runtime of that by HotGraph.","PeriodicalId":6709,"journal":{"name":"2020 IEEE 36th International Conference on Data Engineering (ICDE)","volume":"13 1","pages":"1942-1945"},"PeriodicalIF":0.0,"publicationDate":"2020-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86640639","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-04-01DOI: 10.1109/ICDE48307.2020.00104
Dong Wen, Yilun Huang, Ying Zhang, Lu Qin, W. Zhang, Xuemin Lin
Reachability is a fundamental problem in graph analysis. In applications such as social networks and collaboration networks, edges are always associated with timestamps. Most existing works on reachability queries in temporal graphs assume that two vertices are related if they are connected by a path with non-decreasing timestamps (time-respecting) of edges. This assumption fails to capture the relationship between entities involved in the same group or activity with no time-respecting path connecting them. In this paper, we define a new reachability model, called span-reachability, designed to relax the time order dependency and identify the relationship between entities in a given time period. We adopt the idea of two-hop cover and propose an index-based method to answer span-reachability queries. Several optimizations are also given to improve the efficiency of index construction and query processing. We conduct extensive experiments on 17 real-world datasets to show the efficiency of our proposed solution.
{"title":"Efficiently Answering Span-Reachability Queries in Large Temporal Graphs","authors":"Dong Wen, Yilun Huang, Ying Zhang, Lu Qin, W. Zhang, Xuemin Lin","doi":"10.1109/ICDE48307.2020.00104","DOIUrl":"https://doi.org/10.1109/ICDE48307.2020.00104","url":null,"abstract":"Reachability is a fundamental problem in graph analysis. In applications such as social networks and collaboration networks, edges are always associated with timestamps. Most existing works on reachability queries in temporal graphs assume that two vertices are related if they are connected by a path with non-decreasing timestamps (time-respecting) of edges. This assumption fails to capture the relationship between entities involved in the same group or activity with no time-respecting path connecting them. In this paper, we define a new reachability model, called span-reachability, designed to relax the time order dependency and identify the relationship between entities in a given time period. We adopt the idea of two-hop cover and propose an index-based method to answer span-reachability queries. Several optimizations are also given to improve the efficiency of index construction and query processing. We conduct extensive experiments on 17 real-world datasets to show the efficiency of our proposed solution.","PeriodicalId":6709,"journal":{"name":"2020 IEEE 36th International Conference on Data Engineering (ICDE)","volume":"109 1","pages":"1153-1164"},"PeriodicalIF":0.0,"publicationDate":"2020-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87325816","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-04-01DOI: 10.1109/ICDE48307.2020.00056
Zhongle Xie, Hongbin Ying, Cong Yue, Meihui Zhang, Gang Chen, B. Ooi
With a huge volume and variety of data accumulated over the years, OnLine Analytical Processing (OLAP) systems are facing challenges in query efficiency. Furthermore, the design of OLAP systems cannot serve modern applications well due to their inefficiency in processing complex queries such as cohort queries with low query latency. In this paper, we present Cool, a cohort online analytical processing system. As an integrated system with the support of several newly proposed operators on top of a sophisticated storage layer, it processes both cohort queries and conventional OLAP queries with superb performance. Its distributed design contains minimal load balancing and fault tolerance support and is scalable. Our evaluation results show that Cool outperforms two state-of-the-art systems, MonetDB and Druid, by a wide margin in single-node setting. The multi-node version of Cool can also beat the distributed Druid, as well as SparkSQL, by one order of magnitude in terms of query latency.
{"title":"Cool, a COhort OnLine analytical processing system","authors":"Zhongle Xie, Hongbin Ying, Cong Yue, Meihui Zhang, Gang Chen, B. Ooi","doi":"10.1109/ICDE48307.2020.00056","DOIUrl":"https://doi.org/10.1109/ICDE48307.2020.00056","url":null,"abstract":"With a huge volume and variety of data accumulated over the years, OnLine Analytical Processing (OLAP) systems are facing challenges in query efficiency. Furthermore, the design of OLAP systems cannot serve modern applications well due to their inefficiency in processing complex queries such as cohort queries with low query latency. In this paper, we present Cool, a cohort online analytical processing system. As an integrated system with the support of several newly proposed operators on top of a sophisticated storage layer, it processes both cohort queries and conventional OLAP queries with superb performance. Its distributed design contains minimal load balancing and fault tolerance support and is scalable. Our evaluation results show that Cool outperforms two state-of-the-art systems, MonetDB and Druid, by a wide margin in single-node setting. The multi-node version of Cool can also beat the distributed Druid, as well as SparkSQL, by one order of magnitude in terms of query latency.","PeriodicalId":6709,"journal":{"name":"2020 IEEE 36th International Conference on Data Engineering (ICDE)","volume":"1 1","pages":"577-588"},"PeriodicalIF":0.0,"publicationDate":"2020-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85476654","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-04-01DOI: 10.1109/ICDE48307.2020.00207
Chenhao Huang, Michael J. Cahill, A. Fekete, Uwe Röhm
MongoDB is a popular document store that is also available as a cloud-hosted service. MongoDB internally deploys primary-copy asynchronous replication, and it allows clients to vary the Read Preference, so reads can deliberately be directed to secondaries rather than the primary site. Doing this can sometimes improve performance, but the returned data might be stale, whereas the primary always returns the freshest data value. While state-of-practice is for programmers to decide where to direct the reads at application development time, they do not have full understanding then of workload or hardware capacity. It should be better to choose the appropriate Read Preference setting at runtime, as we describe in this paper.We show how a system can detect when the primary copy is saturated in MongoDB-as-a-Service, and use this to choose where reads should be done to improve overall performance. Our approach is aimed at a cloud-consumer; it assumes access to only the limited diagnostic data provided to clients of the hosted service.
{"title":"Deciding When to Trade Data Freshness for Performance in MongoDB-as-a-Service","authors":"Chenhao Huang, Michael J. Cahill, A. Fekete, Uwe Röhm","doi":"10.1109/ICDE48307.2020.00207","DOIUrl":"https://doi.org/10.1109/ICDE48307.2020.00207","url":null,"abstract":"MongoDB is a popular document store that is also available as a cloud-hosted service. MongoDB internally deploys primary-copy asynchronous replication, and it allows clients to vary the Read Preference, so reads can deliberately be directed to secondaries rather than the primary site. Doing this can sometimes improve performance, but the returned data might be stale, whereas the primary always returns the freshest data value. While state-of-practice is for programmers to decide where to direct the reads at application development time, they do not have full understanding then of workload or hardware capacity. It should be better to choose the appropriate Read Preference setting at runtime, as we describe in this paper.We show how a system can detect when the primary copy is saturated in MongoDB-as-a-Service, and use this to choose where reads should be done to improve overall performance. Our approach is aimed at a cloud-consumer; it assumes access to only the limited diagnostic data provided to clients of the hosted service.","PeriodicalId":6709,"journal":{"name":"2020 IEEE 36th International Conference on Data Engineering (ICDE)","volume":"53 1","pages":"1934-1937"},"PeriodicalIF":0.0,"publicationDate":"2020-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85713594","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-04-01DOI: 10.1109/ICDE48307.2020.00177
Chengliang Chai, Guoliang Li, Ju Fan, Yuyu Luo
Visualization charts are widely utilized for presenting structured data. Under many circumstances, people want to explore the data in the charts collected from various sources, such as papers and websites, so as to further analyzing the data or creating new charts. However, the existing automatic and semi-automatic approaches are not always effective due to the variety of charts. In this paper, we introduce a crowdsourcing approach that leverages human ability to extract data from visualization charts. There are several challenges. The first one is how to avoid tedious human interaction with charts and design simple crowdsourcing tasks. Second, it is challenging to evaluate worker’s quality for truth inference, because workers may not only provide inaccurate values but also misalign values to wrong data series. To address the challenges, we design an effective crowdsourcing task scheme that splits a chart into simple micro-tasks. We introduce a novel worker quality model by considering worker’s accuracy and task difficulty. We also devise an effective early-stopping mechanisms to save the cost. We have conducted experiments on a real crowdsourcing platform, and the results show that our framework outperforms state-of-the-art approaches on both cost and quality.
{"title":"Crowdsourcing-based Data Extraction from Visualization Charts","authors":"Chengliang Chai, Guoliang Li, Ju Fan, Yuyu Luo","doi":"10.1109/ICDE48307.2020.00177","DOIUrl":"https://doi.org/10.1109/ICDE48307.2020.00177","url":null,"abstract":"Visualization charts are widely utilized for presenting structured data. Under many circumstances, people want to explore the data in the charts collected from various sources, such as papers and websites, so as to further analyzing the data or creating new charts. However, the existing automatic and semi-automatic approaches are not always effective due to the variety of charts. In this paper, we introduce a crowdsourcing approach that leverages human ability to extract data from visualization charts. There are several challenges. The first one is how to avoid tedious human interaction with charts and design simple crowdsourcing tasks. Second, it is challenging to evaluate worker’s quality for truth inference, because workers may not only provide inaccurate values but also misalign values to wrong data series. To address the challenges, we design an effective crowdsourcing task scheme that splits a chart into simple micro-tasks. We introduce a novel worker quality model by considering worker’s accuracy and task difficulty. We also devise an effective early-stopping mechanisms to save the cost. We have conducted experiments on a real crowdsourcing platform, and the results show that our framework outperforms state-of-the-art approaches on both cost and quality.","PeriodicalId":6709,"journal":{"name":"2020 IEEE 36th International Conference on Data Engineering (ICDE)","volume":"1 1","pages":"1814-1817"},"PeriodicalIF":0.0,"publicationDate":"2020-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82983461","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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