Preference-Aware Query and Update Scheduling in Web-databases

Typical web-database systems receive read-only queries, that generate dynamic web pages as a response, and writeonly updates, that keep information up-to-date. Users expect short response times and low staleness. However, it may be extremely hard to apply all updates on time, i.e., keep zero staleness, and also get fast response times, especially in periods of bursty traffic. In this paper, we present the concept of Quality Contracts (QCs) which combines the two incomparable performance metrics: response time or Quality of Service (QoS), and staleness or Quality of Data (QoD). QCs allows individual users to express their preferences for the expected QoS and QoD of their queries by assigning "profit" values. To maximize the total profit from submitted QCs, we propose an adaptive algorithm, called QUTS. QUTS addresses the problem of prioritizing the scheduling of updates over queries using a twolevel scheduling scheme that dynamically allocates CPU resources to updates and que...

• Type: Conference
• Year: 2007
• Where: ICDE
• Authors: Huiming Qu, Alexandros Labrinidis
• Keywords: Database, Fast Response Times, ICDE 2007, Read-only Queries, Submitted Qcs