Aether: A Scalable Approach to Logging

The shift to multi-core hardware brings new challenges to database systems, as the software parallelism determines performance. Even though database systems traditionally accommodate simultaneous requests, a multitude of synchronization barriers serialize execution. Write-ahead logging is a fundamental, omnipresent component in ARIES-style concurrency and recovery, and one of the most important yet-to-be addressed potential bottlenecks, especially in OLTP workloads making frequent small changes to data. In this paper, we identify four logging-related impediments to database system scalability. Each issue challenges different level in the software architecture: (a) the high volume of small-sized I/O requests may saturate the disk, (b) transactions hold locks while waiting for the log flush, (c) extensive context switching overwhelms the OS scheduler with threads executing log I/Os, and (d) contention appears as transactions serialize accesses to in-memory log data structures. We demons...

• Type: Journal
• Year: 2010
• Where: PVLDB
• Authors: Ryan Johnson, Ippokratis Pandis, Radu Stoica, Manos Athanassoulis, Anastasia Ailamaki
• Keywords: Database System, Frequent Small Changes, In-memory Log Data, PVLDB 2010