Consistent Main-Memory Database Federations under Deferred Disk Writes

Current cluster architectures provide the ideal environ-ment to run federations of main-memory database sys-tems (FMMDBs). In FMMDBs, data resides in the main memory of the federation servers, significantly improv-ing performance by avoiding I/O during the execution of read operations. To maximize the performance of update transactions as well, some applications recur to deferred disk writes. This means that update transactions com-mit before their modifications are written on stable stor-age and durability must be ensured outside the database. While deferred disk writes in centralized MMDBs relax the durability property of transactions only, in FMMDBs transaction atomicity may be also violated in case of failures. We address this issue from the perspective of log-based rollback-recovery in distributed systems and provide an efficient solution to the problem