The fsync interval
write said the record was saved. The power cut a moment later. Is it on disk, and what did confirming it cost?
A program appends small records to a file. Each write lands in memory and returns at once; the disk gets them only when the program asks for an fsync. Choose how often to ask, then cut the power. The panels show records written a second, records the crash took, and which ones had reached the disk.
Board: IO Interrupts and the Bus →On a narrow screen the three panels stack below the tabs and crash slider. The table scrolls sideways.
try this Click After every record, then Every 1,000 records, drag Where the power cuts, and watch Lost on the crash.
Included with a plan
This lab is included with a plan. The first three lessons of every track are free, with their boards and videos. A plan unlocks every lesson, board, video, lab and paper for one price.
see also ARIES: A Transaction Recovery Method Supporting Fine-Granularity Locking and Partial Rollbacks Using Write-Ahead Logging in Papers.