Data
Parse messy logs
One schema out of several formats, with the lines that do not fit kept.
Fill it in
A sample covering every format.
Stack traces are one event, not forty.
A parser that silently drops 8% looks perfect.
Your prompt
Build a parser for . Sample first and count the formats. There are always more than expected: a service that changed its format mid-window, one that logs JSON except when it crashes, and a proxy that prefixes everything. Handle multiline properly. A stack trace is ONE event, and a parser that emits forty lines produces an error count that is off by an order of magnitude and a search that never finds the cause. Normalise timestamps to UTC with the original zone kept. Mixed local times in one index make every correlation wrong in a way that looks plausible. Route what fails to parse to a dead-letter output and REPORT the rate. A parser that silently drops 8% of lines looks perfect and hides exactly the unusual events you built it to find. Extract a stable schema and say which fields are optional.
Continue and pick your folderOpens with everything above already filled in.
Why this works
A parser that silently drops 8% of lines looks perfect and hides the unusual events you built it to find. This routes failures to a dead letter and reports the rate. It also treats a stack trace as one event rather than forty.