Plain-Text Log — Multi-Line Events Needing Line Joining (log)
A Spring-style text log where two stack traces span many physical lines. Eight logical events across a larger number of lines, so a shipper's multi-line rule — anything not starting with a timestamp continues the previous event — can be scored against a known answer.
2026-03-17 09:14:32.850 INFO 4211 --- [http-nio-8080-exec-3] c.e.s.c.OrderController : POST /api/checkout started (request_id=req-000411)
2026-03-17 09:14:32.856 DEBUG 4211 --- [http-nio-8080-exec-3] c.e.s.c.PricingService : pricing 3 line items for cart 9f31a7
2026-03-17 09:14:32.998 WARN 4211 --- [http-nio-8080-exec-3] c.e.s.c.PricingService : downstream call took 71ms, budget is 50ms
2026-03-17 09:14:34.921 ERROR 4211 --- [http-nio-8080-exec-3] c.e.s.c.OrderController : Unhandled exception while creating order
java.lang.IllegalStateException: cart 9f31a7 has no priced line items
at com.example.shop.checkout.PricingService.total(PricingService.java:142)
at com.example.shop.checkout.OrderService.place(OrderService.java:88)
at com.example.shop.checkout.OrderController.create(OrderController.java:54)
at java.base/jdk.internal.reflect.DirectMethodHandleAccessor.invoke(DirectMethodHandleAccessor.java:103)
Caused by: java.util.NoSuchElementException: no price row for sku SKU-88213
at com.example.shop.catalog.PriceRepository.require(PriceRepository.java:67)
... 12 more
2026-03-17 09:14:34.930 INFO 4211 --- [http-nio-8080-exec-3] c.e.s.c.OrderController : POST /api/checkout completed status=500 duration=2080ms
2026-03-17 09:14:35.104 INFO 4211 --- [scheduling-1] c.e.s.c.MetricsReporter : flushed 41 metric families
2026-03-17 09:14:36.002 ERROR 4211 --- [http-nio-8080-exec-5] c.e.s.c.OrderController : Unhandled exception while creating order
Traceback (most recent call last):
File "/srv/payments/handlers/authorize.py", line 118, in authorize
charge = psp.create_charge(token, amount_minor, currency)
File "/srv/payments/psp/client.py", line 141, in _post
raise UpstreamTimeout(f"{path} exceeded {timeout}s")
shop.payments.errors.UpstreamTimeout: /v1/charges exceeded 2.0s
2026-03-17 09:14:36.010 INFO 4211 --- [http-nio-8080-exec-5] c.e.s.c.OrderController : POST /api/checkout completed status=500 duration=1904ms
Specifications
- Lines
- 22
- Logical Events
- 8
- Stack Traces
- 2
- Continuation Rule
- a line not starting with a timestamp continues the previous event
- Framework
- Spring-style layout
- Indented Continuations
- true
Testing contract
Expected to pass- Scenario
- Apply a multi-line joining rule and count the resulting events.
- Expected result
- 22 physical lines collapse to exactly 8 logical events, each stack trace staying attached to the ERROR line above it rather than becoming separate events.
What is a .log file?
LOG files are plain-text records of events emitted by software, typically one entry per line with a timestamp, severity, and message. There is no single standard, so formats range from unstructured text to structured JSON lines. They are central to debugging, monitoring, and auditing.
How to use this file
Use an example LOG file to test log parsers, timestamp and severity extraction, line-oriented streaming, and ingestion into monitoring or analysis pipelines.
How to use this file for testing
“Plain-Text Log — Multi-Line Events Needing Line Joining (log)” is a deterministic Novus Examples fixture for Observability, Log parsing, Error handling. Structured and plain-text telemetry with known timestamps, levels, request identifiers, and error states for testing log ingestion, correlation, dashboards, and alert pipelines.
Documented properties for this file: LOG · 1,975 bytes. Compare results against paired or grouped companions on this page when present (clean↔damaged, searchable↔scanned, or format twins) so scores stay reproducible across runs.
Download the file once, keep the path stable in CI or local scripts, and treat the spec table as the contract: dimensions, seeds, field lists, and roles are intentional. Corrupt or invalid samples are labelled as such — expect parsers to fail loudly rather than silently accept them.
Telemetry fixtures use fixed trace IDs, span IDs, and timestamps so ingestion is reproducible run to run. Point your collector, parser, or query layer at the file and assert the documented span tree, metric families, or severity mix; service and host names are invented.
Code examples
grep -i error app-plaintext-multiline.log | head
awk '{print $1, $2, $NF}' app-plaintext-multiline.log | headRelated files
- log.NET Exception with an Inner Exception Chain (log)A .NET exception whose inner exception is introduced by the ---> marker and closed by End of inner exception stack trace, wrapped in pipe-delimited log lines. Error groupers that key on the outermost message alone merge two genuinely different faults here.
- logGo Panic with Full Goroutine Dump (log)A Go panic followed by the runtime's full goroutine dump — four goroutines with their wait states, two-line frames and a created by attribution, separated by blank lines. Blank-line separation defeats multi-line rules that treat an empty line as the end of an event.
- logRust Panic with Numbered Backtrace (log)A Rust panic surrounded by ordinary tracing output: the panic location with line and column, a six-frame numbered backtrace where every frame spans two lines, and the RUST_BACKTRACE note. Frame numbering and the deep indent are what a generic stack parser gets wrong here.
- jsonlStructured Log — Blank, Non-JSON and BOM-Prefixed Lines (jsonl)A JSON Lines file with the debris a real container stream carries: blank and whitespace-only lines, one bare stderr write from a C library, a mid-file byte-order mark and two lines that are valid JSON but not objects. Five real records are in there.
- jsonlStructured Log — Clock Skew Across Three Hosts (jsonl)Three hosts writing to one stream with disagreeing clocks: one 45 seconds behind and one six hours ahead because NTP is unreachable. Interleaved by host, so a naive tail shows events from the future and a retention window silently drops the past.
- jsonlStructured Log — Multi-Line Stack Traces Inside JSON (jsonl)Java, Python and Go stack traces carried inside JSON string fields with their newlines escaped — the shape a structured logger produces, and the one that defeats multi-line joining rules written for plain text. Includes a Caused by chain and a goroutine dump.
Generated by generation/observability.py. Free for any use, no attribution required — license.