OTLP log record with an int64 body is accepted, discarded, and reported as fully successful

Repository: quickwit-oss/quickwit Version: 0.8.2 (quickwit/quickwit:0.8.2), single node, QW_ENABLE_OTLP_ENDPOINT=true Reproduced first-hand: yes, on 2026-09-08.

What happens

A log record whose body is an AnyValue holding int_value is accepted with HTTP 200. The response says rejected_log_records: 0. The record never becomes queryable.

A record identical except for a string_value body, sent seconds later to the same index, is retrievable — so this is specific to the int64 body rather than a slow commit or an unhealthy index.

Reproduction

No tooling beyond curl, base64 and python3 is needed. The payload below is a 123-byte ExportLogsServiceRequest whose single record has body.int_value = 9223372036854775807 and an attribute specmatrix.run set to issue-repro.

docker run -d --name qw -p 7280:7280 \
  -e QW_ENABLE_OTLP_ENDPOINT=true quickwit/quickwit:0.8.2 run

# Quickwit creates otel-logs-v0_7 shortly after /health/livez answers, and the
# write path refuses for about a second after that. Wait before sending.
until curl -sf localhost:7280/health/livez >/dev/null; do sleep 1; done; sleep 10

base64 -d > /tmp/int64.pb <<'B64'
CnkKHgocCgxzZXJ2aWNlLm5hbWUSDAoKc3BlY21hdHJpeBJXCgwKCnNwZWNtYXRyaXgSRwkV9WLc9WTTGBAJGgRJTkZPKgoY//////////9/Mh8KDnNwZWNtYXRyaXgucnVuEg0KC2lzc3VlLXJlcHJvWRX1Ytz1ZNMY
B64

curl -s -X POST localhost:7280/api/v1/otlp/v1/logs \
  -H 'Content-Type: application/x-protobuf' --data-binary @/tmp/int64.pb
sleep 10
curl -s 'localhost:7280/api/v1/otel-logs-v0_7/search?query=attributes.specmatrix.run:issue-repro'

Observed:

{ "partial_success": { "rejected_log_records": 0, "error_message": "" } }
HTTP 200

{ "num_hits": 0, "hits": [], ... }

The same steps with a string_value body return num_hits: 1.

Why this looks like a bug rather than a limitation

LogRecord.body is an AnyValue, and AnyValue may hold int_value; nothing in opentelemetry-proto restricts a body to a string. If Quickwit cannot store an int64 body, OTLP provides the channel for saying so: ExportLogsServiceResponse.partial_success carries rejected_log_records and error_message, and a receiver that drops records is expected to report them there.

The difficulty is not that the record is dropped — it is that the response states that nothing was dropped. A client that reads the response, parses partial_success and checks the count is told the write succeeded completely, so there is no signal available to it at any point.

Would a partial_success count be enough?

From this project's side, yes — a caller could then see the loss and act on it. Storing the value would be better still, but reporting the rejection would move this from silent data loss to a documented limitation.

Where this came from

SpecMatrix, a conformance corpus for observability backends. The check is cases/otlp-logs/body-int64-max.yaml; the rule it cites is the proto3 JSON mapping's encoding of int64 as a decimal string, which exists so that values past 2^53 survive the encoding.

Found by SpecMatrix, a conformance corpus for observability backends. Happy to be told this is configuration or already known — the check will record whichever it turns out to be.