thanos-io/thanos · error

read compressed request body

Error message

read compressed request body

What it means

io.Copy from r.Body into the compressed buffer failed while reading the snappy-compressed request body (client disconnect or network error mid-upload), so the handler responds 500 and the request is lost.

Solutions

1. Retry the request; the connection broke mid-transfer.
2. Check client and network stability.
3. Verify no proxy times out long uploads.

When it happens

Trigger: Thrown at pkg/receive/handler.go:829 when the library encounters an invalid state.

Common situations: See trigger scenarios.

AI-assisted analysis of thanos-io/thanos@35b8b99117 (2026-09-07). Data as JSON: /api/errors/6cc64973c882d2da. Report an issue: GitHub.

Appendix: source

Thrown at pkg/receive/handler.go:829

		return
	}

	requestLimiter := h.Limiter.RequestLimiter()
	// io.ReadAll dynamically adjust the byte slice for read data, starting from 512B.
	// Since this is receive hot path, grow upfront saving allocations and CPU time.
	compressed := bytes.Buffer{}
	if r.ContentLength >= 0 {
		if !requestLimiter.AllowSizeBytes(tenantHTTP, r.ContentLength) {
			http.Error(w, "write request too large", http.StatusRequestEntityTooLarge)
			return
		}
		compressed.Grow(int(r.ContentLength))
	} else {
		compressed.Grow(512)
	}
	_, err = io.Copy(&compressed, r.Body)
	if err != nil {
		http.Error(w, errors.Wrap(err, "read compressed request body").Error(), http.StatusInternalServerError)
		return
	}
	reqBuf, err := s2.Decode(nil, compressed.Bytes())
	if err != nil {
		level.Error(tLogger).Log("msg", "snappy decode error", "err", err)
		http.Error(w, errors.Wrap(err, "snappy decode error").Error(), http.StatusBadRequest)
		return
	}

	if !requestLimiter.AllowSizeBytes(tenantHTTP, int64(len(reqBuf))) {
		http.Error(w, "write request too large", http.StatusRequestEntityTooLarge)
		return
	}

	rwVersion, err := determineRWVersion(r)
	if err != nil {
		http.Error(w, err.Error(), http.StatusBadRequest)
		return

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