languagetool-org/languagetool · warning · TooManyRequestsException

IP request size limit of bytes per seconds exceeded in…

Error message

IP request size limit of  bytes per  seconds exceeded in text-level checks

What it means

RequestLimiter enforces a per-IP request-size quota in Mode.TEXTLEVEL_ONLY. When the total bytes of requests from one IP address exceed ipRequestLimitInBytes within requestLimitPeriodInSeconds, checkLimit throws TooManyRequestsException (HTTP 429). This limits aggregate bandwidth per client IP regardless of fingerprint.

Solutions

1. Wait for requestLimitPeriodInSeconds to pass, then resume with reduced volume
2. Add client-side throttling/backoff: track bytes sent and cap below ipRequestLimitInBytes per window
3. Use an authenticated Premium account with higher per-IP limits
4. If you administer the server, raise the IP size limit (ipRequestLimitInBytes) in HTTPServerConfig/launch options
5. Move the workload to a different IP or distribute requests across allowed clients

Example fix

// before: unbounded loop
for (doc : docs) client.check(doc, Mode.TEXTLEVEL_ONLY);
// after: rate-aware loop
long sent = 0; long windowStart = now();
for (doc : docs) {
  if (now()-windowStart > period) { sent = 0; windowStart = now(); }
  if (sent + doc.length() > ipLimitBytes) sleep(windowStart + period - now());
  client.check(doc, Mode.TEXTLEVEL_ONLY); sent += doc.length();
}

function canSend(bytes) { return bytesSentFromThisIpInWindow + bytes <= IP_LIMIT_BYTES; }

try {
  const res = await api.check(text);
} catch (e) {
  if (e.response && e.response.status === 429) { await sleep(periodMs); return api.check(text); }
  throw e;
}

When it happens

Trigger: POSTing to /v2/check with mode=textLevelOnly where cumulative request bytes from the client IP exceed ipRequestLimitInBytes within requestLimitPeriodInSeconds (and requestLimitInBytes > 0).

Common situations: Automated scripts or CI jobs behind one IP sending many large requests; multiple users behind a NAT/proxy sharing the quota; server configured with a tight IP size limit (ipRequestLimitInBytes); rapid retry loops amplifying usage.

Related errors

• Client request size limit of bytes per seconds exceeded…
• Client request size limit of bytes per seconds exceeded
• IP request size limit of bytes per seconds exceeded
• Client request limit of requests per seconds exceeded
• IP request limit of requests per seconds exceeded

AI-assisted analysis of languagetool-org/languagetool@2e990059ce (2026-09-06). Data as JSON: /api/errors/6cc5098e2efeec57. Report an issue: GitHub.

Appendix: source

Thrown at languagetool-server/src/main/java/org/languagetool/server/RequestLimiter.java:234

        }
        if (ipFingerprintFactor > 0 && requestLimit > 0 && requestsByFingerprint > requestLimit) {
          String msg = "limit: " + requestLimit + " / " + requestLimitPeriodInSeconds + ", requests: "  + requestsByIp + ", ip: " + ipAddress + ", fingerprint: " + fingerprint;
          throw new TooManyRequestsException("Client request limit of " + requestLimit + " requests per " +
            requestLimitPeriodInSeconds + " seconds exceeded"); }
        if (requestLimit > 0 && requestsByIp > ipRequestLimit) {
          String msg = "limit: " + ipRequestLimit + " / " + requestLimitPeriodInSeconds + ", requests: "  + requestsByIp + ", ip: " + ipAddress + ", fingerprint: " + fingerprint;
          throw new TooManyRequestsException("IP request limit of " + ipRequestLimit + " requests per " +
            requestLimitPeriodInSeconds + " seconds exceeded");
        }
        if (event.mode == JLanguageTool.Mode.TEXTLEVEL_ONLY) {
          if (ipFingerprintFactor > 0 && requestLimitInBytes > 0 && requestSizeByFingerprint > requestLimitInBytes) {
            String msg = "limit in Mode.TEXTLEVEL_ONLY: " + requestLimitInBytes + " / " + requestLimitPeriodInSeconds + ", request size: "  + requestSizeByIp + ", ip: " + ipAddress + ", fingerprint: " + fingerprint;
            throw new TooManyRequestsException("Client request size limit of " + requestLimitInBytes + " bytes per " +
              requestLimitPeriodInSeconds + " seconds exceeded in text-level checks");
          }
          if (requestLimitInBytes > 0 && requestSizeByIp > ipRequestLimitInBytes) {
            String msg = "limit in Mode.TEXTLEVEL_ONLY: " + ipRequestLimitInBytes + " / " + requestLimitPeriodInSeconds + ", request size: "  + requestSizeByIp + ", ip: " + ipAddress + ", fingerprint: " + fingerprint;
            throw new TooManyRequestsException("IP request size limit of " + ipRequestLimitInBytes + " bytes per " +
              requestLimitPeriodInSeconds + " seconds exceeded in text-level checks");
          }
        } else {
          if (ipFingerprintFactor > 0 && requestLimitInBytes > 0 && requestSizeByFingerprint > requestLimitInBytes) {
            String msg = "limit: " + requestLimitInBytes + " / " + requestLimitPeriodInSeconds + ", request size: "  + requestSizeByIp + ", ip: " + ipAddress + ", fingerprint: " + fingerprint;
            throw new TooManyRequestsException("Client request size limit of " + requestLimitInBytes + " bytes per " +
              requestLimitPeriodInSeconds + " seconds exceeded");
          }
          if (requestLimitInBytes > 0 && requestSizeByIp > ipRequestLimitInBytes) {
            String msg = "limit: " + ipRequestLimitInBytes + " / " + requestLimitPeriodInSeconds + ", request size: "  + requestSizeByIp + ", ip: " + ipAddress + ", fingerprint: " + fingerprint;
            throw new TooManyRequestsException("IP request size limit of " + ipRequestLimitInBytes + " bytes per " +
              requestLimitPeriodInSeconds + " seconds exceeded");
          }
        }
      }
    }
  }
  

View on GitHub (pinned to 2e990059ce)