alibaba/spring-ai-alibaba · warning

Fetch attempt failed for URL

Error message

Fetch attempt {} failed for URL: {}: {}

What it means

fetchHtmlWithRetry logs this warning when an individual fetch attempt to the target URL throws a WebFetchException (excluding interrupts) and will retry up to the configured attempt count. The final failure surfaces only after all retries are exhausted.

Solutions

1. Read the cause in the message to identify the underlying network/HTTP problem and fix connectivity (DNS, proxy, firewall).
2. Verify the URL is reachable from the runtime environment (curl it from the same host/container).
3. Increase retry count/backoff in WebFetchTool config for flaky targets.
4. If the target blocks bots, ensure allowed domains and appropriate headers/user agent are configured.

new URL(url); // and curl-check reachability from the runtime host before wiring the tool

try { html = webFetch.fetch(url); } catch (WebFetchException e) { log.error("All retries failed for {}: {}", url, e.getMessage()); return fallbackContent(url); }

When it happens

Trigger: HTTP connection errors, TLS failures, DNS resolution failures, or non-success responses when fetching the given URL, on attempt 'attempt+1' of the retry loop.

Common situations: Fetching an internal/localhost URL from a container without network access, target site rate limiting or blocking the agent's user agent, transient network flaps, invalid TLS certs on intranet hosts.

Understand the failure class

Background: 'Something went wrong' / 'Request failed (500)' / 'HTTP error! status: 404' — what failed HTTP requests actually mean and how to find the real cause — this error's family across 28 libraries.

Related errors

• Failed after attempts
• Failed after attempts:
• failed to create index
• Network error while fetching URL:
• Oauth2CallError

AI-assisted analysis of alibaba/spring-ai-alibaba@f82da0b50f (2026-09-09). Data as JSON: /api/errors/4abf79ad99a85a50. Report an issue: GitHub.

Appendix: source

Thrown at spring-ai-alibaba-agent-framework/src/main/java/com/alibaba/cloud/ai/graph/agent/tools/WebFetchTool.java:260

				HttpResponse<String> response = fetchHtml(url);

				if (response.statusCode() >= 500 && response.statusCode() < 600) {
					lastException = new WebFetchException("Server error: HTTP " + response.statusCode(), null);
					logger.warn("Fetch attempt {} returned server error {} for URL: {}", attempt + 1,
							response.statusCode(), url);
					attempt++;
					continue;
				}

				return response;
			}
			catch (WebFetchException e) {
				lastException = e;
				if (e.getCause() instanceof InterruptedException) {
					throw e;
				}
				logger.warn("Fetch attempt {} failed for URL: {}: {}", attempt + 1, url, e.getMessage());
				attempt++;
			}
			catch (InterruptedException e) {
				Thread.currentThread().interrupt();
				throw new WebFetchException("Retry interrupted", e);
			}
		}

		if (lastException == null) {
			throw new WebFetchException("Failed after " + (this.maxRetries + 1) + " attempts", null);
		}
		else if (lastException instanceof WebFetchException) {
			throw new WebFetchException("Failed after " + (this.maxRetries + 1) + " attempts", lastException);
		}
		else {
			throw new WebFetchException(
					"Failed after " + (this.maxRetries + 1) + " attempts: " + lastException.getMessage(),
					lastException);

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