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.

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);

View on GitHub (pinned to f82da0b50f)

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:
• Oauth2CallError
• failed to create index
• Retry interrupted

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