alibaba/spring-ai-alibaba · warning

Command timed out, restarting session

Error message

Command timed out, restarting session

What it means

collectOutput waited until the command deadline expired without the shell producing a final output line; it logs this warning, calls restart() to recreate the session, and returns with a timeout indication. The command is not allowed to run past the configured timeout.

Source

Thrown at spring-ai-alibaba-agent-framework/src/main/java/com/alibaba/cloud/ai/graph/agent/tools/ShellSessionManager.java:529

			} catch (IOException e) {
				throw new RuntimeException("Failed to execute command", e);
			}
		}

		private CommandResult collectOutput(String marker, long deadline, int maxOutputLines, Long maxOutputBytes) {
			List<String> lines = new ArrayList<>();
			int totalLines = 0;
			long totalBytes = 0;
			boolean truncatedByLines = false;
			boolean truncatedByBytes = false;
			Integer exitCode = null;
			boolean timedOut = false;

			while (true) {
				long remaining = deadline - System.currentTimeMillis();
				if (remaining <= 0) {
					timedOut = true;
					log.warn("Command timed out, restarting session");
					restart();
					break;
				}

				try {
					OutputLine outputLine = outputQueue.poll(remaining, TimeUnit.MILLISECONDS);
					if (outputLine == null) {
						timedOut = true;
						restart();
						break;
					}

					// Skip EOF markers
					if (outputLine.content == null) {
						continue;
					}

					String line = outputLine.content;

View on GitHub (pinned to f82da0b50f)

Solutions

1. Increase the command timeout in the shell tool configuration if the workload legitimately needs longer.
2. Fix the command: add its own timeout (e.g. 'timeout 60 <cmd>'), redirect stdin from /dev/null for non-interactive use.
3. Split long work into smaller commands the agent can run sequentially.
4. Note the session was restarted; re-run any stateful setup (cd, exports) that the restart discarded.

Example fix

// before
shell.execute("npm install");
// after
shell.execute("timeout 600 npm install"); // plus raise configured timeout

if (result.timedOut()) { log.warn("Command {} timed out; session restarted", cmd); /* re-init session state and retry with longer timeout */ }

When it happens

Trigger: Running a long-running or blocking command (infinite loop, waiting on stdin, network hang) through execute so that no output line arrives before the deadline in outputQueue.poll.

Common situations: Agent asks the shell to run 'sleep 1000', an interactive command that blocks on input, or a command stuck on a network call exceeding the session's timeout setting.

Understand the failure class

Background: Request timed out: what client-side request timeouts mean across libraries (Request timed out, TIMED_OUT, APITimeoutError) — this error's family across 39 libraries.

• Timeouts: ETIMEDOUT, deadlines, and hung requests — what actually expires when a request times out.

Related errors

• Startup command failed:
• Failed to initialize shell session
• Failed to restart shell session
• Shell session is not running
• Failed to execute command

AI-assisted analysis of alibaba/spring-ai-alibaba@f82da0b50f (2026-09-09). Data as JSON: /api/errors/d2e8bb624272c654. Report an issue: GitHub.