alibaba/arthas · error · ApiException

session not found: {}

Error message

session not found: {}

What it means

Thrown when a sessionId is provided but sessionManager.getSession() returns null — the session does not exist. This means the session was never created, was already closed, or expired due to inactivity timeout.

Source

Thrown at core/src/main/java/com/taobao/arthas/core/shell/term/impl/http/api/HttpApiHandler.java:146

            }

            //no session required
            if (ApiAction.INIT_SESSION.equals(action)) {
                return processInitSessionRequest(apiRequest);
            }

            //required session
            Session session = null;
            boolean allowNullSession = ApiAction.EXEC.equals(action);
            String sessionId = apiRequest.getSessionId();
            if (StringUtils.isBlank(sessionId)) {
                if (!allowNullSession) {
                    throw new ApiException("'sessionId' is required");
                }
            } else {
                session = sessionManager.getSession(sessionId);
                if (session == null) {
                    throw new ApiException("session not found: " + sessionId);
                }
                sessionManager.updateAccessTime(session);
            }

            // 标记所谓的一次性session
            if (session == null) {
                session = sessionManager.createSession();
                session.put(ONETIME_SESSION_KEY, new Object());
            }

            // 请求到达这里，如果有需要鉴权，则已经在前面的handler里处理过了
            // 如果有鉴权取到的 Subject，则传递到 arthas的session里
            HttpSession httpSession = HttpSessionManager.getHttpSessionFromContext(ctx);
            if (httpSession != null) {
                Object subject = httpSession.getAttribute(ArthasConstants.SUBJECT_KEY);
                if (subject != null) {
                    session.put(ArthasConstants.SUBJECT_KEY, subject);
                }

View on GitHub (pinned to 21cf2e9ba5)

Solutions

1. Call INIT_SESSION to obtain a fresh sessionId and use it going forward.
2. Ensure API calls happen within the session timeout window (configure connectionTimeout/sessionTimeout).
3. Handle this error in client code by automatically re-initializing the session.

Example fix

// client retry logic
try {
    callApi(action, sessionId, ...);
} catch (ApiException e) {
    if (e.getMessage().contains("session not found")) {
        sessionId = initSession();  // re-init
        callApi(action, sessionId, ...);
    }
}

// Client-side: check session is still alive before use
// (no direct API; rely on INIT_SESSION + caching with expiry)

try {
    response = callApi(action, sessionId);
} catch (ApiException e) {
    if (e.getMessage().contains("session not found")) {
        sessionId = initSession();
        response = callApi(action, sessionId); // retry once
    } else throw e;
}

When it happens

Trigger: Using a sessionId from a session that was closed via CLOSE_SESSION, that timed out (session expiration), from a previous Arthas lifecycle, or simply a fabricated/typo'd sessionId.

Common situations: Stale sessionId cached by the client after the session expired. Long gaps between API calls exceeding the session timeout. Arthas was restarted (in-process), invalidating all sessions.

Related errors

• 'sessionId' is required
• create api session failed
• consumer not found: {}
• SessionId is required for this operation
• Failed to create temporary session

AI-assisted analysis of alibaba/arthas@21cf2e9ba5 (2026-08-14). Data as JSON: /api/errors/44dfc42f79a73f77. Report an issue: GitHub.