Failed at generating thumbnail SoftTimeLimitExceeded()

[shaymongracia]

does someone getting this SoftTimeLimitExceeded, I'm trying to get the thumbnails and reports but when I check celery logs I saw a bunch of SoftTimeLimitExceeded. I'm wondering what could be causing it, I see that navigating to the path /login/ it takes long

I did change the WEBDRIVER_BASEURL to WEBDRIVER_BASEURL = "http://localhost:8088" and WEBDRIVER_BASEURL = "http://0.0.0.0:8088" but seems to be no difference

in this server we are running Superset 4.1.2 with Python 3.10 and Ubuntu 24.04
this server due to security reasons have no internet access but the request should be localhost only so I don't see this could be the reason for the timeout.

[2025-07-07 18:57:23,430: INFO/ForkPoolWorker-1] Caching chart: http://localhost:8088/superset/slice/191/
[2025-07-07 18:57:23,449: INFO/ForkPoolWorker-1] Processing url for thumbnail: 4592528f0d18139c7834172617a35607
[2025-07-07 18:57:23,450: DEBUG/ForkPoolWorker-1] Init selenium driver
[2025-07-07 18:57:23,453: DEBUG/ForkPoolWorker-1] Started executable: `/usr/bin/chromedriver` in a child process with pid: 2788065
[2025-07-07 18:57:23,957: DEBUG/ForkPoolWorker-1] POST http://localhost:58885/session {"capabilities": {"firstMatch": [{}], "alwaysMatch": {"browserName": "chrome", "pageLoadStrategy": "normal", "goog:chromeOptions": {"extensions": [], "args": ["--force-device-scale-factor=1", "--window-size=800,600", "--no-sandbox", "--disable-infobars", "--force-device-scale-factor=2.0", "--high-dpi-support=2.0", "--headless", "--disable-gpu", "--disable-dev-shm-usage", "--disable-setuid-sandbox", "--disable-extensions", "--enable-logging", "--v=1", "--ignore-certificate-errors"]}}}}
[2025-07-07 18:57:23,959: DEBUG/ForkPoolWorker-1] Starting new HTTP connection (1): localhost:58885
[2025-07-07 18:57:24,303: DEBUG/ForkPoolWorker-1] http://localhost:58885 "POST /session HTTP/11" 200 0
[2025-07-07 18:57:24,303: DEBUG/ForkPoolWorker-1] Remote response: status=200 | data={"value":{"capabilities":{"acceptInsecureCerts":false,"browserName":"chrome","browserVersion":"138.0.7204.49","chrome":{"chromedriverVersion":"138.0.7204.49 (d2b48fd5f7813ed477a2d68fa232b8178fa4fb1e-refs/branch-heads/7204@{#1814})","userDataDir":"/tmp/.org.chromium.Chromium.xH8kHz"},"fedcm:accounts":true,"goog:chromeOptions":{"debuggerAddress":"localhost:38717"},"networkConnectionEnabled":false,"pageLoadStrategy":"normal","platformName":"linux","proxy":{},"setWindowRect":true,"strictFileInteractability":false,"timeouts":{"implicit":0,"pageLoad":300000,"script":30000},"unhandledPromptBehavior":"dismiss and notify","webauthn:extension:credBlob":true,"webauthn:extension:largeBlob":true,"webauthn:extension:minPinLength":true,"webauthn:extension:prf":true,"webauthn:virtualAuthenticators":true},"sessionId":"7d627536850218592fdd701b7d7acd3e"}} | headers=HTTPHeaderDict({'Content-Length': '848', 'Content-Type': 'application/json; charset=utf-8', 'cache-control': 'no-cache'})
[2025-07-07 18:57:24,303: DEBUG/ForkPoolWorker-1] Finished Request
[**2025-07-07 18:57:24,303**: DEBUG/ForkPoolWorker-1] POST http://localhost:58885/session/7d627536850218592fdd701b7d7acd3e/url {"url": "http://localhost:8088/login/"}
[2025-07-07 19:01:25,873: DEBUG/ForkPoolWorker-1] http://localhost:58885 "POST /session/7d627536850218592fdd701b7d7acd3e/url HTTP/11" 200 0
[**2025-07-07 19:01:25,874**: DEBUG/ForkPoolWorker-1] Remote response: status=200 | data={"value":null} | headers=HTTPHeaderDict({'Content-Length': '14', 'Content-Type': 'application/json; charset=utf-8', 'cache-control': 'no-cache'})
[2025-07-07 19:01:25,874: DEBUG/ForkPoolWorker-1] Finished Request
[2025-07-07 19:01:25,879: DEBUG/ForkPoolWorker-1] POST http://localhost:58885/session/7d627536850218592fdd701b7d7acd3e/cookie {"cookie": {"name": "session", "value": ".eJwlzjE...."}}
[2025-07-07 19:01:25,895: DEBUG/ForkPoolWorker-1] http://localhost:58885 "POST /session/7d627536850218592fdd701b7d7acd3e/cookie HTTP/11" 200 0
[2025-07-07 19:01:25,896: DEBUG/ForkPoolWorker-1] Remote response: status=200 | data={"value":null} | headers=HTTPHeaderDict({'Content-Length': '14', 'Content-Type': 'application/json; charset=utf-8', 'cache-control': 'no-cache'})
[2025-07-07 19:01:25,896: DEBUG/ForkPoolWorker-1] Finished Request
[2025-07-07 19:01:25,896: DEBUG/ForkPoolWorker-1] POST http://localhost:58885/session/7d627536850218592fdd701b7d7acd3e/window/rect {"x": null, "y": null, "width": 800, "height": 600}
[2025-07-07 19:01:25,904: DEBUG/ForkPoolWorker-1] http://localhost:58885 "POST /session/7d627536850218592fdd701b7d7acd3e/window/rect HTTP/11" 200 0
[2025-07-07 19:01:25,904: DEBUG/ForkPoolWorker-1] Remote response: status=200 | data={"value":{"height":600,"width":800,"x":10,"y":10}} | headers=HTTPHeaderDict({'Content-Length': '50', 'Content-Type': 'application/json; charset=utf-8', 'cache-control': 'no-cache'})
[2025-07-07 19:01:25,904: DEBUG/ForkPoolWorker-1] Finished Request
[2025-07-07 19:01:25,904: DEBUG/ForkPoolWorker-1] POST http://localhost:58885/session/7d627536850218592fdd701b7d7acd3e/url {"url": "http://localhost:8088/superset/slice/191/?standalone=true"}
[2025-07-07 19:02:23,238: WARNING/MainProcess] Soft time limit (300s) exceeded for cache_chart_thumbnail[f7d45e43-3fd5-46fe-a0d8-7b2a3096ddfa]
[2025-07-07 19:02:23,239: WARNING/ForkPoolWorker-1] Failed at generating thumbnail SoftTimeLimitExceeded()
Traceback (most recent call last):
  File "/app/superset/superset_env/lib/python3.10/site-packages/superset/utils/screenshots.py", line 172, in compute_and_cache
  File "/app/superset/superset_env/lib/python3.10/site-packages/superset/utils/screenshots.py", line 94, in get_screenshot
  File "/app/superset/superset_env/lib/python3.10/site-packages/superset/utils/webdriver.py", line 356, in get_screenshot
  File "/app/superset/superset_env/lib/python3.10/site-packages/selenium/webdriver/remote/webdriver.py", line 449, in get
  File "/app/superset/superset_env/lib/python3.10/site-packages/selenium/webdriver/remote/webdriver.py", line 438, in execute
  File "/app/superset/superset_env/lib/python3.10/site-packages/selenium/webdriver/remote/remote_connection.py", line 290, in execute
  File "/app/superset/superset_env/lib/python3.10/site-packages/selenium/webdriver/remote/remote_connection.py", line 311, in _request
  File "/app/superset/superset_env/lib/python3.10/site-packages/urllib3/_request_methods.py", line 143, in request
  File "/app/superset/superset_env/lib/python3.10/site-packages/urllib3/_request_methods.py", line 278, in request_encode_body
  File "/app/superset/superset_env/lib/python3.10/site-packages/urllib3/poolmanager.py", line 443, in urlopen
  File "/app/superset/superset_env/lib/python3.10/site-packages/urllib3/connectionpool.py", line 789, in urlopen
  File "/app/superset/superset_env/lib/python3.10/site-packages/urllib3/connectionpool.py", line 536, in _make_request
  File "/app/superset/superset_env/lib/python3.10/site-packages/urllib3/connection.py", line 507, in getresponse
  File "/usr/lib/python3.10/http/client.py", line 1375, in getresponse
  File "/usr/lib/python3.10/http/client.py", line 318, in begin
  File "/usr/lib/python3.10/http/client.py", line 279, in _read_status
  File "/usr/lib/python3.10/socket.py", line 705, in readinto
  File "/app/superset/superset_env/lib/python3.10/site-packages/billiard/pool.py", line 228, in soft_timeout_sighandler
billiard.exceptions.SoftTimeLimitExceeded: SoftTimeLimitExceeded()

[dosubot[bot]]

Hi @shaymongracia! I'm Dosu and I’m helping the superset team.

The SoftTimeLimitExceeded errors are happening because the Celery task for generating thumbnails is waiting too long for the /login/ page to load—this is a required step for Selenium to inject the session cookie before accessing the chart or dashboard. If /login/ is slow, the whole screenshot process stalls and eventually hits the 5-minute soft time limit set for the task, causing it to fail code reference.

Common causes for slow /login/ in this context are: a slow session backend (like a database or Redis), static asset loading issues, cookie misconfiguration (domain, samesite, etc.), or server resource constraints. In isolated environments, missing or misconfigured static assets or session storage can also cause delays discussion.

Here’s what you can do:

• Test /login/ directly from the Celery worker host using curl or wget to see if it’s slow outside of Selenium.
• Check your Superset and web server logs for errors or warnings when /login/ is accessed.
• Make sure your session backend (DB, Redis, etc.) is healthy and fast.
• Confirm that all static assets are present and served locally—missing assets can cause long waits.
• Double-check your cookie/session domain and samesite settings, especially if you’re using containers or have changed WEBDRIVER_BASEURL.
• Ensure your Selenium/ChromeDriver config is fully local. Superset ignores WEBDRIVER_EXECUTABLE_PATH; you must set the path via WEBDRIVER_CONFIGURATION['service']['executable_path'] in superset_config.py to avoid Selenium trying to download ChromeDriver from the internet discussion.

If you can’t immediately resolve the slowness, you can try increasing SCREENSHOT_LOCATE_WAIT and SCREENSHOT_LOAD_WAIT in superset_config.py to give Selenium more time, but this only helps if the server is just slow, not stuck discussion.

If /login/ is slow even with a direct HTTP request, focus on fixing the web server or session backend. If it’s only slow in Selenium, look at network/cookie config or container networking. Let me know if you find anything specific in the logs or if you need help with config details.

To reply, just mention @dosu.

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