XX-net/XX-Net · info · NotSupported

NotSupported

Error message

NotSupported

What it means

NotSupported(req, sock) is raised from do_gae when the incoming HTTP request asks for a WebSocket upgrade (req.upgrade == b'websocket'). GAE operates as an HTTP/HTTPS relay over Google App Engine and cannot carry raw bidirectional WebSocket frames, so the router raises NotSupported to signal try_loop to try a different strategy (e.g. direct or X-Tunnel).

Source

Thrown at code/default/smart_router/local/smart_route.py:344

    if req.path[0] == b'/':
        url = b'%s://%s%s' % (schema, req.headers[b'Host'], req.path)
    else:
        url = req.path

    if url in [b"http://www.twitter.com/xxnet",
                    b"https://www.twitter.com/xxnet",
                    b"http://www.deja.com/xxnet",
                    b"https://www.deja.com/xxnet"
                    ]:
        # for web_ui status page
        # auto detect browser proxy setting is work
        xlog.debug("CONNECT %s %s", req.command, req.path)
        req.wfile.write(req.self_check_response_data)
        return

    if req.upgrade == b"websocket":
        xlog.debug("gae %s not support WebSocket", req.path)
        raise NotSupported(req, sock)

    if len(req.path) >= 2048:
        xlog.debug("gae %s path len exceed 1024 limit", req.path)
        raise NotSupported(req, sock)

    if req.command not in req.gae_support_methods:
        xlog.debug("gae %s %s, method not supported", req.command, req.path)
        raise NotSupported(req, sock)

    req.parsed_url = urlparse(req.path)
    req.do_METHOD()


def try_loop(scense, rule_list, sock, host, port, client_address, left_buf=""):
    xlog.debug("try_loop %s %s to %s:%d", scense, rule_list, host, port)

    start_time = time.time()

View on GitHub (pinned to cfa5bc17b6)

Solutions

1. Add a routing rule that sends WebSocket traffic to direct or X-Tunnel instead of GAE
2. Catch NotSupported in try_loop so the connection falls back to a WebSocket-capable strategy (designed behavior)
3. If WebSockets are essential, consider disabling the GAE strategy for the affected hosts

if req.headers.get('Upgrade','').lower() == 'websocket':
    skip_strategy('gae')

try:
    do_gae(...)
except NotSupported:
    try_next_strategy(sock, host, port)  # direct/X-Tunnel support websockets

When it happens

Trigger: A client opens a WebSocket connection (Upgrade: websocket header) and the smart router routes it to the GAE strategy.

Common situations: Browsers/applications using WebSocket-based services (chat, live feeds) while GAE is the first matching routing rule.

Related errors

• time out
• 600
• fetch gae fail:%d
• 602
• 605

AI-assisted analysis of XX-net/XX-Net@cfa5bc17b6 (2026-08-27). Data as JSON: /api/errors/6adf64ba4eda6a23. Report an issue: GitHub.