prestodb/presto · error · IllegalArgumentException

Invalid header name: %s

Error message

Invalid header name: %s

What it means

AsyncPageTransportServlet.parseURI rejects a request header whose name fails HTTP header-name validation while forwarding extra headers into the page response; the offending name is included and the request is answered with 400 Bad Request.

Source

Thrown at presto-main/src/main/java/com/facebook/presto/server/AsyncPageTransportServlet.java:137

        response.sendError(SC_BAD_REQUEST, message);
    }

    protected void parseURI(String requestURI, HttpServletRequest request, HttpServletResponse response)
            throws IOException
    {
        // Split a task URI without allocating a list and unnecessary strings
        // Example:  /v1/task/async/{taskId}/results/{bufferId}/{token}
        TaskId taskId = null;
        OutputBufferId bufferId = null;
        long token = 0;

        if (request != null) {
            Enumeration<String> headerNames = request.getHeaderNames();
            while (headerNames.hasMoreElements()) {
                String headerName = headerNames.nextElement();
                String headerValue = request.getHeader(headerName);
                if (headerName.contains("\r") || headerName.contains("\n")) {
                    throw new IllegalArgumentException(format("Invalid header name: %s", headerName));
                }
                if (headerValue.contains("\r") || headerValue.contains("\n")) {
                    throw new IllegalArgumentException(format("Invalid header value: %s", headerValue));
                }
            }
        }

        int previousIndex = -1;
        for (int part = 0; part < 8; part++) {
            int nextIndex = requestURI.indexOf('/', previousIndex + 1);

            if (nextIndex == -1 && part != 7 || nextIndex != -1 && part == 7) {
                reportFailure(response, format("Unexpected URI for task result request in async mode: %s", requestURI));
                return;
            }

            switch (part) {
                case 4:

View on GitHub (pinned to 55bb57d202)

Solutions

1. Fix the client/proxy that injects the malformed header name

When it happens

Trigger: Thrown at presto-main/src/main/java/com/facebook/presto/server/AsyncPageTransportServlet.java:137 when the library encounters an invalid state.

Common situations: See trigger scenarios.

AI-assisted analysis of prestodb/presto@55bb57d202 (2026-09-04). Data as JSON: /api/errors/f910accf0d5da317. Report an issue: GitHub.