prestodb/presto · error · ClientException

Invalid server URL:

Error message

Invalid server URL: 

What it means

buildQueryRequest parses session.getServer() with OkHttp's HttpUrl.get, which returns null for URLs that are not valid absolute HTTP(S) URLs; the code then throws ClientException 'Invalid server URL: <url>'. The library cannot even construct the /v1/statement request because the server address is malformed.

Source

Thrown at presto-client/src/main/java/com/facebook/presto/client/StatementClientV1.java:151

        this.validateNextUriSource = session.validateNextUriSource();

        Request request = buildQueryRequest(session, query);

        JsonResponse<QueryResults> response = JsonResponse.execute(QUERY_RESULTS_CODEC, httpClient, request);
        if ((response.getStatusCode() != HTTP_OK) || !response.hasValue()) {
            state.compareAndSet(State.RUNNING, State.CLIENT_ERROR);
            throw requestFailedException("starting query", request, response);
        }

        processResponse(response.getHeaders(), response.getValue());
        this.responseHeaders = toHeaderMap(response.getHeaders());
    }

    private Request buildQueryRequest(ClientSession session, String query)
    {
        HttpUrl url = HttpUrl.get(session.getServer());
        if (url == null) {
            throw new ClientException("Invalid server URL: " + session.getServer());
        }
        url = url.newBuilder().encodedPath("/v1/statement").build();

        Request.Builder builder = prepareRequest(url)
                .post(RequestBody.create(MEDIA_TYPE_TEXT, query));

        Map<String, String> customHeaders = session.getCustomHeaders();
        for (Entry<String, String> entry : customHeaders.entrySet()) {
            builder.addHeader(entry.getKey(), entry.getValue());
        }

        if (session.getSource() != null) {
            builder.addHeader(PRESTO_SOURCE, session.getSource());
        }

        session.getTraceToken().ifPresent(token -> builder.addHeader(PRESTO_TRACE_TOKEN, token));

        if (session.getClientTags() != null && !session.getClientTags().isEmpty()) {

View on GitHub (pinned to 55bb57d202)

Solutions

1. Include an explicit scheme: http://host:port or https://host:port.
2. Print/inspect the server string actually passed (check env vars and config substitution).
3. Validate the URL with HttpUrl.get(...) or `new URL(...)` before constructing the client.
4. Remove whitespace or invalid characters from the server setting.

Example fix

// before
presto --server presto.example.com:8080
// after
presto --server http://presto.example.com:8080

String server = session.getServer();
if (server == null || !server.matches("^https?://[^\s]+$")) {
    throw new IllegalArgumentException("Server must be an absolute http(s) URL: " + server);
}

try { client.startQuery(session, sql); } catch (ClientException e) { if (e.getMessage().startsWith("Invalid server URL")) { /* fix server config and retry */ } throw e; }

When it happens

Trigger: Creating a StatementClientV1 (presto CLI/JDBC startQuery) with a session server string like 'presto.example.com:8080' (no scheme), 'http:/host' (malformed), or containing illegal characters.

Common situations: Forgetting the http:// or https:// scheme; trailing typos or spaces in the --server argument; environment variable/POM substitution leaving a placeholder like ${PRESTO_SERVER}; using ftp:// or a bare hostname.

Understand the failure class

Background: "Invalid URL" / "URL cannot be empty": fix the malformed or missing URL behind request-construction failures — this error's family across 50 libraries.

Related errors

• Illegal character ':' found in username
• Error setting up SSL:
• ACCUMULO_TABLE_EXISTS
• UNEXPECTED_ACCUMULO_ERROR
• NOT_SUPPORTED

AI-assisted analysis of prestodb/presto@55bb57d202 (2026-09-04). Data as JSON: /api/errors/dddc09977fa4c793. Report an issue: GitHub.