Method handleRequest

src/Server/HTTPHandler.cpp:716–823

}

void HTTPHandler::handleRequest(HTTPServerRequest & request, HTTPServerResponse & response, const ProfileEvents::Event & write_event)
{
    DB::setThreadName(ThreadName::HTTP_HANDLER);

    session = std::make_unique<Session>(server.context(), ClientInfo::Interface::HTTP, request.isSecure());
    SCOPE_EXIT({ session.reset(); });
    QueryScope query_scope;

    Output used_output;

    /// In case of exception, send stack trace to client.
    bool with_stacktrace = false;

    OpenTelemetry::TracingContextHolderPtr thread_trace_context;
    SCOPE_EXIT({
        // make sure the response status is recorded
        if (thread_trace_context)
            thread_trace_context->root_span.addAttribute("clickhouse.http_status", response.getStatus());
    });

    try
    {
        if (request.getMethod() == HTTPServerRequest::HTTP_OPTIONS)
        {
            processOptionsRequest(response, server.config());
            return;
        }

        // Parse the OpenTelemetry traceparent header.
        auto & client_trace_context = session->getClientTraceContext();
        if (request.has("traceparent"))
        {
            std::string opentelemetry_traceparent = request.get("traceparent");
            std::string error;
            if (!client_trace_context.parseTraceparentHeader(opentelemetry_traceparent, error))
            {
                LOG_DEBUG(log, "Failed to parse OpenTelemetry traceparent header '{}': {}", opentelemetry_traceparent, error);
            }
            client_trace_context.tracestate = request.get("tracestate", "");
        }

        // Setup tracing context for this thread
        auto context = session->sessionOrGlobalContext();
        thread_trace_context = std::make_unique<OpenTelemetry::TracingContextHolder>("HTTPHandler",
            client_trace_context,
            context->getSettingsRef(),
            context->getOpenTelemetrySpanLog());
        thread_trace_context->root_span.kind = OpenTelemetry::SpanKind::SERVER;
        thread_trace_context->root_span.addAttribute("clickhouse.uri", request.getURI());
        thread_trace_context->root_span.addAttribute("http.referer", request.get("Referer", ""));
        thread_trace_context->root_span.addAttribute("http.user.agent", request.get("User-Agent", ""));
        thread_trace_context->root_span.addAttribute("http.method", request.getMethod());

        response.setContentType("text/plain; charset=UTF-8");
        response.add("Access-Control-Expose-Headers", "X-ClickHouse-Query-Id,X-ClickHouse-Summary,X-ClickHouse-Server-Display-Name,X-ClickHouse-Format,X-ClickHouse-Timezone,X-ClickHouse-Exception-Code,X-ClickHouse-Exception-Tag");
        response.set("X-ClickHouse-Server-Display-Name", server_display_name);

        if (!request.get("Origin", "").empty())