Fix memory accounting via HTTP interface

src/Server/HTTPHandler.cpp

@@ -232,15 +232,12 @@ HTTPHandler::HTTPHandler(IServer & server_, const std::string & name)
 
 
 void HTTPHandler::processQuery(
+    Context & context,
     Poco::Net::HTTPServerRequest & request,
     HTMLForm & params,
     Poco::Net::HTTPServerResponse & response,
     Output & used_output)
 {
-    Context context = server.context();
-
-    CurrentThread::QueryScope query_scope(context);
-
     LOG_TRACE(log, "Request URI: {}", request.getURI());
 
     std::istream & istr = request.stream();
@@ -683,6 +680,11 @@ void HTTPHandler::handleRequest(Poco::Net::HTTPServerRequest & request, Poco::Ne
     setThreadName("HTTPHandler");
     ThreadStatus thread_status;
 
+    /// Should be initialized before anything,
+    /// For correct memory accounting.
+    Context context = server.context();
+    CurrentThread::QueryScope query_scope(context);
+
     Output used_output;
 
     /// In case of exception, send stack trace to client.
@@ -706,7 +708,7 @@ void HTTPHandler::handleRequest(Poco::Net::HTTPServerRequest & request, Poco::Ne
             throw Exception("The Transfer-Encoding is not chunked and there is no Content-Length header for POST request", ErrorCodes::HTTP_LENGTH_REQUIRED);
         }
 
-        processQuery(request, params, response, used_output);
+        processQuery(context, request, params, response, used_output);
         LOG_INFO(log, "Done processing query");
     }
     catch (...)

src/Server/HTTPHandler.h

@@ -72,6 +72,7 @@ class HTTPHandler : public Poco::Net::HTTPRequestHandler
 
     /// Also initializes 'used_output'.
     void processQuery(
+        Context & context,
         Poco::Net::HTTPServerRequest & request,
         HTMLForm & params,
         Poco::Net::HTTPServerResponse & response,

tests/queries/0_stateless/01238_http_memory_tracking.reference

@@ -0,0 +1 @@
+10000

tests/queries/0_stateless/01238_http_memory_tracking.sh

@@ -0,0 +1,26 @@
+#!/usr/bin/env bash
+
+CURDIR=$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)
+. $CURDIR/../shell_config.sh
+
+# TODO: the test can be way more optimal
+
+set -o pipefail
+
+function execute_null()
+{
+    ${CLICKHOUSE_CLIENT} --format Null -n "$@"
+}
+
+# This is needed to keep at least one running query for user for the time of test.
+# (10k http queries takes 10seconds, let's run for 3x more to avoid flaps)
+execute_null <<<'SELECT sleepEachRow(1) FROM numbers(30)' &
+
+# ignore "yes: standard output: Broken pipe"
+yes 'SELECT 1' 2>/dev/null | {
+    head -n10000
+} | {
+    xargs -P10000 -i ${CLICKHOUSE_CURL} -sS "${CLICKHOUSE_URL}&wait_end_of_query=1&max_memory_usage_for_user=$((10<<30))" -d '{}'
+} | grep -x -c 1
+
+wait