add keepalive_timeout flag (#6674)

* add keepalive_timeout flag

CHANGELOG.md

@@ -1,6 +1,7 @@
 # Unreleased
   - Changes from 5.27.1
     - Features
+      - ADDED: Add support for a keepalive_timeout flag. [#6674](https://github.com/Project-OSRM/osrm-backend/pull/6674)
       - ADDED: Add support for a default_radius flag. [#6575](https://github.com/Project-OSRM/osrm-backend/pull/6575)
       - ADDED: Add support for disabling feature datasets. [#6666](https://github.com/Project-OSRM/osrm-backend/pull/6666)
     - Build:

features/options/routed/help.feature

@@ -23,6 +23,7 @@ Feature: osrm-routed command line options: help
         And stdout should contain "--max-table-size"
         And stdout should contain "--max-matching-size"
         And stdout should contain "--default-radius"
+        And stdout should contain "--keepalive-timeout"
         And it should exit successfully
 
     Scenario: osrm-routed - Help, short
@@ -44,6 +45,7 @@ Feature: osrm-routed command line options: help
         And stdout should contain "--max-table-size"
         And stdout should contain "--max-matching-size"
         And stdout should contain "--default-radius"
+        And stdout should contain "--keepalive-timeout"
         And it should exit successfully
 
     Scenario: osrm-routed - Help, long
@@ -65,4 +67,5 @@ Feature: osrm-routed command line options: help
         And stdout should contain "--max-table-size"
         And stdout should contain "--max-matching-size"
         And stdout should contain "--default-radius"
+        And stdout should contain "--keepalive-timeout"
         And it should exit successfully

include/server/connection.hpp

@@ -35,7 +35,9 @@ class RequestHandler;
 class Connection : public std::enable_shared_from_this<Connection>
 {
   public:
-    explicit Connection(boost::asio::io_context &io_context, RequestHandler &handler);
+    explicit Connection(boost::asio::io_context &io_context,
+                        RequestHandler &handler,
+                        short keepalive_timeout);
     Connection(const Connection &) = delete;
     Connection &operator=(const Connection &) = delete;
 

include/server/server.hpp

@@ -31,18 +31,24 @@ class Server
 {
   public:
     // Note: returns a shared instead of a unique ptr as it is captured in a lambda somewhere else
-    static std::shared_ptr<Server>
+    static std::shared_ptr<Server> CreateServer(std::string &ip_address,
-    CreateServer(std::string &ip_address, int ip_port, unsigned requested_num_threads)
+                                                int ip_port,
+                                                unsigned requested_num_threads,
+                                                short keepalive_timeout)
     {
         util::Log() << "http 1.1 compression handled by zlib version " << zlibVersion();
         const unsigned hardware_threads = std::max(1u, std::thread::hardware_concurrency());
         const unsigned real_num_threads = std::min(hardware_threads, requested_num_threads);
-        return std::make_shared<Server>(ip_address, ip_port, real_num_threads);
+        return std::make_shared<Server>(ip_address, ip_port, real_num_threads, keepalive_timeout);
     }
 
-    explicit Server(const std::string &address, const int port, const unsigned thread_pool_size)
+    explicit Server(const std::string &address,
-        : thread_pool_size(thread_pool_size), acceptor(io_context),
+                    const int port,
-          new_connection(std::make_shared<Connection>(io_context, request_handler))
+                    const unsigned thread_pool_size,
+                    const short keepalive_timeout)
+        : thread_pool_size(thread_pool_size), keepalive_timeout(keepalive_timeout),
+          acceptor(io_context), new_connection(std::make_shared<Connection>(
+                                    io_context, request_handler, keepalive_timeout))
     {
         const auto port_string = std::to_string(port);
 
@@ -94,7 +100,8 @@ class Server
         if (!e)
         {
             new_connection->start();
-            new_connection = std::make_shared<Connection>(io_context, request_handler);
+            new_connection =
+                std::make_shared<Connection>(io_context, request_handler, keepalive_timeout);
             acceptor.async_accept(
                 new_connection->socket(),
                 boost::bind(&Server::HandleAccept, this, boost::asio::placeholders::error));
@@ -107,6 +114,7 @@ class Server
 
     RequestHandler request_handler;
     unsigned thread_pool_size;
+    short keepalive_timeout;
     boost::asio::io_context io_context;
     boost::asio::ip::tcp::acceptor acceptor;
     std::shared_ptr<Connection> new_connection;

src/server/connection.cpp

@@ -7,14 +7,17 @@
 #include <boost/iostreams/filter/gzip.hpp>
 #include <boost/iostreams/filtering_stream.hpp>
 
+#include <fmt/format.h>
 #include <vector>
 
 namespace osrm::server
 {
 
-Connection::Connection(boost::asio::io_context &io_context, RequestHandler &handler)
+Connection::Connection(boost::asio::io_context &io_context,
+                       RequestHandler &handler,
+                       short keepalive_timeout)
     : strand(boost::asio::make_strand(io_context)), TCP_socket(strand), timer(strand),
-      request_handler(handler)
+      request_handler(handler), keepalive_timeout(keepalive_timeout)
 {
 }
 
@@ -88,7 +91,9 @@ void Connection::handle_read(const boost::system::error_code &error, std::size_t
         {
             keep_alive = true;
             current_reply.headers.emplace_back("Connection", "keep-alive");
-            current_reply.headers.emplace_back("Keep-Alive", "timeout=5, max=512");
+            current_reply.headers.emplace_back("Keep-Alive",
+                                               "timeout=" + fmt::to_string(keepalive_timeout) +
+                                                   ", max=" + fmt::to_string(processed_requests));
         }
 
         // compress the result w/ gzip/deflate if requested

src/tools/routed.cpp

@@ -107,7 +107,8 @@ inline unsigned generateServerProgramOptions(const int argc,
                                              int &ip_port,
                                              bool &trial,
                                              EngineConfig &config,
-                                             int &requested_thread_num)
+                                             int &requested_thread_num,
+                                             short &keepalive_timeout)
 {
     using boost::filesystem::path;
     using boost::program_options::value;
@@ -140,6 +141,9 @@ inline unsigned generateServerProgramOptions(const int argc,
         ("threads,t",
          value<int>(&requested_thread_num)->default_value(hardware_threads),
          "Number of threads to use") //
+        ("keepalive-timeout,k",
+         value<short>(&keepalive_timeout)->default_value(5),
+         "Default keepalive-timeout. Default: 5 seconds.") //
         ("shared-memory,s",
          value<bool>(&config.use_shared_memory)->implicit_value(true)->default_value(false),
          "Load data from shared memory") //
@@ -266,8 +270,16 @@ try
     boost::filesystem::path base_path;
 
     int requested_thread_num = 1;
-    const unsigned init_result = generateServerProgramOptions(
+    short keepalive_timeout = 5;
-        argc, argv, base_path, ip_address, ip_port, trial_run, config, requested_thread_num);
+    const unsigned init_result = generateServerProgramOptions(argc,
+                                                              argv,
+                                                              base_path,
+                                                              ip_address,
+                                                              ip_port,
+                                                              trial_run,
+                                                              config,
+                                                              requested_thread_num,
+                                                              keepalive_timeout);
     if (init_result == INIT_OK_DO_NOT_START_ENGINE)
     {
         return EXIT_SUCCESS;
@@ -307,6 +319,7 @@ try
     util::Log() << "Threads: " << requested_thread_num;
     util::Log() << "IP address: " << ip_address;
     util::Log() << "IP port: " << ip_port;
+    util::Log() << "Keepalive timeout: " << keepalive_timeout;
 
 #ifndef _WIN32
     int sig = 0;
@@ -319,7 +332,8 @@ try
 #endif
 
     auto service_handler = std::make_unique<server::ServiceHandler>(config);
-    auto routing_server = server::Server::CreateServer(ip_address, ip_port, requested_thread_num);
+    auto routing_server =
+        server::Server::CreateServer(ip_address, ip_port, requested_thread_num, keepalive_timeout);
 
     routing_server->RegisterServiceHandler(std::move(service_handler));