Retry connecting 5 times, 3, 6, 12, 24, 48 and 96 seconds between attempts

1 files changed, 45 insertions, 7 deletions

diff --git a/libcmix-network/connect.cpp b/libcmix-network/connect.cpp
index f25ae24..6f1addf 100644
--- a/libcmix-network/connect.cpp
+++ b/libcmix-network/connect.cpp
@@ -29,21 +29,57 @@ boost::asio::ip::tcp::socket connect(std::string host, std::string port, io_serv
 	throw std::runtime_error("None of the supplied endpoints responded");
 }
 
-void async_connect_iteration(tcp::socket& socket, boost::asio::ip::tcp::resolver::iterator it, std::function<void()> on_connect) {
-	if(it == boost::asio::ip::tcp::resolver::iterator()) {
+struct IterationInfo {
+	int iteration;
+	boost::asio::ip::tcp::resolver::iterator it;
+	boost::asio::deadline_timer retry_timer;
+	
+	IterationInfo(int iteration, boost::asio::ip::tcp::resolver::iterator it, boost::asio::io_service& io_service)
+	: iteration(iteration)
+	, it(it)
+	, retry_timer(io_service)
+	{}
+};
+
+void async_connect_iteration(tcp::socket& socket, std::shared_ptr<IterationInfo> info, std::function<void()> on_connect) {
+	
+	if(info->it == boost::asio::ip::tcp::resolver::iterator()) {
 		throw std::runtime_error("None of the supplied endpoints responded");
 	} 
 	
-	auto handler = [&socket, it, on_connect](boost::system::error_code const& ec) {
-		if(ec) {
+	auto handler = [&socket, info, on_connect](boost::system::error_code const& ec) {
+		if(ec == boost::system::errc::connection_refused) {
+			socket.close();
+			if(info->iteration <= 5) {
+				int seconds_to_wait = std::pow(2, info->iteration) * 3;
+				info->iteration++;
+				BOOST_LOG_TRIVIAL(info) << "Connection refused, retrying in " << seconds_to_wait << " seconds.";
+				
+				info->retry_timer.expires_from_now(boost::posix_time::seconds(seconds_to_wait));
+				
+				info->retry_timer.async_wait([&socket, info, on_connect](boost::system::error_code const& ec){
+					if(ec) {
+						BOOST_LOG_TRIVIAL(error) << "Something went wrong with the retry timer: " << ec;
+					} else {
+						async_connect_iteration(socket, info, on_connect);
+					}
+				});
+			} else {
+				BOOST_LOG_TRIVIAL(info) << "Connection was refused 5 times over the course of 189 seconds, moving to next resolved query";
+				info->it++;
+				info->iteration = 0;
+				async_connect_iteration(socket, info, on_connect);
+			}
+		} else if(ec) {
 			BOOST_LOG_TRIVIAL(info) << ec << std::endl;
-			async_connect_iteration(socket, std::next(it), on_connect);
+			info->it++;
+			async_connect_iteration(socket, info, on_connect);
 		} else {
 			on_connect();
 		}
 	};
 	
-	socket.async_connect(*it, handler);
+	socket.async_connect(*(info->it), handler);
 }
 
 void async_connect(tcp::socket& socket, std::string host, std::string next_port, std::function<void()> on_connect)
@@ -53,5 +89,7 @@ void async_connect(tcp::socket& socket, std::string host, std::string next_port,
 	
 	auto it = resolver.resolve(query);
 
-	async_connect_iteration(socket, it, on_connect);
+	std::shared_ptr<IterationInfo> info = std::make_shared<IterationInfo>(0, it, socket.get_io_service());
+
+	async_connect_iteration(socket, info, on_connect);
 }