This demonstrates a speedup in confirmation rate during initial boots… (#3644)

* This change limits confirmation requests by the status of the tcp channel rather than by a fixed number.
* Removing confirm_req_batches_max as it's unused.
* Rename channel::full() to channel::max() to match socket::max()
channel::full() was calling channel::max() instead of socket::full(),
which also exists. So it makes sense for consistency to rename it.

Co-authored-by: Dimitrios Siganos <dimitris@siganos.org>

nano/core_test/confirmation_solicitor.cpp

@@ -39,7 +39,6 @@ TEST (confirmation_solicitor, batches)
 		}
 		// Reached the maximum amount of requests for the channel
 		auto election (std::make_shared<nano::election> (node2, send, nullptr, nullptr, nano::election_behavior::normal));
-		ASSERT_TRUE (solicitor.add (*election));
 		// Broadcasting should be immediate
 		ASSERT_EQ (0, node2.stats.count (nano::stat::type::message, nano::stat::detail::publish, nano::stat::dir::out));
 		ASSERT_FALSE (solicitor.broadcast (*election));

nano/core_test/toml.cpp

@@ -187,7 +187,6 @@ TEST (toml, daemon_config_deserialize_defaults)
 	ASSERT_EQ (conf.node.work_peers, defaults.node.work_peers);
 	ASSERT_EQ (conf.node.work_threads, defaults.node.work_threads);
 	ASSERT_EQ (conf.node.max_queued_requests, defaults.node.max_queued_requests);
-	ASSERT_EQ (conf.node.confirm_req_batches_max, defaults.node.confirm_req_batches_max);
 
 	ASSERT_EQ (conf.node.logging.bulk_pull_logging_value, defaults.node.logging.bulk_pull_logging_value);
 	ASSERT_EQ (conf.node.logging.flush, defaults.node.logging.flush);
@@ -594,7 +593,6 @@ TEST (toml, daemon_config_deserialize_no_defaults)
 	ASSERT_NE (conf.node.work_peers, defaults.node.work_peers);
 	ASSERT_NE (conf.node.work_threads, defaults.node.work_threads);
 	ASSERT_NE (conf.node.max_queued_requests, defaults.node.max_queued_requests);
-	ASSERT_EQ (conf.node.confirm_req_batches_max, defaults.node.confirm_req_batches_max);
 
 	ASSERT_NE (conf.node.logging.bulk_pull_logging_value, defaults.node.logging.bulk_pull_logging_value);
 	ASSERT_NE (conf.node.logging.flush, defaults.node.logging.flush);
@@ -830,21 +828,6 @@ TEST (toml, daemon_config_deserialize_errors)
 		ASSERT_EQ (toml.get_error ().get_message (), "election_hint_weight_percent must be a number between 5 and 50");
 	}
 
-	{
-		std::stringstream ss;
-		ss << R"toml(
-		[node]
-		confirm_req_batches_max = 0
-		)toml";
-
-		nano::tomlconfig toml;
-		toml.read (ss);
-		nano::daemon_config conf;
-		conf.deserialize_toml (toml);
-
-		ASSERT_EQ (toml.get_error ().get_message (), "confirm_req_batches_max must be between 1 and 100");
-	}
-
 	{
 		std::stringstream ss;
 		ss << R"toml(

nano/node/confirmation_solicitor.cpp

@@ -57,7 +57,6 @@ bool nano::confirmation_solicitor::add (nano::election const & election_a)
 	debug_assert (prepared);
 	bool error (true);
 	unsigned count = 0;
-	auto const max_channel_requests (config.confirm_req_batches_max * nano::network::confirm_req_hashes_max);
 	auto const & hash (election_a.status.winner->hash ());
 	for (auto i (representatives_requests.begin ()); i != representatives_requests.end () && count < max_election_requests;)
 	{
@@ -70,7 +69,7 @@ bool nano::confirmation_solicitor::add (nano::election const & election_a)
 		if (!exists || !is_final || different)
 		{
 			auto & request_queue (requests[rep.channel]);
-			if (request_queue.size () < max_channel_requests)
+			if (!rep.channel->max ())
 			{
 				request_queue.emplace_back (election_a.status.winner->hash (), election_a.status.winner->root ());
 				count += different ? 0 : 1;

nano/node/nodeconfig.cpp

@@ -121,7 +121,6 @@ nano::error nano::node_config::serialize_toml (nano::tomlconfig & toml) const
 	toml.put ("max_work_generate_multiplier", max_work_generate_multiplier, "Maximum allowed difficulty multiplier for work generation.\ntype:double,[1..]");
 	toml.put ("frontiers_confirmation", serialize_frontiers_confirmation (frontiers_confirmation), "Mode controlling frontier confirmation rate.\ntype:string,{auto,always,disabled}");
 	toml.put ("max_queued_requests", max_queued_requests, "Limit for number of queued confirmation requests for one channel, after which new requests are dropped until the queue drops below this value.\ntype:uint32");
-	toml.put ("confirm_req_batches_max", confirm_req_batches_max, "Limit for the number of confirmation requests for one channel per request attempt\ntype:uint32");
 	toml.put ("rep_crawler_weight_minimum", rep_crawler_weight_minimum.to_string_dec (), "Rep crawler minimum weight, if this is less than minimum principal weight then this is taken as the minimum weight a rep must have to be tracked. If you want to track all reps set this to 0. If you do not want this to influence anything then set it to max value. This is only useful for debugging or for people who really know what they are doing.\ntype:string,amount,raw");
 
 	auto work_peers_l (toml.create_array ("work_peers", "A list of \"address:port\" entries to identify work peers."));
@@ -370,7 +369,6 @@ nano::error nano::node_config::deserialize_toml (nano::tomlconfig & toml)
 		toml.get<double> ("max_work_generate_multiplier", max_work_generate_multiplier);
 
 		toml.get<uint32_t> ("max_queued_requests", max_queued_requests);
-		toml.get<uint32_t> ("confirm_req_batches_max", confirm_req_batches_max);
 
 		auto rep_crawler_weight_minimum_l (rep_crawler_weight_minimum.to_string_dec ());
 		if (toml.has_key ("rep_crawler_weight_minimum"))
@@ -445,10 +443,6 @@ nano::error nano::node_config::deserialize_toml (nano::tomlconfig & toml)
 		{
 			toml.get_error ().set ("max_pruning_age must be greater than or equal to 5 minutes");
 		}
-		if (confirm_req_batches_max < 1 || confirm_req_batches_max > 100)
-		{
-			toml.get_error ().set ("confirm_req_batches_max must be between 1 and 100");
-		}
 		if (bootstrap_frontier_request_count < 1024)
 		{
 			toml.get_error ().set ("bootstrap_frontier_request_count must be greater than or equal to 1024");

nano/node/nodeconfig.hpp

@@ -97,8 +97,6 @@ public:
 	bool backup_before_upgrade{ false };
 	double max_work_generate_multiplier{ 64. };
 	uint32_t max_queued_requests{ 512 };
-	/** Maximum amount of confirmation requests (batches) to be sent to each channel */
-	uint32_t confirm_req_batches_max{ network_params.network.is_dev_network () ? 1u : 2u };
 	std::chrono::seconds max_pruning_age{ !network_params.network.is_beta_network () ? std::chrono::seconds (24 * 60 * 60) : std::chrono::seconds (5 * 60) }; // 1 day; 5 minutes for beta network
 	uint64_t max_pruning_depth{ 0 };
 	nano::rocksdb_config rocksdb_config;

nano/node/transport/tcp.hpp

@@ -68,6 +68,16 @@ namespace transport
 			return nano::transport::transport_type::tcp;
 		}
 
+		virtual bool max () override
+		{
+			bool result = true;
+			if (auto socket_l = socket.lock ())
+			{
+				result = socket_l->max ();
+			}
+			return result;
+		}
+
 	private:
 		nano::tcp_endpoint endpoint{ boost::asio::ip::address_v6::any (), 0 };
 	};

nano/node/transport/transport.hpp

@@ -58,6 +58,10 @@ namespace transport
 		virtual nano::endpoint get_endpoint () const = 0;
 		virtual nano::tcp_endpoint get_tcp_endpoint () const = 0;
 		virtual nano::transport::transport_type get_type () const = 0;
+		virtual bool max ()
+		{
+			return false;
+		}
 
 		std::chrono::steady_clock::time_point get_last_bootstrap_attempt () const
 		{