Ensure jsonrpc threading settings are sane

parity/cli/mod.rs

@@ -506,18 +506,18 @@ usage! {
 			"--jsonrpc-hosts=[HOSTS]",
 			"List of allowed Host header values. This option will validate the Host header sent by the browser, it is additional security against some attack vectors. Special options: \"all\", \"none\",.",
 
-			ARG arg_jsonrpc_threads: (usize) = 4usize, or |c: &Config| c.rpc.as_ref()?.processing_threads,
+			ARG arg_jsonrpc_threads: (Option<usize>) = Some(4), or |c: &Config| c.rpc.as_ref()?.processing_threads,
 			"--jsonrpc-threads=[THREADS]",
 			"Turn on additional processing threads for JSON-RPC servers (all transports). Setting this to a non-zero value allows parallel execution of cpu-heavy queries.",
 
+			ARG arg_jsonrpc_server_threads: (Option<usize>) = Some(4), or |c: &Config| c.rpc.as_ref()?.server_threads,
+			"--jsonrpc-server-threads=[THREADS]",
+			"Enables multiple threads handling incoming connections for HTTP JSON-RPC server.",
+
 			ARG arg_jsonrpc_cors: (String) = "none", or |c: &Config| c.rpc.as_ref()?.cors.as_ref().map(|vec| vec.join(",")),
 			"--jsonrpc-cors=[URL]",
 			"Specify CORS header for HTTP JSON-RPC API responses. Special options: \"all\", \"none\".",
 
-			ARG arg_jsonrpc_server_threads: (Option<usize>) = None, or |c: &Config| c.rpc.as_ref()?.server_threads,
-			"--jsonrpc-server-threads=[NUM]",
-			"Enables multiple threads handling incoming connections for HTTP JSON-RPC server.",
-
 			ARG arg_jsonrpc_max_payload: (Option<usize>) = None, or |c: &Config| c.rpc.as_ref()?.max_payload,
 			"--jsonrpc-max-payload=[MB]",
 			"Specify maximum size for HTTP JSON-RPC requests in megabytes.",
@@ -1816,8 +1816,8 @@ mod tests {
 			arg_jsonrpc_cors: "null".into(),
 			arg_jsonrpc_apis: "web3,eth,net,parity,traces,rpc,secretstore".into(),
 			arg_jsonrpc_hosts: "none".into(),
-			arg_jsonrpc_server_threads: None,
-			arg_jsonrpc_threads: 4,
+			arg_jsonrpc_server_threads: Some(4),
+			arg_jsonrpc_threads: Some(4),
 			arg_jsonrpc_max_payload: None,
 			arg_poll_lifetime: 60u32,
 			flag_jsonrpc_allow_missing_blocks: false,
@@ -2095,8 +2095,8 @@ mod tests {
 				cors: None,
 				apis: None,
 				hosts: None,
-				server_threads: None,
-				processing_threads: None,
+				server_threads: Some(13),
+				processing_threads: Some(14),
 				max_payload: None,
 				keep_alive: None,
 				experimental_rpcs: None,

parity/cli/tests/config.toml

@@ -31,6 +31,8 @@ origins = ["none"]
 [rpc]
 disable = true
 port = 8180
+server_threads = 13
+processing_threads = 14
 
 [ipc]
 apis = ["rpc", "eth"]

parity/configuration.rs

@@ -367,49 +367,49 @@ impl Configuration {
 			let (private_provider_conf, private_enc_conf, private_tx_enabled) = self.private_provider_config()?;
 
 			let run_cmd = RunCmd {
-				cache_config: cache_config,
-				dirs: dirs,
-				spec: spec,
-				pruning: pruning,
-				pruning_history: pruning_history,
+				cache_config,
+				dirs,
+				spec,
+				pruning,
+				pruning_history,
 				pruning_memory: self.args.arg_pruning_memory,
-				daemon: daemon,
+				daemon,
 				logger_config: logger_config.clone(),
 				miner_options: self.miner_options()?,
 				gas_price_percentile: self.args.arg_gas_price_percentile,
 				poll_lifetime: self.args.arg_poll_lifetime,
-				ws_conf: ws_conf,
-				snapshot_conf: snapshot_conf,
-				http_conf: http_conf,
-				ipc_conf: ipc_conf,
-				net_conf: net_conf,
-				network_id: network_id,
+				ws_conf,
+				snapshot_conf,
+				http_conf,
+				ipc_conf,
+				net_conf,
+				network_id,
 				acc_conf: self.accounts_config()?,
 				gas_pricer_conf: self.gas_pricer_config()?,
 				miner_extras: self.miner_extras()?,
 				stratum: self.stratum_options()?,
-				update_policy: update_policy,
+				update_policy,
 				allow_missing_blocks: self.args.flag_jsonrpc_allow_missing_blocks,
-				mode: mode,
-				tracing: tracing,
-				fat_db: fat_db,
-				compaction: compaction,
-				vm_type: vm_type,
-				warp_sync: warp_sync,
+				mode,
+				tracing,
+				fat_db,
+				compaction,
+				vm_type,
+				warp_sync,
 				warp_barrier: self.args.arg_warp_barrier,
-				geth_compatibility: geth_compatibility,
+				geth_compatibility,
 				experimental_rpcs,
 				net_settings: self.network_settings()?,
-				ipfs_conf: ipfs_conf,
-				secretstore_conf: secretstore_conf,
-				private_provider_conf: private_provider_conf,
+				ipfs_conf,
+				secretstore_conf,
+				private_provider_conf,
 				private_encryptor_conf: private_enc_conf,
 				private_tx_enabled,
 				name: self.args.arg_identity,
 				custom_bootnodes: self.args.arg_bootnodes.is_some(),
 				check_seal: !self.args.flag_no_seal_check,
 				download_old_blocks: !self.args.flag_no_ancient_blocks,
-				verifier_settings: verifier_settings,
+				verifier_settings,
 				serve_light: !self.args.flag_no_serve_light,
 				light: self.args.flag_light,
 				no_persistent_txqueue: self.args.flag_no_persistent_txqueue,
@@ -885,24 +885,23 @@ impl Configuration {
 	}
 
 	fn http_config(&self) -> Result<HttpConfiguration, String> {
-		let conf = HttpConfiguration {
-			enabled: self.rpc_enabled(),
-			interface: self.rpc_interface(),
-			port: self.args.arg_ports_shift + self.args.arg_rpcport.unwrap_or(self.args.arg_jsonrpc_port),
-			apis: self.rpc_apis().parse()?,
-			hosts: self.rpc_hosts(),
-			cors: self.rpc_cors(),
-			server_threads: match self.args.arg_jsonrpc_server_threads {
-				Some(threads) if threads > 0 => threads,
-				_ => 1,
-			},
-			processing_threads: self.args.arg_jsonrpc_threads,
-			max_payload: match self.args.arg_jsonrpc_max_payload {
-				Some(max) if max > 0 => max as usize,
-				_ => 5usize,
-			},
-			keep_alive: !self.args.flag_jsonrpc_no_keep_alive,
-		};
+		let mut conf = HttpConfiguration::default();
+		conf.enabled = self.rpc_enabled();
+		conf.interface = self.rpc_interface();
+		conf.port = self.args.arg_ports_shift + self.args.arg_rpcport.unwrap_or(self.args.arg_jsonrpc_port);
+		conf.apis = self.rpc_apis().parse()?;
+		conf.hosts = self.rpc_hosts();
+		conf.cors = self.rpc_cors();
+		if let Some(threads) = self.args.arg_jsonrpc_server_threads {
+			conf.server_threads = std::cmp::max(1, threads);
+		}
+		if let Some(threads) = self.args.arg_jsonrpc_threads {
+			conf.processing_threads = std::cmp::max(1, threads);
+		}
+		if let Some(max_payload) = self.args.arg_jsonrpc_max_payload {
+			conf.max_payload = std::cmp::max(1, max_payload);
+		}
+		conf.keep_alive = !self.args.flag_jsonrpc_no_keep_alive;
 
 		Ok(conf)
 	}
@@ -1626,6 +1625,31 @@ mod tests {
 		assert_eq!(conf3.rpc_hosts(), Some(vec!["parity.io".into(), "something.io".into()]));
 	}
 
+	#[test]
+	fn ensures_sane_http_settings() {
+		// given incorrect settings
+		let conf = parse(&["parity",
+			"--jsonrpc-server-threads=0",
+			"--jsonrpc-threads=0",
+			"--jsonrpc-max-payload=0",
+		]);
+
+		// then things are adjusted to Just Work.
+		let http_conf = conf.http_config().unwrap();
+		assert_eq!(http_conf.server_threads, 1);
+		assert_eq!(http_conf.processing_threads, 1);
+		assert_eq!(http_conf.max_payload, 1);
+	}
+
+	#[test]
+	fn jsonrpc_threading_defaults() {
+		let conf = parse(&["parity"]);
+		let http_conf = conf.http_config().unwrap();
+		assert_eq!(http_conf.server_threads, 4);
+		assert_eq!(http_conf.processing_threads, 4);
+		assert_eq!(http_conf.max_payload, 5);
+	}
+
 	#[test]
 	fn should_parse_ipfs_hosts() {
 		// given

parity/lib.rs

@@ -193,9 +193,12 @@ pub enum ExecutionAction {
 fn execute<Cr, Rr>(
 	command: Execute,
 	logger: Arc<RotatingLogger>,
-	on_client_rq: Cr, on_updater_rq: Rr) -> Result<ExecutionAction, String>
-	where Cr: Fn(String) + 'static + Send,
-		  Rr: Fn() + 'static + Send
+	on_client_rq: Cr,
+	on_updater_rq: Rr
+) -> Result<ExecutionAction, String>
+	where
+		Cr: Fn(String) + 'static + Send,
+		Rr: Fn() + 'static + Send
 {
 	#[cfg(feature = "deadlock_detection")]
 	run_deadlock_detection_thread();

parity/rpc.rs

@@ -35,15 +35,26 @@ pub const DAPPS_DOMAIN: &'static str = "web3.site";
 
 #[derive(Debug, Clone, PartialEq)]
 pub struct HttpConfiguration {
+	/// Is RPC over HTTP enabled (default is true)?
 	pub enabled: bool,
+	/// The IP of the network interface used (default is 127.0.0.1).
 	pub interface: String,
+	/// The network port (default is 8545).
 	pub port: u16,
+	/// The categories of RPC calls enabled.
 	pub apis: ApiSet,
+	/// CORS headers
 	pub cors: Option<Vec<String>>,
+	/// Specify a list of valid hosts we accept requests from.
 	pub hosts: Option<Vec<String>>,
+	/// Number of threads to use to handle incoming requests (default is 4).
 	pub server_threads: usize,
+	/// Number of threads to use to process HTTP requests (default is 4).
 	pub processing_threads: usize,
+	/// Sets the maximum size of a request body in megabytes (default is 5 MiB).
 	pub max_payload: usize,
+	/// Use keepalive messages on the underlying socket: SO_KEEPALIVE as well as the TCP_KEEPALIVE
+	/// or TCP_KEEPIDLE options depending on your platform (default is true).
 	pub keep_alive: bool,
 }
 
@@ -56,7 +67,7 @@ impl Default for HttpConfiguration {
 			apis: ApiSet::UnsafeContext,
 			cors: Some(vec![]),
 			hosts: Some(vec![]),
-			server_threads: 1,
+			server_threads: 4,
 			processing_threads: 4,
 			max_payload: 5,
 			keep_alive: true,

parity/run.rs

@@ -361,9 +361,14 @@ fn execute_light_impl<Cr>(cmd: RunCmd, logger: Arc<RotatingLogger>, on_client_rq
 	})
 }
 
-fn execute_impl<Cr, Rr>(cmd: RunCmd, logger: Arc<RotatingLogger>, on_client_rq: Cr,
-						on_updater_rq: Rr) -> Result<RunningClient, String>
-	where Cr: Fn(String) + 'static + Send,
+fn execute_impl<Cr, Rr>(
+	cmd: RunCmd,
+	logger: Arc<RotatingLogger>,
+	on_client_rq: Cr,
+	on_updater_rq: Rr
+) -> Result<RunningClient, String>
+	where
+		Cr: Fn(String) + 'static + Send,
 		Rr: Fn() + 'static + Send
 {
 	// load spec
@@ -910,9 +915,14 @@ impl RunningClient {
 /// `on_updater_rq` is the action to perform when the updater has a new binary to execute.
 ///
 /// On error, returns what to print on stderr.
-pub fn execute<Cr, Rr>(cmd: RunCmd, logger: Arc<RotatingLogger>,
-						on_client_rq: Cr, on_updater_rq: Rr) -> Result<RunningClient, String>
-	where Cr: Fn(String) + 'static + Send,
+pub fn execute<Cr, Rr>(
+	cmd: RunCmd,
+	logger: Arc<RotatingLogger>,
+	on_client_rq: Cr,
+	on_updater_rq: Rr
+) -> Result<RunningClient, String>
+	where
+		Cr: Fn(String) + 'static + Send,
 		Rr: Fn() + 'static + Send
 {
 	if cmd.light {