Expose health status over RPC

Cargo.toml

@@ -43,6 +43,7 @@ ethcore-logger = { path = "logger" }
 ethcore-stratum = { path = "stratum" }
 ethcore-network = { path = "util/network" }
 ethkey = { path = "ethkey" }
+node-health = { path = "dapps/node-health" }
 rlp = { path = "util/rlp" }
 rpc-cli = { path = "rpc_cli" }
 parity-hash-fetch = { path = "hash-fetch" }
@@ -110,4 +111,4 @@ lto = false
 panic = "abort"
 
 [workspace]
-members = ["ethstore/cli", "ethkey/cli", "evmbin", "whisper", "chainspec"]
+members = ["ethstore/cli", "ethkey/cli", "evmbin", "whisper", "chainspec", "dapps/node-health"]

dapps/Cargo.toml

@@ -9,15 +9,12 @@ authors = ["Parity Technologies <admin@parity.io>"]
 
 [dependencies]
 base32 = "0.3"
-env_logger = "0.4"
 futures = "0.1"
-futures-cpupool = "0.1"
 linked-hash-map = "0.3"
 log = "0.3"
 parity-dapps-glue = "1.7"
 mime = "0.2"
 mime_guess = "1.6.1"
-ntp = "0.2.0"
 rand = "0.3"
 rustc-hex = "1.0"
 serde = "1.0"
@@ -31,15 +28,19 @@ zip = { version = "0.1", default-features = false }
 jsonrpc-core = { git = "https://github.com/paritytech/jsonrpc.git", branch = "parity-1.7" }
 jsonrpc-http-server = { git = "https://github.com/paritytech/jsonrpc.git", branch = "parity-1.7" }
 
-ethcore-devtools = { path = "../devtools" }
 ethcore-util = { path = "../util" }
 fetch = { path = "../util/fetch" }
+node-health = { path = "./node-health" }
 parity-hash-fetch = { path = "../hash-fetch" }
 parity-reactor = { path = "../util/reactor" }
 parity-ui = { path = "./ui" }
 
 clippy = { version = "0.0.103", optional = true}
 
+[dev-dependencies]
+env_logger = "0.4"
+ethcore-devtools = { path = "../devtools" }
+
 [features]
 dev = ["clippy", "ethcore-util/dev"]
 

dapps/node-health/Cargo.toml

@@ -0,0 +1,18 @@
+[package]
+name = "node-health"
+description = "Node's health status"
+version = "0.1.0"
+license = "GPL-3.0"
+authors = ["Parity Technologies <admin@parity.io>"]
+
+[dependencies]
+futures = "0.1"
+futures-cpupool = "0.1"
+log = "0.3"
+ntp = "0.2.0"
+parking_lot = "0.4"
+serde = "1.0"
+serde_derive = "1.0"
+time = "0.1.35"
+
+parity-reactor = { path = "../../util/reactor" }

dapps/node-health/src/health.rs

@@ -0,0 +1,122 @@
+// Copyright 2015-2017 Parity Technologies (UK) Ltd.
+// This file is part of Parity.
+
+// Parity is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+
+// Parity is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+
+// You should have received a copy of the GNU General Public License
+// along with Parity.  If not, see <http://www.gnu.org/licenses/>.
+
+//! Reporting node's health.
+
+use std::sync::Arc;
+use std::time;
+use futures::{Future, BoxFuture};
+use futures::sync::oneshot;
+use types::{HealthInfo, HealthStatus, Health};
+use time::{TimeChecker, MAX_DRIFT};
+use parity_reactor::Remote;
+use parking_lot::Mutex;
+use {SyncStatus};
+
+const TIMEOUT_SECS: u64 = 5;
+const PROOF: &str = "Only one closure is invoked.";
+
+/// A struct enabling you to query for node's health.
+#[derive(Debug, Clone)]
+pub struct NodeHealth {
+	sync_status: Arc<SyncStatus>,
+	time: TimeChecker,
+	remote: Remote,
+}
+
+impl NodeHealth {
+	/// Creates new `NodeHealth`.
+	pub fn new(sync_status: Arc<SyncStatus>, time: TimeChecker, remote: Remote) -> Self {
+		NodeHealth { sync_status, time, remote, }
+	}
+
+	/// Query latest health report.
+	pub fn health(&self) -> BoxFuture<Health, ()> {
+		trace!(target: "dapps", "Checking node health.");
+		// Check timediff
+		let sync_status = self.sync_status.clone();
+		let time = self.time.time_drift();
+		let (tx, rx) = oneshot::channel();
+		let tx = Arc::new(Mutex::new(Some(tx)));
+		let tx2 = tx.clone();
+		self.remote.spawn_with_timeout(
+			move || time.then(move |result| {
+				let _ = tx.lock().take().expect(PROOF).send(Ok(result));
+				Ok(())
+			}),
+			time::Duration::from_secs(TIMEOUT_SECS),
+			move || {
+				let _ = tx2.lock().take().expect(PROOF).send(Err(()));
+			},
+		);
+
+		rx.map_err(|err| {
+			warn!(target: "dapps", "Health request cancelled: {:?}", err);
+		}).and_then(move |time| {
+			// Check peers
+			let peers = {
+				let (connected, max) = sync_status.peers();
+				let (status, message) = match connected {
+					0 => {
+						(HealthStatus::Bad, "You are not connected to any peers. There is most likely some network issue. Fix connectivity.".into())
+					},
+					1 => (HealthStatus::NeedsAttention, "You are connected to only one peer. Your node might not be reliable. Check your network connection.".into()),
+					_ => (HealthStatus::Ok, "".into()),
+				};
+				HealthInfo { status, message, details: (connected, max) }
+			};
+
+			// Check sync
+			let sync = {
+				let is_syncing = sync_status.is_major_importing();
+				let (status, message) = if is_syncing {
+					(HealthStatus::NeedsAttention, "Your node is still syncing, the values you see might be outdated. Wait until it's fully synced.".into())
+				} else {
+					(HealthStatus::Ok, "".into())
+				};
+				HealthInfo { status, message, details: is_syncing }
+			};
+
+			// Check time
+			let time = {
+				let (status, message, details) = match time {
+					Ok(Ok(diff)) if diff < MAX_DRIFT && diff > -MAX_DRIFT => {
+						(HealthStatus::Ok, "".into(), diff)
+					},
+					Ok(Ok(diff)) => {
+						(HealthStatus::Bad, format!(
+							"Your clock is not in sync. Detected difference is too big for the protocol to work: {}ms. Synchronize your clock.",
+							diff,
+						), diff)
+					},
+					Ok(Err(err)) => {
+						(HealthStatus::NeedsAttention, format!(
+							"Unable to reach time API: {}. Make sure that your clock is synchronized.",
+							err,
+						), 0)
+					},
+					Err(_) => {
+						(HealthStatus::NeedsAttention, "Time API request timed out. Make sure that the clock is synchronized.".into(), 0)
+					},
+				};
+
+				HealthInfo { status, message, details, }
+			};
+
+			Ok(Health { peers, sync, time})
+		}).boxed()
+	}
+}

dapps/node-health/src/lib.rs

@@ -0,0 +1,49 @@
+// Copyright 2015-2017 Parity Technologies (UK) Ltd.
+// This file is part of Parity.
+
+// Parity is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+
+// Parity is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+
+// You should have received a copy of the GNU General Public License
+// along with Parity.  If not, see <http://www.gnu.org/licenses/>.
+
+//! Node Health status reporting.
+
+#![warn(missing_docs)]
+
+extern crate futures;
+extern crate futures_cpupool;
+extern crate ntp;
+extern crate time as time_crate;
+extern crate parity_reactor;
+extern crate parking_lot;
+
+#[macro_use]
+extern crate log;
+#[macro_use]
+extern crate serde_derive;
+
+mod health;
+mod time;
+mod types;
+
+pub use futures_cpupool::CpuPool;
+pub use health::NodeHealth;
+pub use types::{Health, HealthInfo, HealthStatus};
+pub use time::{TimeChecker, Error};
+
+/// Indicates sync status
+pub trait SyncStatus: ::std::fmt::Debug + Send + Sync {
+	/// Returns true if there is a major sync happening.
+	fn is_major_importing(&self) -> bool;
+
+	/// Returns number of connected and ideal peers.
+	fn peers(&self) -> (usize, usize);
+}

dapps/src/api/time.rs → dapps/node-health/src/time.rs

@@ -41,8 +41,8 @@ use futures::{self, Future, BoxFuture};
 use futures::future::{self, IntoFuture};
 use futures_cpupool::{CpuPool, CpuFuture};
 use ntp;
-use time::{Duration, Timespec};
-use util::RwLock;
+use parking_lot::RwLock;
+use time_crate::{Duration, Timespec};
 
 /// Time checker error.
 #[derive(Debug, Clone, PartialEq)]
@@ -164,7 +164,7 @@ impl Ntp for SimpleNtp {
 
 				match ntp::request(&server.address) {
 					Ok(packet) => {
-						let dest_time = ::time::now_utc().to_timespec();
+						let dest_time = ::time_crate::now_utc().to_timespec();
 						let orig_time = Timespec::from(packet.orig_time);
 						let recv_time = Timespec::from(packet.recv_time);
 						let transmit_time = Timespec::from(packet.transmit_time);

dapps/node-health/src/types.rs

@@ -0,0 +1,57 @@
+// Copyright 2015-2017 Parity Technologies (UK) Ltd.
+// This file is part of Parity.
+
+// Parity is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+
+// Parity is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+
+// You should have received a copy of the GNU General Public License
+// along with Parity.  If not, see <http://www.gnu.org/licenses/>.
+
+//! Base health types.
+
+/// Health API endpoint status.
+#[derive(Debug, PartialEq, Serialize)]
+pub enum HealthStatus {
+	/// Everything's OK.
+	#[serde(rename = "ok")]
+	Ok,
+	/// Node health need attention
+	/// (the issue is not critical, but may need investigation)
+	#[serde(rename = "needsAttention")]
+	NeedsAttention,
+	/// There is something bad detected with the node.
+	#[serde(rename = "bad")]
+	Bad
+}
+
+/// Represents a single check in node health.
+/// Cointains the status of that check and apropriate message and details.
+#[derive(Debug, PartialEq, Serialize)]
+#[serde(deny_unknown_fields)]
+pub struct HealthInfo<T> {
+	/// Check status.
+	pub status: HealthStatus,
+	/// Human-readable message.
+	pub message: String,
+	/// Technical details of the check.
+	pub details: T,
+}
+
+/// Node Health status.
+#[derive(Debug, PartialEq, Serialize)]
+#[serde(deny_unknown_fields)]
+pub struct Health {
+	/// Status of peers.
+	pub peers: HealthInfo<(usize, usize)>,
+	/// Sync status.
+	pub sync: HealthInfo<bool>,
+	/// Time diff info.
+	pub time: HealthInfo<i64>,
+}