use std::collections::HashMap; use std::fmt::Write as FmtWrite; use std::io::{Read, Write}; use std::net::{IpAddr, SocketAddr}; use std::path::PathBuf; use std::sync::atomic::{AtomicUsize, Ordering}; use std::sync::Arc; use std::time::Duration; use futures::future::join_all; use futures::select; use futures_util::future::*; use serde::{Deserialize, Serialize}; use tokio::sync::watch; use tokio::sync::Mutex; use garage_util::background::BackgroundRunner; use garage_util::data::*; use garage_util::error::Error; use garage_util::persister::Persister; use garage_util::time::*; use crate::consul::get_consul_nodes; use crate::ring::*; use crate::rpc_client::*; use crate::rpc_server::*; const PING_INTERVAL: Duration = Duration::from_secs(10); const DISCOVERY_INTERVAL: Duration = Duration::from_secs(60); const PING_TIMEOUT: Duration = Duration::from_secs(2); const MAX_FAILURES_BEFORE_CONSIDERED_DOWN: usize = 5; pub const MEMBERSHIP_RPC_PATH: &str = "_membership"; #[derive(Debug, Serialize, Deserialize)] pub enum Message { Ok, Ping(PingMessage), PullStatus, PullConfig, AdvertiseNodesUp(Vec), AdvertiseConfig(NetworkConfig), } impl RpcMessage for Message {} #[derive(Debug, Serialize, Deserialize)] pub struct PingMessage { id: UUID, rpc_port: u16, status_hash: Hash, config_version: u64, state_info: StateInfo, } #[derive(Clone, Debug, Serialize, Deserialize)] pub struct AdvertisedNode { pub id: UUID, pub addr: SocketAddr, pub is_up: bool, pub last_seen: u64, pub state_info: StateInfo, } pub struct System { pub id: UUID, persist_config: Persister, persist_status: Persister>, rpc_local_port: u16, state_info: StateInfo, rpc_http_client: Arc, rpc_client: Arc>, pub(crate) status: watch::Receiver>, pub ring: watch::Receiver>, update_lock: Mutex, pub background: Arc, } struct Updaters { update_status: watch::Sender>, update_ring: watch::Sender>, } #[derive(Debug, Clone)] pub struct Status { pub nodes: HashMap>, pub hash: Hash, } #[derive(Debug)] pub struct StatusEntry { pub addr: SocketAddr, pub last_seen: u64, pub num_failures: AtomicUsize, pub state_info: StateInfo, } impl StatusEntry { pub fn is_up(&self) -> bool { self.num_failures.load(Ordering::SeqCst) < MAX_FAILURES_BEFORE_CONSIDERED_DOWN } } #[derive(Debug, Clone, Serialize, Deserialize)] pub struct StateInfo { pub hostname: String, } impl Status { fn handle_ping(&mut self, ip: IpAddr, info: &PingMessage) -> bool { let addr = SocketAddr::new(ip, info.rpc_port); let old_status = self.nodes.insert( info.id, Arc::new(StatusEntry { addr, last_seen: now_msec(), num_failures: AtomicUsize::from(0), state_info: info.state_info.clone(), }), ); match old_status { None => { info!("Newly pingable node: {}", hex::encode(&info.id)); true } Some(x) => x.addr != addr, } } fn recalculate_hash(&mut self) { let mut nodes = self.nodes.iter().collect::>(); nodes.sort_unstable_by_key(|(id, _status)| *id); let mut nodes_txt = String::new(); debug!("Current set of pingable nodes: --"); for (id, status) in nodes { debug!("{} {}", hex::encode(&id), status.addr); writeln!(&mut nodes_txt, "{} {}", hex::encode(&id), status.addr).unwrap(); } debug!("END --"); self.hash = blake2sum(nodes_txt.as_bytes()); } fn to_serializable_membership(&self, system: &System) -> Vec { let mut mem = vec![]; for (node, status) in self.nodes.iter() { let state_info = if *node == system.id { system.state_info.clone() } else { status.state_info.clone() }; mem.push(AdvertisedNode { id: *node, addr: status.addr, is_up: status.is_up(), last_seen: status.last_seen, state_info, }); } mem } } fn gen_node_id(metadata_dir: &PathBuf) -> Result { let mut id_file = metadata_dir.clone(); id_file.push("node_id"); if id_file.as_path().exists() { let mut f = std::fs::File::open(id_file.as_path())?; let mut d = vec![]; f.read_to_end(&mut d)?; if d.len() != 32 { return Err(Error::Message(format!("Corrupt node_id file"))); } let mut id = [0u8; 32]; id.copy_from_slice(&d[..]); Ok(id.into()) } else { let id = gen_uuid(); let mut f = std::fs::File::create(id_file.as_path())?; f.write_all(id.as_slice())?; Ok(id) } } impl System { pub fn new( metadata_dir: PathBuf, rpc_http_client: Arc, background: Arc, rpc_server: &mut RpcServer, ) -> Arc { let id = gen_node_id(&metadata_dir).expect("Unable to read or generate node ID"); info!("Node ID: {}", hex::encode(&id)); let persist_config = Persister::new(&metadata_dir, "network_config"); let persist_status = Persister::new(&metadata_dir, "peer_info"); let net_config = match persist_config.load() { Ok(x) => x, Err(e) => { info!( "No valid previous network configuration stored ({}), starting fresh.", e ); NetworkConfig::new() } }; let mut status = Status { nodes: HashMap::new(), hash: Hash::default(), }; status.recalculate_hash(); let (update_status, status) = watch::channel(Arc::new(status)); let state_info = StateInfo { hostname: gethostname::gethostname() .into_string() .unwrap_or("".to_string()), }; let ring = Ring::new(net_config); let (update_ring, ring) = watch::channel(Arc::new(ring)); let rpc_path = MEMBERSHIP_RPC_PATH.to_string(); let rpc_client = RpcClient::new( RpcAddrClient::::new(rpc_http_client.clone(), rpc_path.clone()), background.clone(), status.clone(), ); let sys = Arc::new(System { id, persist_config, persist_status, rpc_local_port: rpc_server.bind_addr.port(), state_info, rpc_http_client, rpc_client, status, ring, update_lock: Mutex::new(Updaters { update_status, update_ring, }), background, }); sys.clone().register_handler(rpc_server, rpc_path); sys } fn register_handler(self: Arc, rpc_server: &mut RpcServer, path: String) { rpc_server.add_handler::(path, move |msg, addr| { let self2 = self.clone(); async move { match msg { Message::Ping(ping) => self2.handle_ping(&addr, &ping).await, Message::PullStatus => self2.handle_pull_status(), Message::PullConfig => self2.handle_pull_config(), Message::AdvertiseNodesUp(adv) => self2.handle_advertise_nodes_up(&adv).await, Message::AdvertiseConfig(adv) => self2.handle_advertise_config(&adv).await, _ => Err(Error::BadRPC(format!("Unexpected RPC message"))), } } }); } pub fn rpc_client(self: &Arc, path: &str) -> Arc> { RpcClient::new( RpcAddrClient::new(self.rpc_http_client.clone(), path.to_string()), self.background.clone(), self.status.clone(), ) } async fn save_network_config(self: Arc) -> Result<(), Error> { let ring = self.ring.borrow().clone(); self.persist_config .save_async(&ring.config) .await .expect("Cannot save current cluster configuration"); Ok(()) } fn make_ping(&self) -> Message { let status = self.status.borrow().clone(); let ring = self.ring.borrow().clone(); Message::Ping(PingMessage { id: self.id, rpc_port: self.rpc_local_port, status_hash: status.hash, config_version: ring.config.version, state_info: self.state_info.clone(), }) } async fn broadcast(self: Arc, msg: Message, timeout: Duration) { let status = self.status.borrow().clone(); let to = status .nodes .keys() .filter(|x| **x != self.id) .cloned() .collect::>(); self.rpc_client.call_many(&to[..], msg, timeout).await; } pub async fn bootstrap( self: Arc, peers: Vec, consul_host: Option, consul_service_name: Option, ) { let self2 = self.clone(); self.background .spawn_worker(format!("discovery loop"), |stop_signal| { self2.discovery_loop(peers, stop_signal) }); let self2 = self.clone(); self.background .spawn_worker(format!("ping loop"), |stop_signal| { self2.ping_loop(stop_signal) }); if let (Some(consul_host), Some(consul_service_name)) = (consul_host, consul_service_name) { let self2 = self.clone(); self.background .spawn_worker(format!("Consul loop"), |stop_signal| { self2.consul_loop(stop_signal, consul_host, consul_service_name) }); } } async fn ping_nodes(self: Arc, peers: Vec<(SocketAddr, Option)>) { let ping_msg = self.make_ping(); let ping_resps = join_all(peers.iter().map(|(addr, id_option)| { let sys = self.clone(); let ping_msg_ref = &ping_msg; async move { ( id_option, addr, sys.rpc_client .by_addr() .call(&addr, ping_msg_ref, PING_TIMEOUT) .await, ) } })) .await; let update_locked = self.update_lock.lock().await; let mut status: Status = self.status.borrow().as_ref().clone(); let ring = self.ring.borrow().clone(); let mut has_changes = false; let mut to_advertise = vec![]; for (id_option, addr, ping_resp) in ping_resps { if let Ok(Ok(Message::Ping(info))) = ping_resp { let is_new = status.handle_ping(addr.ip(), &info); if is_new { has_changes = true; to_advertise.push(AdvertisedNode { id: info.id, addr: *addr, is_up: true, last_seen: now_msec(), state_info: info.state_info.clone(), }); } if is_new || status.hash != info.status_hash { self.background .spawn_cancellable(self.clone().pull_status(info.id).map(Ok)); } if is_new || ring.config.version < info.config_version { self.background .spawn_cancellable(self.clone().pull_config(info.id).map(Ok)); } } else if let Some(id) = id_option { if let Some(st) = status.nodes.get_mut(id) { st.num_failures.fetch_add(1, Ordering::SeqCst); if !st.is_up() { warn!("Node {:?} seems to be down.", id); if !ring.config.members.contains_key(id) { info!("Removing node {:?} from status (not in config and not responding to pings anymore)", id); drop(st); status.nodes.remove(&id); has_changes = true; } } } } } if has_changes { status.recalculate_hash(); } self.update_status(&update_locked, status).await; drop(update_locked); if to_advertise.len() > 0 { self.broadcast(Message::AdvertiseNodesUp(to_advertise), PING_TIMEOUT) .await; } } async fn handle_ping( self: Arc, from: &SocketAddr, ping: &PingMessage, ) -> Result { let update_locked = self.update_lock.lock().await; let mut status: Status = self.status.borrow().as_ref().clone(); let is_new = status.handle_ping(from.ip(), ping); if is_new { status.recalculate_hash(); } let status_hash = status.hash; let config_version = self.ring.borrow().config.version; self.update_status(&update_locked, status).await; drop(update_locked); if is_new || status_hash != ping.status_hash { self.background .spawn_cancellable(self.clone().pull_status(ping.id).map(Ok)); } if is_new || config_version < ping.config_version { self.background .spawn_cancellable(self.clone().pull_config(ping.id).map(Ok)); } Ok(self.make_ping()) } fn handle_pull_status(&self) -> Result { Ok(Message::AdvertiseNodesUp( self.status.borrow().to_serializable_membership(self), )) } fn handle_pull_config(&self) -> Result { let ring = self.ring.borrow().clone(); Ok(Message::AdvertiseConfig(ring.config.clone())) } async fn handle_advertise_nodes_up( self: Arc, adv: &[AdvertisedNode], ) -> Result { let mut to_ping = vec![]; let update_lock = self.update_lock.lock().await; let mut status: Status = self.status.borrow().as_ref().clone(); let mut has_changed = false; for node in adv.iter() { if node.id == self.id { // learn our own ip address let self_addr = SocketAddr::new(node.addr.ip(), self.rpc_local_port); let old_self = status.nodes.insert( node.id, Arc::new(StatusEntry { addr: self_addr, last_seen: now_msec(), num_failures: AtomicUsize::from(0), state_info: self.state_info.clone(), }), ); has_changed = match old_self { None => true, Some(x) => x.addr != self_addr, }; } else { let ping_them = match status.nodes.get(&node.id) { // Case 1: new node None => true, // Case 2: the node might have changed address Some(our_node) => node.is_up && !our_node.is_up() && our_node.addr != node.addr, }; if ping_them { to_ping.push((node.addr, Some(node.id))); } } } if has_changed { status.recalculate_hash(); } self.update_status(&update_lock, status).await; drop(update_lock); if to_ping.len() > 0 { self.background .spawn_cancellable(self.clone().ping_nodes(to_ping).map(Ok)); } Ok(Message::Ok) } async fn handle_advertise_config( self: Arc, adv: &NetworkConfig, ) -> Result { let update_lock = self.update_lock.lock().await; let ring: Arc = self.ring.borrow().clone(); if adv.version > ring.config.version { let ring = Ring::new(adv.clone()); update_lock.update_ring.send(Arc::new(ring))?; drop(update_lock); self.background.spawn_cancellable( self.clone() .broadcast(Message::AdvertiseConfig(adv.clone()), PING_TIMEOUT) .map(Ok), ); self.background.spawn(self.clone().save_network_config()); } Ok(Message::Ok) } async fn ping_loop(self: Arc, mut stop_signal: watch::Receiver) { while !*stop_signal.borrow() { let restart_at = tokio::time::sleep(PING_INTERVAL); let status = self.status.borrow().clone(); let ping_addrs = status .nodes .iter() .filter(|(id, _)| **id != self.id) .map(|(id, status)| (status.addr, Some(*id))) .collect::>(); self.clone().ping_nodes(ping_addrs).await; select! { _ = restart_at.fuse() => (), _ = stop_signal.changed().fuse() => (), } } } async fn discovery_loop( self: Arc, bootstrap_peers: Vec, mut stop_signal: watch::Receiver, ) { while !*stop_signal.borrow() { let not_configured = self.ring.borrow().config.members.len() == 0; let no_peers = self.status.borrow().nodes.len() < 3; let bad_peers = self .status .borrow() .nodes .iter() .filter(|(_, v)| !v.is_up()) .count() != self.ring.borrow().config.members.len(); if not_configured || no_peers || bad_peers { info!("Doing a bootstrap/discovery step (not_configured: {}, no_peers: {}, bad_peers: {})", not_configured, no_peers, bad_peers); let mut bp2 = bootstrap_peers .iter() .map(|ip| (*ip, None)) .collect::>(); match self.persist_status.load_async().await { Ok(peers) => { bp2.extend(peers.iter().map(|x| (x.addr, Some(x.id)))); } _ => (), } self.clone().ping_nodes(bp2).await; } let restart_at = tokio::time::sleep(DISCOVERY_INTERVAL); select! { _ = restart_at.fuse() => (), _ = stop_signal.changed().fuse() => (), } } } async fn consul_loop( self: Arc, mut stop_signal: watch::Receiver, consul_host: String, consul_service_name: String, ) { while !*stop_signal.borrow() { match get_consul_nodes(&consul_host, &consul_service_name).await { Ok(mut node_list) => { let ping_addrs = node_list.drain(..).map(|a| (a, None)).collect::>(); self.clone().ping_nodes(ping_addrs).await; } Err(e) => { warn!("Could not retrieve node list from Consul: {}", e); } } let restart_at = tokio::time::sleep(DISCOVERY_INTERVAL); select! { _ = restart_at.fuse() => (), _ = stop_signal.changed().fuse() => (), } } } fn pull_status( self: Arc, peer: UUID, ) -> impl futures::future::Future + Send + 'static { async move { let resp = self .rpc_client .call(peer, Message::PullStatus, PING_TIMEOUT) .await; if let Ok(Message::AdvertiseNodesUp(nodes)) = resp { let _: Result<_, _> = self.handle_advertise_nodes_up(&nodes).await; } } } async fn pull_config(self: Arc, peer: UUID) { let resp = self .rpc_client .call(peer, Message::PullConfig, PING_TIMEOUT) .await; if let Ok(Message::AdvertiseConfig(config)) = resp { let _: Result<_, _> = self.handle_advertise_config(&config).await; } } async fn update_status(self: &Arc, updaters: &Updaters, status: Status) { if status.hash != self.status.borrow().hash { info!("Persisting new peer list"); let mut list = status.to_serializable_membership(&self); // Combine with old peer list to make sure no peer is lost match self.persist_status.load_async().await { Ok(old_list) => { for pp in old_list { if !list.iter().any(|np| pp.id == np.id) { list.push(pp); } } } _ => (), } if list.len() > 0 { self.persist_status.save_async(&list).await .expect("Unable to persist peer list"); } } let status = Arc::new(status); updaters .update_status .send(status.clone()) .expect("Could not update internal membership status"); } }