garage/src/membership.rs
2020-04-07 00:00:43 +02:00

311 lines
8.2 KiB
Rust

use std::sync::Arc;
use std::collections::HashMap;
use std::time::Duration;
use std::net::{IpAddr, SocketAddr};
use futures::future::join_all;
use hyper::client::Client;
use tokio::sync::RwLock;
use sha2::{Sha256, Digest};
use crate::Config;
use crate::error::Error;
use crate::data::*;
use crate::proto::*;
use crate::rpc::*;
const PING_INTERVAL: Duration = Duration::from_secs(10);
const PING_TIMEOUT: Duration = Duration::from_secs(2);
const MAX_FAILED_PINGS: usize = 3;
pub struct System {
pub config: Config,
pub id: UUID,
pub rpc_client: Client<hyper::client::HttpConnector, hyper::Body>,
pub members: RwLock<Members>,
}
pub struct Members {
pub status: HashMap<UUID, NodeStatus>,
pub status_hash: Hash,
pub config: NetworkConfig,
}
impl Members {
fn handle_ping(&mut self, ip: IpAddr, info: &PingMessage) -> bool {
let addr = SocketAddr::new(ip, info.rpc_port);
let old_status = self.status.insert(info.id.clone(),
NodeStatus{
addr: addr.clone(),
remaining_ping_attempts: MAX_FAILED_PINGS,
datacenter: info.datacenter.clone(),
});
match old_status {
None => {
eprintln!("Newly pingable node: {}", hex::encode(info.id));
true
}
Some(x) => x.addr != addr,
}
}
fn recalculate_status_hash(&mut self) {
let mut nodes = self.status.iter().collect::<Vec<_>>();
nodes.sort_by_key(|(id, _status)| *id);
let mut hasher = Sha256::new();
eprintln!("Current set of pingable nodes: --");
for (id, status) in nodes {
eprintln!("{} {} ({})", hex::encode(id), status.addr, status.datacenter);
hasher.input(format!("{} {}\n", hex::encode(id), status.addr));
}
eprintln!("END --");
self.status_hash.copy_from_slice(&hasher.result()[..]);
}
}
pub struct NodeStatus {
pub addr: SocketAddr,
pub datacenter: String,
pub remaining_ping_attempts: usize,
}
impl System {
pub fn new(config: Config, id: UUID) -> Self {
let mut members = Members{
status: HashMap::new(),
status_hash: [0u8; 32],
config: NetworkConfig{
members: HashMap::new(),
version: 0,
},
};
members.recalculate_status_hash();
System{
config,
id,
rpc_client: Client::new(),
members: RwLock::new(members),
}
}
pub async fn make_ping(&self) -> Message {
let members = self.members.read().await;
Message::Ping(PingMessage{
id: self.id,
datacenter: self.config.datacenter.clone(),
rpc_port: self.config.rpc_port,
status_hash: members.status_hash.clone(),
config_version: members.config.version,
})
}
pub async fn broadcast(self: Arc<Self>, msg: Message, timeout: Duration) {
let members = self.members.read().await;
let to = members.status.keys().filter(|x| **x != self.id).cloned().collect::<Vec<_>>();
drop(members);
rpc_call_many(self.clone(), &to[..], &msg, None, timeout).await;
}
pub async fn bootstrap(self: Arc<Self>) {
let bootstrap_peers = self.config.bootstrap_peers
.iter()
.map(|ip| (ip.clone(), None))
.collect::<Vec<_>>();
self.clone().ping_nodes(bootstrap_peers).await;
tokio::spawn(self.ping_loop());
}
pub async fn ping_nodes(self: Arc<Self>, peers: Vec<(SocketAddr, Option<UUID>)>) {
let ping_msg = self.make_ping().await;
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.clone(), rpc_call_addr(sys, &addr, ping_msg_ref, PING_TIMEOUT).await)
}
})).await;
let mut members = self.members.write().await;
let mut has_changes = false;
let mut to_advertise = vec![];
for (id_option, addr, ping_resp) in ping_resps {
if let Ok(Message::Ping(info)) = ping_resp {
let is_new = members.handle_ping(addr.ip(), &info);
if is_new {
has_changes = true;
to_advertise.push(AdvertisedNode{
id: info.id.clone(),
addr: addr.clone(),
});
}
if is_new || members.status_hash != info.status_hash {
tokio::spawn(self.clone().pull_status(info.id.clone()));
}
if is_new || members.config.version < info.config_version {
tokio::spawn(self.clone().pull_config(info.id.clone()));
}
} else if let Some(id) = id_option {
let remaining_attempts = members.status.get(id).map(|x| x.remaining_ping_attempts).unwrap_or(0);
if remaining_attempts == 0 {
eprintln!("Removing node {} after too many failed pings", hex::encode(id));
members.status.remove(id);
has_changes = true;
} else {
if let Some(st) = members.status.get_mut(id) {
st.remaining_ping_attempts = remaining_attempts - 1;
}
}
}
}
if has_changes {
members.recalculate_status_hash();
}
drop(members);
if to_advertise.len() > 0 {
self.broadcast(Message::AdvertiseNodesUp(to_advertise), PING_TIMEOUT).await;
}
}
pub async fn handle_ping(self: Arc<Self>,
from: &SocketAddr,
ping: &PingMessage)
-> Result<Message, Error>
{
let mut members = self.members.write().await;
let is_new = members.handle_ping(from.ip(), ping);
if is_new {
members.recalculate_status_hash();
}
let status_hash = members.status_hash.clone();
let config_version = members.config.version;
drop(members);
if is_new || status_hash != ping.status_hash {
tokio::spawn(self.clone().pull_status(ping.id.clone()));
}
if is_new || config_version < ping.config_version {
tokio::spawn(self.clone().pull_config(ping.id.clone()));
}
Ok(self.make_ping().await)
}
pub async fn handle_pull_status(&self) -> Result<Message, Error> {
let members = self.members.read().await;
let mut mem = vec![];
for (node, status) in members.status.iter() {
mem.push(AdvertisedNode{
id: node.clone(),
addr: status.addr.clone(),
});
}
Ok(Message::AdvertiseNodesUp(mem))
}
pub async fn handle_pull_config(&self) -> Result<Message, Error> {
let members = self.members.read().await;
Ok(Message::AdvertiseConfig(members.config.clone()))
}
pub async fn handle_advertise_nodes_up(self: Arc<Self>,
adv: &[AdvertisedNode])
-> Result<Message, Error>
{
let mut to_ping = vec![];
let mut members = self.members.write().await;
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.config.rpc_port);
let old_self = members.status.insert(node.id.clone(),
NodeStatus{
addr: self_addr,
datacenter: self.config.datacenter.clone(),
remaining_ping_attempts: MAX_FAILED_PINGS,
});
has_changed = match old_self {
None => true,
Some(x) => x.addr != self_addr,
};
} else if !members.status.contains_key(&node.id) {
to_ping.push((node.addr.clone(), Some(node.id.clone())));
}
}
if has_changed {
members.recalculate_status_hash();
}
drop(members);
if to_ping.len() > 0 {
tokio::spawn(self.clone().ping_nodes(to_ping));
}
Ok(Message::Ok)
}
pub async fn handle_advertise_config(self: Arc<Self>,
adv: &NetworkConfig)
-> Result<Message, Error>
{
let mut members = self.members.write().await;
if adv.version > members.config.version {
members.config = adv.clone();
tokio::spawn(self.clone().broadcast(Message::AdvertiseConfig(adv.clone()), PING_TIMEOUT));
}
Ok(Message::Ok)
}
pub async fn ping_loop(self: Arc<Self>) {
loop {
let restart_at = tokio::time::delay_for(PING_INTERVAL);
let members = self.members.read().await;
let ping_addrs = members.status.iter()
.filter(|(id, _)| **id != self.id)
.map(|(id, status)| (status.addr.clone(), Some(id.clone())))
.collect::<Vec<_>>();
drop(members);
self.clone().ping_nodes(ping_addrs).await;
restart_at.await
}
}
pub fn pull_status(self: Arc<Self>, peer: UUID) -> impl futures::future::Future<Output=()> + Send + 'static {
async move {
let resp = rpc_call(self.clone(),
&peer,
&Message::PullStatus,
PING_TIMEOUT).await;
if let Ok(Message::AdvertiseNodesUp(nodes)) = resp {
let _: Result<_, _> = self.handle_advertise_nodes_up(&nodes).await;
}
}
}
pub async fn pull_config(self: Arc<Self>, peer: UUID) {
let resp = rpc_call(self.clone(),
&peer,
&Message::PullConfig,
PING_TIMEOUT).await;
if let Ok(Message::AdvertiseConfig(config)) = resp {
let _: Result<_, _> = self.handle_advertise_config(&config).await;
}
}
}