mirror of
https://github.com/deuxfleurs-org/garage.git
synced 2026-08-11 06:46:53 +00:00
(not well tested) use merkle tree for sync
This commit is contained in:
Alex Auvolat
@@ -0,0 +1,632 @@
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use std::collections::VecDeque;
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use std::convert::TryInto;
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use std::sync::{Arc, Mutex};
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use std::time::{Duration, Instant};
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use futures::future::join_all;
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use futures::{pin_mut, select};
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use futures_util::future::*;
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use futures_util::stream::*;
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use rand::Rng;
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use serde::{Deserialize, Serialize};
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use serde_bytes::ByteBuf;
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use tokio::sync::{mpsc, watch};
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use garage_rpc::ring::Ring;
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use garage_util::data::*;
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use garage_util::error::Error;
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use crate::data::*;
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use crate::merkle::*;
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use crate::replication::*;
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use crate::*;
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const TABLE_SYNC_RPC_TIMEOUT: Duration = Duration::from_secs(30);
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// Do anti-entropy every 10 minutes
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const ANTI_ENTROPY_INTERVAL: Duration = Duration::from_secs(10 * 60);
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pub struct TableSyncer<F: TableSchema, R: TableReplication> {
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data: Arc<TableData<F>>,
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aux: Arc<TableAux<F, R>>,
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todo: Mutex<SyncTodo>,
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}
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type RootCk = Vec<(MerklePartition, Hash)>;
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#[derive(Debug, Clone, Copy, Serialize, Deserialize)]
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pub struct PartitionRange {
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begin: MerklePartition,
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// if end is None, go all the way to partition 0xFFFF included
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end: Option<MerklePartition>,
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}
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#[derive(Serialize, Deserialize)]
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pub(crate) enum SyncRPC {
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RootCkHash(PartitionRange, Hash),
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RootCkList(PartitionRange, RootCk),
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CkNoDifference,
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GetNode(MerkleNodeKey),
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Node(MerkleNodeKey, MerkleNode),
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Items(Vec<Arc<ByteBuf>>),
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}
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struct SyncTodo {
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todo: Vec<TodoPartition>,
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}
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#[derive(Debug, Clone)]
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struct TodoPartition {
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range: PartitionRange,
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// Are we a node that stores this partition or not?
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retain: bool,
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}
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impl<F, R> TableSyncer<F, R>
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where
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F: TableSchema + 'static,
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R: TableReplication + 'static,
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{
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pub(crate) fn launch(data: Arc<TableData<F>>, aux: Arc<TableAux<F, R>>) -> Arc<Self> {
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let todo = SyncTodo { todo: vec![] };
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let syncer = Arc::new(Self {
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data: data.clone(),
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aux: aux.clone(),
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todo: Mutex::new(todo),
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});
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let (busy_tx, busy_rx) = mpsc::unbounded_channel();
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let s1 = syncer.clone();
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aux.system.background.spawn_worker(
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format!("table sync watcher for {}", data.name),
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move |must_exit: watch::Receiver<bool>| s1.watcher_task(must_exit, busy_rx),
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);
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let s2 = syncer.clone();
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aux.system.background.spawn_worker(
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format!("table syncer for {}", data.name),
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move |must_exit: watch::Receiver<bool>| s2.syncer_task(must_exit, busy_tx),
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);
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let s3 = syncer.clone();
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tokio::spawn(async move {
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tokio::time::delay_for(Duration::from_secs(20)).await;
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s3.add_full_sync();
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});
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syncer
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}
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async fn watcher_task(
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self: Arc<Self>,
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mut must_exit: watch::Receiver<bool>,
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mut busy_rx: mpsc::UnboundedReceiver<bool>,
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) -> Result<(), Error> {
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let mut ring_recv: watch::Receiver<Arc<Ring>> = self.aux.system.ring.clone();
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let mut nothing_to_do_since = Some(Instant::now());
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while !*must_exit.borrow() {
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let s_ring_recv = ring_recv.recv().fuse();
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let s_busy = busy_rx.recv().fuse();
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let s_must_exit = must_exit.recv().fuse();
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let s_timeout = tokio::time::delay_for(Duration::from_secs(1)).fuse();
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pin_mut!(s_ring_recv, s_busy, s_must_exit, s_timeout);
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select! {
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new_ring_r = s_ring_recv => {
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if new_ring_r.is_some() {
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debug!("({}) Adding ring difference to syncer todo list", self.data.name);
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self.add_full_sync();
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}
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}
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busy_opt = s_busy => {
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if let Some(busy) = busy_opt {
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if busy {
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nothing_to_do_since = None;
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} else {
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if nothing_to_do_since.is_none() {
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nothing_to_do_since = Some(Instant::now());
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}
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}
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}
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}
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must_exit_v = s_must_exit => {
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if must_exit_v.unwrap_or(false) {
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break;
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}
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}
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_ = s_timeout => {
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if nothing_to_do_since.map(|t| Instant::now() - t >= ANTI_ENTROPY_INTERVAL).unwrap_or(false) {
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nothing_to_do_since = None;
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debug!("({}) Adding full sync to syncer todo list", self.data.name);
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self.add_full_sync();
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}
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}
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}
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}
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Ok(())
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}
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pub fn add_full_sync(&self) {
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self.todo
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.lock()
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.unwrap()
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.add_full_sync(&self.data, &self.aux);
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}
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async fn syncer_task(
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self: Arc<Self>,
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mut must_exit: watch::Receiver<bool>,
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busy_tx: mpsc::UnboundedSender<bool>,
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) -> Result<(), Error> {
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while !*must_exit.borrow() {
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let task = self.todo.lock().unwrap().pop_task();
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if let Some(partition) = task {
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busy_tx.send(true)?;
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let res = self
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.clone()
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.sync_partition(&partition, &mut must_exit)
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.await;
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if let Err(e) = res {
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warn!(
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"({}) Error while syncing {:?}: {}",
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self.data.name, partition, e
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);
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}
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} else {
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busy_tx.send(false)?;
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tokio::time::delay_for(Duration::from_secs(1)).await;
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}
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}
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Ok(())
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}
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async fn sync_partition(
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self: Arc<Self>,
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partition: &TodoPartition,
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must_exit: &mut watch::Receiver<bool>,
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) -> Result<(), Error> {
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if partition.retain {
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let my_id = self.aux.system.id;
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let nodes = self
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.aux
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.replication
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.write_nodes(
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&hash_of_merkle_partition(partition.range.begin),
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&self.aux.system,
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)
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.into_iter()
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.filter(|node| *node != my_id)
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.collect::<Vec<_>>();
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debug!(
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"({}) Syncing {:?} with {:?}...",
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self.data.name, partition, nodes
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);
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let mut sync_futures = nodes
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.iter()
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.map(|node| {
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self.clone()
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.do_sync_with(partition.clone(), *node, must_exit.clone())
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})
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.collect::<FuturesUnordered<_>>();
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let mut n_errors = 0;
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while let Some(r) = sync_futures.next().await {
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if let Err(e) = r {
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n_errors += 1;
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warn!("({}) Sync error: {}", self.data.name, e);
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}
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}
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if n_errors > self.aux.replication.max_write_errors() {
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return Err(Error::Message(format!(
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"Sync failed with too many nodes (should have been: {:?}).",
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nodes
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)));
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}
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} else {
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self.offload_partition(
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&hash_of_merkle_partition(partition.range.begin),
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&hash_of_merkle_partition_opt(partition.range.end),
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must_exit,
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)
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.await?;
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}
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Ok(())
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}
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// Offload partition: this partition is not something we are storing,
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// so send it out to all other nodes that store it and delete items locally.
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// We don't bother checking if the remote nodes already have the items,
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// we just batch-send everything. Offloading isn't supposed to happen very often.
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// If any of the nodes that are supposed to store the items is unable to
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// save them, we interrupt the process.
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async fn offload_partition(
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self: &Arc<Self>,
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begin: &Hash,
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end: &Hash,
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must_exit: &mut watch::Receiver<bool>,
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) -> Result<(), Error> {
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let mut counter: usize = 0;
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while !*must_exit.borrow() {
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let mut items = Vec::new();
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for item in self.data.store.range(begin.to_vec()..end.to_vec()) {
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let (key, value) = item?;
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items.push((key.to_vec(), Arc::new(ByteBuf::from(value.as_ref()))));
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if items.len() >= 1024 {
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break;
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}
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}
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if items.len() > 0 {
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let nodes = self
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.aux
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.replication
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.write_nodes(&begin, &self.aux.system)
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.into_iter()
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.collect::<Vec<_>>();
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if nodes.contains(&self.aux.system.id) {
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warn!("Interrupting offload as partitions seem to have changed");
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break;
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}
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counter += 1;
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debug!(
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"Offloading {} items from {:?}..{:?} ({})",
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items.len(),
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begin,
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end,
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counter
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);
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self.offload_items(&items, &nodes[..]).await?;
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} else {
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break;
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}
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}
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Ok(())
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}
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async fn offload_items(
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self: &Arc<Self>,
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items: &Vec<(Vec<u8>, Arc<ByteBuf>)>,
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nodes: &[UUID],
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) -> Result<(), Error> {
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let values = items.iter().map(|(_k, v)| v.clone()).collect::<Vec<_>>();
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let update_msg = Arc::new(TableRPC::<F>::Update(values));
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for res in join_all(nodes.iter().map(|to| {
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self.aux
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.rpc_client
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.call_arc(*to, update_msg.clone(), TABLE_SYNC_RPC_TIMEOUT)
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}))
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.await
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{
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res?;
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}
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// All remote nodes have written those items, now we can delete them locally
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let mut not_removed = 0;
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for (k, v) in items.iter() {
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if !self.data.delete_if_equal(&k[..], &v[..])? {
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not_removed += 1;
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}
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}
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if not_removed > 0 {
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debug!("{} items not removed during offload because they changed in between (trying again...)", not_removed);
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}
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Ok(())
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}
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// ======= SYNCHRONIZATION PROCEDURE -- DRIVER SIDE ======
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fn get_root_ck(&self, range: PartitionRange) -> Result<RootCk, Error> {
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let begin = u16::from_be_bytes(range.begin);
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let range_iter = match range.end {
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Some(end) => {
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let end = u16::from_be_bytes(end);
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begin..=(end - 1)
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}
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None => begin..=0xFFFF,
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};
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let mut ret = vec![];
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for i in range_iter {
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let key = MerkleNodeKey {
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partition: u16::to_be_bytes(i),
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prefix: vec![],
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};
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match self.data.merkle_updater.read_node(&key)? {
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MerkleNode::Empty => (),
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x => {
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ret.push((key.partition, hash_of(&x)?));
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}
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}
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}
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Ok(ret)
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}
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async fn do_sync_with(
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self: Arc<Self>,
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partition: TodoPartition,
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who: UUID,
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must_exit: watch::Receiver<bool>,
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) -> Result<(), Error> {
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let root_ck = self.get_root_ck(partition.range)?;
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let root_ck_hash = hash_of(&root_ck)?;
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// If their root checksum has level > than us, use that as a reference
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let root_resp = self
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.aux
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.rpc_client
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.call(
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who,
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TableRPC::<F>::SyncRPC(SyncRPC::RootCkHash(partition.range, root_ck_hash)),
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TABLE_SYNC_RPC_TIMEOUT,
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)
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.await?;
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let mut todo = match root_resp {
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TableRPC::<F>::SyncRPC(SyncRPC::CkNoDifference) => {
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debug!(
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"({}) Sync {:?} with {:?}: no difference",
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self.data.name, partition, who
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);
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return Ok(());
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}
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TableRPC::<F>::SyncRPC(SyncRPC::RootCkList(_, their_root_ck)) => {
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let join = join_ordered(&root_ck[..], &their_root_ck[..]);
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let mut todo = VecDeque::new();
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for (p, v1, v2) in join.iter() {
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let diff = match (v1, v2) {
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(Some(_), None) | (None, Some(_)) => true,
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(Some(a), Some(b)) => a != b,
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_ => false,
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};
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if diff {
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todo.push_back(MerkleNodeKey {
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partition: **p,
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prefix: vec![],
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});
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}
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}
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debug!(
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"({}) Sync {:?} with {:?}: todo.len() = {}",
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self.data.name,
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partition,
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who,
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todo.len()
|
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);
|
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todo
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}
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x => {
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return Err(Error::Message(format!(
|
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"Invalid respone to RootCkHash RPC: {}",
|
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debug_serialize(x)
|
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)));
|
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}
|
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};
|
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|
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let mut todo_items = vec![];
|
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|
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while !todo.is_empty() && !*must_exit.borrow() {
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let key = todo.pop_front().unwrap();
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let node = self.data.merkle_updater.read_node(&key)?;
|
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|
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match node {
|
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MerkleNode::Empty => {
|
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// They have items we don't have.
|
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// We don't request those items from them, they will send them.
|
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// We only bother with pushing items that differ
|
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}
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MerkleNode::Leaf(ik, _) => {
|
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// Just send that item directly
|
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if let Some(val) = self.data.store.get(ik)? {
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todo_items.push(val.to_vec());
|
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}
|
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}
|
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MerkleNode::Intermediate(l) => {
|
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let remote_node = match self
|
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.aux
|
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.rpc_client
|
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.call(
|
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who,
|
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TableRPC::<F>::SyncRPC(SyncRPC::GetNode(key.clone())),
|
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TABLE_SYNC_RPC_TIMEOUT,
|
||||
)
|
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.await?
|
||||
{
|
||||
TableRPC::<F>::SyncRPC(SyncRPC::Node(_, node)) => node,
|
||||
x => {
|
||||
return Err(Error::Message(format!(
|
||||
"Invalid respone to GetNode RPC: {}",
|
||||
debug_serialize(x)
|
||||
)));
|
||||
}
|
||||
};
|
||||
let int_l2 = match remote_node {
|
||||
MerkleNode::Intermediate(l2) => l2,
|
||||
_ => vec![],
|
||||
};
|
||||
|
||||
let join = join_ordered(&l[..], &int_l2[..]);
|
||||
for (p, v1, v2) in join.into_iter() {
|
||||
let diff = match (v1, v2) {
|
||||
(Some(_), None) | (None, Some(_)) => true,
|
||||
(Some(a), Some(b)) => a != b,
|
||||
_ => false,
|
||||
};
|
||||
if diff {
|
||||
todo.push_back(key.add_byte(*p));
|
||||
}
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
if todo_items.len() >= 256 {
|
||||
self.send_items(who, std::mem::replace(&mut todo_items, vec![]))
|
||||
.await?;
|
||||
}
|
||||
}
|
||||
|
||||
if !todo_items.is_empty() {
|
||||
self.send_items(who, todo_items).await?;
|
||||
}
|
||||
|
||||
Ok(())
|
||||
}
|
||||
|
||||
async fn send_items(&self, who: UUID, item_list: Vec<Vec<u8>>) -> Result<(), Error> {
|
||||
info!(
|
||||
"({}) Sending {} items to {:?}",
|
||||
self.data.name,
|
||||
item_list.len(),
|
||||
who
|
||||
);
|
||||
|
||||
let mut values = vec![];
|
||||
for item in item_list.iter() {
|
||||
if let Some(v) = self.data.store.get(&item[..])? {
|
||||
values.push(Arc::new(ByteBuf::from(v.as_ref())));
|
||||
}
|
||||
}
|
||||
let rpc_resp = self
|
||||
.aux
|
||||
.rpc_client
|
||||
.call(who, TableRPC::<F>::Update(values), TABLE_SYNC_RPC_TIMEOUT)
|
||||
.await?;
|
||||
if let TableRPC::<F>::Ok = rpc_resp {
|
||||
Ok(())
|
||||
} else {
|
||||
Err(Error::Message(format!(
|
||||
"Unexpected response to RPC Update: {}",
|
||||
debug_serialize(&rpc_resp)
|
||||
)))
|
||||
}
|
||||
}
|
||||
|
||||
// ======= SYNCHRONIZATION PROCEDURE -- RECEIVER SIDE ======
|
||||
|
||||
pub(crate) async fn handle_rpc(self: &Arc<Self>, message: &SyncRPC) -> Result<SyncRPC, Error> {
|
||||
match message {
|
||||
SyncRPC::RootCkHash(range, h) => {
|
||||
let root_ck = self.get_root_ck(*range)?;
|
||||
let hash = hash_of(&root_ck)?;
|
||||
if hash == *h {
|
||||
Ok(SyncRPC::CkNoDifference)
|
||||
} else {
|
||||
Ok(SyncRPC::RootCkList(*range, root_ck))
|
||||
}
|
||||
}
|
||||
SyncRPC::GetNode(k) => {
|
||||
let node = self.data.merkle_updater.read_node(&k)?;
|
||||
Ok(SyncRPC::Node(k.clone(), node))
|
||||
}
|
||||
_ => Err(Error::Message(format!("Unexpected sync RPC"))),
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
impl SyncTodo {
|
||||
fn add_full_sync<F: TableSchema, R: TableReplication>(
|
||||
&mut self,
|
||||
data: &TableData<F>,
|
||||
aux: &TableAux<F, R>,
|
||||
) {
|
||||
let my_id = aux.system.id;
|
||||
|
||||
self.todo.clear();
|
||||
|
||||
let ring = aux.system.ring.borrow().clone();
|
||||
let split_points = aux.replication.split_points(&ring);
|
||||
|
||||
for i in 0..split_points.len() {
|
||||
let begin: MerklePartition = {
|
||||
let b = split_points[i];
|
||||
assert_eq!(b.as_slice()[2..], [0u8; 30][..]);
|
||||
b.as_slice()[..2].try_into().unwrap()
|
||||
};
|
||||
|
||||
let end: Option<MerklePartition> = if i + 1 < split_points.len() {
|
||||
let e = split_points[i + 1];
|
||||
assert_eq!(e.as_slice()[2..], [0u8; 30][..]);
|
||||
Some(e.as_slice()[..2].try_into().unwrap())
|
||||
} else {
|
||||
None
|
||||
};
|
||||
|
||||
let begin_hash = hash_of_merkle_partition(begin);
|
||||
let end_hash = hash_of_merkle_partition_opt(end);
|
||||
|
||||
let nodes = aux.replication.replication_nodes(&begin_hash, &ring);
|
||||
|
||||
let retain = nodes.contains(&my_id);
|
||||
if !retain {
|
||||
// Check if we have some data to send, otherwise skip
|
||||
if data.store.range(begin_hash..end_hash).next().is_none() {
|
||||
continue;
|
||||
}
|
||||
}
|
||||
|
||||
self.todo.push(TodoPartition {
|
||||
range: PartitionRange { begin, end },
|
||||
retain,
|
||||
});
|
||||
}
|
||||
}
|
||||
|
||||
fn pop_task(&mut self) -> Option<TodoPartition> {
|
||||
if self.todo.is_empty() {
|
||||
return None;
|
||||
}
|
||||
|
||||
let i = rand::thread_rng().gen_range::<usize, _, _>(0, self.todo.len());
|
||||
if i == self.todo.len() - 1 {
|
||||
self.todo.pop()
|
||||
} else {
|
||||
let replacement = self.todo.pop().unwrap();
|
||||
let ret = std::mem::replace(&mut self.todo[i], replacement);
|
||||
Some(ret)
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
fn hash_of<T: Serialize>(x: &T) -> Result<Hash, Error> {
|
||||
Ok(blake2sum(&rmp_to_vec_all_named(x)?[..]))
|
||||
}
|
||||
|
||||
fn join_ordered<'a, K: Ord + Eq, V1, V2>(
|
||||
x: &'a [(K, V1)],
|
||||
y: &'a [(K, V2)],
|
||||
) -> Vec<(&'a K, Option<&'a V1>, Option<&'a V2>)> {
|
||||
let mut ret = vec![];
|
||||
let mut i = 0;
|
||||
let mut j = 0;
|
||||
while i < x.len() || j < y.len() {
|
||||
if i < x.len() && j < y.len() && x[i].0 == y[j].0 {
|
||||
ret.push((&x[i].0, Some(&x[i].1), Some(&y[j].1)));
|
||||
i += 1;
|
||||
j += 1;
|
||||
} else if i < x.len() && (j == y.len() || x[i].0 < y[j].0) {
|
||||
ret.push((&x[i].0, Some(&x[i].1), None));
|
||||
i += 1;
|
||||
} else if j < y.len() && (i == x.len() || x[i].0 > y[j].0) {
|
||||
ret.push((&x[i].0, None, Some(&y[j].1)));
|
||||
j += 1;
|
||||
} else {
|
||||
unreachable!();
|
||||
}
|
||||
}
|
||||
ret
|
||||
}
|
||||
Reference in New Issue
Block a user