This commit is contained in:
Alex Auvolat 2020-04-16 18:41:10 +02:00
parent e8d750175d
commit 2832be4396
3 changed files with 208 additions and 31 deletions

View file

@ -14,7 +14,7 @@ type Job = Pin<Box<dyn Future<Output = JobOutput> + Send>>;
pub struct BackgroundRunner {
n_runners: usize,
stop_signal: watch::Receiver<bool>,
pub stop_signal: watch::Receiver<bool>,
queue_in: mpsc::UnboundedSender<(Job, bool)>,
queue_out: Mutex<mpsc::UnboundedReceiver<(Job, bool)>>,

View file

@ -4,6 +4,7 @@ use std::time::Duration;
use async_trait::async_trait;
use futures::stream::*;
use tokio::sync::RwLock;
use serde::{Deserialize, Serialize};
use serde_bytes::ByteBuf;
@ -12,7 +13,7 @@ use crate::error::Error;
use crate::membership::System;
use crate::proto::*;
use crate::rpc_client::*;
use crate::table_sync::TableSyncer;
use crate::table_sync::*;
pub struct Table<F: TableSchema> {
pub instance: F,
@ -21,6 +22,7 @@ pub struct Table<F: TableSchema> {
pub system: Arc<System>,
pub store: sled::Tree,
pub syncer: RwLock<Option<Arc<TableSyncer<F>>>>,
pub param: TableReplicationParams,
}
@ -59,6 +61,9 @@ pub enum TableRPC<F: TableSchema> {
ReadEntryResponse(Option<ByteBuf>),
Update(Vec<Arc<ByteBuf>>),
SyncChecksums(Vec<RangeChecksum>),
SyncDifferentSet(Vec<SyncRange>),
}
pub trait PartitionKey {
@ -132,8 +137,10 @@ impl<F: TableSchema + 'static> Table<F> {
system,
store,
param,
syncer: RwLock::new(None),
});
TableSyncer::launch(table.clone()).await;
let syncer = TableSyncer::launch(table.clone()).await;
*table.syncer.write().await = Some(syncer);
table
}
@ -309,6 +316,11 @@ impl<F: TableSchema + 'static> Table<F> {
self.handle_update(pairs).await?;
Ok(TableRPC::Ok)
}
TableRPC::SyncChecksums(checksums) => {
let syncer = self.syncer.read().await.as_ref().unwrap().clone();
let differing = syncer.handle_checksum_rpc(&checksums[..], self.system.background.stop_signal.clone()).await?;
Ok(TableRPC::SyncDifferentSet(differing))
}
_ => Err(Error::RPCError(format!("Unexpected table RPC"))),
}
}
@ -353,6 +365,11 @@ impl<F: TableSchema + 'static> Table<F> {
Ok(())
}
pub async fn delete_range(&self, begin: &Hash, end: &Hash) -> Result<(), Error> {
// TODO
Ok(())
}
fn tree_key(&self, p: &F::P, s: &F::S) -> Vec<u8> {
let mut ret = p.hash().to_vec();
ret.extend(s.sort_key());

View file

@ -1,12 +1,15 @@
use rand::Rng;
use std::collections::BTreeSet;
use std::collections::{BTreeSet, HashMap, VecDeque};
use std::sync::Arc;
use std::time::Duration;
use std::time::{Duration, Instant};
use futures::{pin_mut, select};
use futures::future::BoxFuture;
use futures_util::stream::*;
use futures_util::future::*;
use tokio::sync::watch;
use tokio::sync::Mutex;
use serde::{Serialize, Deserialize};
use crate::data::*;
use crate::error::Error;
@ -14,11 +17,12 @@ use crate::membership::Ring;
use crate::table::*;
const SCAN_INTERVAL: Duration = Duration::from_secs(3600);
const CHECKSUM_CACHE_TIMEOUT: Duration = Duration::from_secs(1800);
pub struct TableSyncer<F: TableSchema> {
pub table: Arc<Table<F>>,
pub todo: Mutex<SyncTodo>,
pub cache: Vec<Mutex<HashMap<SyncRange, RangeChecksum>>>,
}
pub struct SyncTodo {
@ -32,12 +36,30 @@ pub struct Partition {
pub retain: bool,
}
#[derive(Hash, PartialEq, Eq, Debug, Clone, Serialize, Deserialize)]
pub struct SyncRange {
pub begin: Vec<u8>,
pub end: Vec<u8>,
pub level: usize,
}
#[derive(Debug, Clone, Serialize, Deserialize)]
pub struct RangeChecksum {
pub bounds: SyncRange,
pub children: Vec<(SyncRange, Hash)>,
pub found_limit: Option<Vec<u8>>,
#[serde(skip, default="std::time::Instant::now")]
pub time: Instant,
}
impl<F: TableSchema + 'static> TableSyncer<F> {
pub async fn launch(table: Arc<Table<F>>) -> Arc<Self> {
let todo = SyncTodo { todo: Vec::new() };
let syncer = Arc::new(TableSyncer {
table: table.clone(),
todo: Mutex::new(todo),
cache: (0..32).map(|_| Mutex::new(HashMap::new())).collect::<Vec<_>>(),
});
let s1 = syncer.clone();
@ -95,38 +117,176 @@ impl<F: TableSchema + 'static> TableSyncer<F> {
self: Arc<Self>,
mut must_exit: watch::Receiver<bool>,
) -> Result<(), Error> {
loop {
let s_pop_task = self.pop_task().fuse();
let s_must_exit = must_exit.recv().fuse();
pin_mut!(s_must_exit, s_pop_task);
while !*must_exit.borrow() {
if let Some(partition) = self.todo.lock().await.pop_task() {
let res = self.clone().sync_partition(&partition, &mut must_exit).await;
if let Err(e) = res {
eprintln!("Error while syncing {:?}: {}", partition, e);
}
} else {
tokio::time::delay_for(Duration::from_secs(1)).await;
}
}
Ok(())
}
select! {
task = s_pop_task => {
if let Some(partition) = task {
let res = self.sync_partition(&partition).await;
if let Err(e) = res {
eprintln!("Error while syncing {:?}: {}", partition, e);
}
} else {
tokio::time::delay_for(Duration::from_secs(1)).await;
async fn sync_partition(self: Arc<Self>, partition: &Partition, must_exit: &mut watch::Receiver<bool>) -> Result<(), Error> {
let root_cks = self.root_checksum(&partition.begin, &partition.end, must_exit).await?;
eprintln!("Root checksum for {:?}: {:?}", partition, root_cks);
let nodes = self.table.system.ring.borrow().clone().walk_ring(&partition.begin, self.table.param.replication_factor);
let mut sync_futures = nodes.iter()
.map(|node| self.clone().do_sync_with(root_cks.clone(), node.clone(), must_exit.clone()))
.collect::<FuturesUnordered<_>>();
while let Some(r) = sync_futures.next().await {
if let Err(e) = r {
eprintln!("Sync error: {}", e);
}
}
if !partition.retain {
self.table.delete_range(&partition.begin, &partition.end).await?;
}
Ok(())
}
async fn root_checksum(self: &Arc<Self>, begin: &Hash, end: &Hash, must_exit: &mut watch::Receiver<bool>) -> Result<RangeChecksum, Error> {
for i in 1..32 {
let rc = self.range_checksum(&SyncRange{
begin: begin.to_vec(),
end: end.to_vec(),
level: i,
}, must_exit).await?;
if rc.found_limit.is_none() {
return Ok(rc);
}
}
Err(Error::Message(format!("Unable to compute root checksum (this should never happen")))
}
fn range_checksum<'a>(self: &'a Arc<Self>, range: &'a SyncRange, must_exit: &'a mut watch::Receiver<bool>) -> BoxFuture<'a, Result<RangeChecksum, Error>> {
async move {
let mut cache = self.cache[range.level].lock().await;
if let Some(v) = cache.get(&range) {
if Instant::now() - v.time < CHECKSUM_CACHE_TIMEOUT {
return Ok(v.clone());
}
}
cache.remove(&range);
drop(cache);
let v = self.range_checksum_inner(&range, must_exit).await?;
let mut cache = self.cache[range.level].lock().await;
eprintln!("Checksum for {:?}: {:?}", range, v);
cache.insert(range.clone(), v.clone());
Ok(v)
}.boxed()
}
async fn range_checksum_inner(self: &Arc<Self>, range: &SyncRange, must_exit: &mut watch::Receiver<bool>) -> Result<RangeChecksum, Error> {
if range.level == 1 {
let mut children = vec![];
for item in self.table.store.range(range.begin.clone()..range.end.clone()) {
let (key, value) = item?;
let key_hash = hash(&key[..]);
if key != range.begin && key_hash.as_slice()[0..range.level].iter().all(|x| *x == 0) {
return Ok(RangeChecksum{
bounds: range.clone(),
children,
found_limit: Some(key.to_vec()),
time: Instant::now(),
})
}
let item_range = SyncRange{
begin: key.to_vec(),
end: vec![],
level: 0,
};
children.push((item_range, hash(&value[..])));
}
Ok(RangeChecksum{
bounds: range.clone(),
children,
found_limit: None,
time: Instant::now(),
})
} else {
let mut children = vec![];
let mut sub_range = SyncRange{
begin: range.begin.clone(),
end: range.end.clone(),
level: range.level - 1,
};
let mut time = Instant::now();
while !*must_exit.borrow() {
let sub_ck = self.range_checksum(&sub_range, must_exit).await?;
if sub_ck.children.len() > 0 {
let sub_ck_hash = hash(&rmp_to_vec_all_named(&sub_ck)?[..]);
children.push((sub_range.clone(), sub_ck_hash));
if sub_ck.time < time {
time = sub_ck.time;
}
}
must_exit_v = s_must_exit => {
if must_exit_v.unwrap_or(false) {
return Ok(())
if sub_ck.found_limit.is_none() || sub_ck.children.len() == 0 {
return Ok(RangeChecksum{
bounds: range.clone(),
children,
found_limit: None,
time,
});
}
let found_limit = sub_ck.found_limit.unwrap();
let actual_limit_hash = hash(&found_limit[..]);
if actual_limit_hash.as_slice()[0..range.level].iter().all(|x| *x == 0) {
return Ok(RangeChecksum{
bounds: range.clone(),
children,
found_limit: Some(found_limit.clone()),
time,
});
}
sub_range.begin = found_limit;
}
Err(Error::Message(format!("Exiting.")))
}
}
async fn do_sync_with(self: Arc<Self>, root_ck: RangeChecksum, who: UUID, mut must_exit: watch::Receiver<bool>) -> Result<(), Error> {
let mut todo = VecDeque::new();
todo.push_back(root_ck);
while !todo.is_empty() && !*must_exit.borrow() {
let end = std::cmp::min(16, todo.len());
let step = todo.drain(..end).collect::<Vec<_>>();
unimplemented!()
}
Ok(())
}
pub async fn handle_checksum_rpc(self: &Arc<Self>, checksums: &[RangeChecksum], mut must_exit: watch::Receiver<bool>) -> Result<Vec<SyncRange>, Error> {
let mut ret = vec![];
for ckr in checksums.iter() {
let our_ckr = self.range_checksum(&ckr.bounds, &mut must_exit).await?;
for (range, hash) in ckr.children.iter() {
match our_ckr.children.binary_search_by(|(our_range, _)| our_range.begin.cmp(&range.begin)) {
Err(_) => {
ret.push(range.clone());
}
Ok(i) => {
if our_ckr.children[i].1 != *hash {
ret.push(range.clone());
}
}
}
}
}
}
async fn pop_task(&self) -> Option<Partition> {
self.todo.lock().await.pop_task()
}
async fn sync_partition(self: &Arc<Self>, partition: &Partition) -> Result<(), Error> {
eprintln!("NOT IMPLEMENTED: SYNC PARTITION {:?}", partition);
Ok(())
Ok(ret)
}
}