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authorAlex Auvolat <alex@adnab.me>2020-07-07 13:59:22 +0200
committerAlex Auvolat <alex@adnab.me>2020-07-07 13:59:22 +0200
commitbec26a13129d8215d5ff97ad0cf587f6572f67ac (patch)
tree8a183bb7f1c4878c2ccc8a53ff799318647540e5 /src/model/block.rs
parentf0918b377e428f4d7a6afa341cb92bc49dfcac1b (diff)
downloadgarage-bec26a13129d8215d5ff97ad0cf587f6572f67ac.tar.gz
garage-bec26a13129d8215d5ff97ad0cf587f6572f67ac.zip
Rename garage_core to garage_model
Diffstat (limited to 'src/model/block.rs')
-rw-r--r--src/model/block.rs506
1 files changed, 506 insertions, 0 deletions
diff --git a/src/model/block.rs b/src/model/block.rs
new file mode 100644
index 00000000..af8b9efb
--- /dev/null
+++ b/src/model/block.rs
@@ -0,0 +1,506 @@
+use std::path::PathBuf;
+use std::sync::Arc;
+use std::time::Duration;
+
+use arc_swap::ArcSwapOption;
+use futures::future::*;
+use futures::select;
+use futures::stream::*;
+use serde::{Deserialize, Serialize};
+use tokio::fs;
+use tokio::prelude::*;
+use tokio::sync::{watch, Mutex, Notify};
+
+use garage_util::data;
+use garage_util::data::*;
+use garage_util::error::Error;
+
+use garage_rpc::membership::System;
+use garage_rpc::rpc_client::*;
+use garage_rpc::rpc_server::*;
+
+use garage_table::table_sharded::TableShardedReplication;
+use garage_table::TableReplication;
+
+use crate::block_ref_table::*;
+
+use crate::garage::Garage;
+
+pub const INLINE_THRESHOLD: usize = 3072;
+
+const BLOCK_RW_TIMEOUT: Duration = Duration::from_secs(42);
+const NEED_BLOCK_QUERY_TIMEOUT: Duration = Duration::from_secs(5);
+const RESYNC_RETRY_TIMEOUT: Duration = Duration::from_secs(10);
+
+#[derive(Debug, Serialize, Deserialize)]
+pub enum Message {
+ Ok,
+ GetBlock(Hash),
+ PutBlock(PutBlockMessage),
+ NeedBlockQuery(Hash),
+ NeedBlockReply(bool),
+}
+
+#[derive(Debug, Serialize, Deserialize)]
+pub struct PutBlockMessage {
+ pub hash: Hash,
+
+ #[serde(with = "serde_bytes")]
+ pub data: Vec<u8>,
+}
+
+impl RpcMessage for Message {}
+
+pub struct BlockManager {
+ pub replication: TableShardedReplication,
+ pub data_dir: PathBuf,
+ pub data_dir_lock: Mutex<()>,
+
+ pub rc: sled::Tree,
+
+ pub resync_queue: sled::Tree,
+ pub resync_notify: Notify,
+
+ pub system: Arc<System>,
+ rpc_client: Arc<RpcClient<Message>>,
+ pub garage: ArcSwapOption<Garage>,
+}
+
+impl BlockManager {
+ pub fn new(
+ db: &sled::Db,
+ data_dir: PathBuf,
+ replication: TableShardedReplication,
+ system: Arc<System>,
+ rpc_server: &mut RpcServer,
+ ) -> Arc<Self> {
+ let rc = db
+ .open_tree("block_local_rc")
+ .expect("Unable to open block_local_rc tree");
+ rc.set_merge_operator(rc_merge);
+
+ let resync_queue = db
+ .open_tree("block_local_resync_queue")
+ .expect("Unable to open block_local_resync_queue tree");
+
+ let rpc_path = "block_manager";
+ let rpc_client = system.rpc_client::<Message>(rpc_path);
+
+ let block_manager = Arc::new(Self {
+ replication,
+ data_dir,
+ data_dir_lock: Mutex::new(()),
+ rc,
+ resync_queue,
+ resync_notify: Notify::new(),
+ system,
+ rpc_client,
+ garage: ArcSwapOption::from(None),
+ });
+ block_manager
+ .clone()
+ .register_handler(rpc_server, rpc_path.into());
+ block_manager
+ }
+
+ fn register_handler(self: Arc<Self>, rpc_server: &mut RpcServer, path: String) {
+ let self2 = self.clone();
+ rpc_server.add_handler::<Message, _, _>(path, move |msg, _addr| {
+ let self2 = self2.clone();
+ async move { self2.handle(&msg).await }
+ });
+
+ let self2 = self.clone();
+ self.rpc_client
+ .set_local_handler(self.system.id, move |msg| {
+ let self2 = self2.clone();
+ async move { self2.handle(&msg).await }
+ });
+ }
+
+ async fn handle(self: Arc<Self>, msg: &Message) -> Result<Message, Error> {
+ match msg {
+ Message::PutBlock(m) => self.write_block(&m.hash, &m.data).await,
+ Message::GetBlock(h) => self.read_block(h).await,
+ Message::NeedBlockQuery(h) => self.need_block(h).await.map(Message::NeedBlockReply),
+ _ => Err(Error::BadRequest(format!("Unexpected RPC message"))),
+ }
+ }
+
+ pub async fn spawn_background_worker(self: Arc<Self>) {
+ // Launch 2 simultaneous workers for background resync loop preprocessing
+ for i in 0..2usize {
+ let bm2 = self.clone();
+ let background = self.system.background.clone();
+ tokio::spawn(async move {
+ tokio::time::delay_for(Duration::from_secs(10)).await;
+ background
+ .spawn_worker(format!("block resync worker {}", i), move |must_exit| {
+ bm2.resync_loop(must_exit)
+ })
+ .await;
+ });
+ }
+ }
+
+ pub async fn write_block(&self, hash: &Hash, data: &[u8]) -> Result<Message, Error> {
+ let _lock = self.data_dir_lock.lock().await;
+
+ let mut path = self.block_dir(hash);
+ fs::create_dir_all(&path).await?;
+
+ path.push(hex::encode(hash));
+ if fs::metadata(&path).await.is_ok() {
+ return Ok(Message::Ok);
+ }
+
+ let mut f = fs::File::create(path).await?;
+ f.write_all(data).await?;
+ drop(f);
+
+ Ok(Message::Ok)
+ }
+
+ pub async fn read_block(&self, hash: &Hash) -> Result<Message, Error> {
+ let path = self.block_path(hash);
+
+ let mut f = match fs::File::open(&path).await {
+ Ok(f) => f,
+ Err(e) => {
+ // Not found but maybe we should have had it ??
+ self.put_to_resync(hash, 0)?;
+ return Err(Into::into(e));
+ }
+ };
+ let mut data = vec![];
+ f.read_to_end(&mut data).await?;
+ drop(f);
+
+ if data::hash(&data[..]) != *hash {
+ let _lock = self.data_dir_lock.lock().await;
+ warn!("Block {:?} is corrupted. Deleting and resyncing.", hash);
+ fs::remove_file(path).await?;
+ self.put_to_resync(&hash, 0)?;
+ return Err(Error::CorruptData(*hash));
+ }
+
+ Ok(Message::PutBlock(PutBlockMessage { hash: *hash, data }))
+ }
+
+ pub async fn need_block(&self, hash: &Hash) -> Result<bool, Error> {
+ let needed = self
+ .rc
+ .get(hash.as_ref())?
+ .map(|x| u64_from_bytes(x.as_ref()) > 0)
+ .unwrap_or(false);
+ if needed {
+ let path = self.block_path(hash);
+ let exists = fs::metadata(&path).await.is_ok();
+ Ok(!exists)
+ } else {
+ Ok(false)
+ }
+ }
+
+ fn block_dir(&self, hash: &Hash) -> PathBuf {
+ let mut path = self.data_dir.clone();
+ path.push(hex::encode(&hash.as_slice()[0..1]));
+ path.push(hex::encode(&hash.as_slice()[1..2]));
+ path
+ }
+ fn block_path(&self, hash: &Hash) -> PathBuf {
+ let mut path = self.block_dir(hash);
+ path.push(hex::encode(hash.as_ref()));
+ path
+ }
+
+ pub fn block_incref(&self, hash: &Hash) -> Result<(), Error> {
+ let old_rc = self.rc.get(&hash)?;
+ self.rc.merge(&hash, vec![1])?;
+ if old_rc.map(|x| u64_from_bytes(&x[..]) == 0).unwrap_or(true) {
+ self.put_to_resync(&hash, BLOCK_RW_TIMEOUT.as_millis() as u64)?;
+ }
+ Ok(())
+ }
+
+ pub fn block_decref(&self, hash: &Hash) -> Result<(), Error> {
+ let new_rc = self.rc.merge(&hash, vec![0])?;
+ if new_rc.map(|x| u64_from_bytes(&x[..]) == 0).unwrap_or(true) {
+ self.put_to_resync(&hash, 0)?;
+ }
+ Ok(())
+ }
+
+ fn put_to_resync(&self, hash: &Hash, delay_millis: u64) -> Result<(), Error> {
+ let when = now_msec() + delay_millis;
+ trace!("Put resync_queue: {} {:?}", when, hash);
+ let mut key = u64::to_be_bytes(when).to_vec();
+ key.extend(hash.as_ref());
+ self.resync_queue.insert(key, hash.as_ref())?;
+ self.resync_notify.notify();
+ Ok(())
+ }
+
+ async fn resync_loop(
+ self: Arc<Self>,
+ mut must_exit: watch::Receiver<bool>,
+ ) -> Result<(), Error> {
+ let mut n_failures = 0usize;
+ while !*must_exit.borrow() {
+ if let Some((time_bytes, hash_bytes)) = self.resync_queue.pop_min()? {
+ let time_msec = u64_from_bytes(&time_bytes[0..8]);
+ let now = now_msec();
+ if now >= time_msec {
+ let mut hash = [0u8; 32];
+ hash.copy_from_slice(hash_bytes.as_ref());
+ let hash = Hash::from(hash);
+
+ if let Err(e) = self.resync_iter(&hash).await {
+ warn!("Failed to resync block {:?}, retrying later: {}", hash, e);
+ self.put_to_resync(&hash, RESYNC_RETRY_TIMEOUT.as_millis() as u64)?;
+ n_failures += 1;
+ if n_failures >= 10 {
+ warn!("Too many resync failures, throttling.");
+ tokio::time::delay_for(Duration::from_secs(1)).await;
+ }
+ } else {
+ n_failures = 0;
+ }
+ } else {
+ self.resync_queue.insert(time_bytes, hash_bytes)?;
+ let delay = tokio::time::delay_for(Duration::from_millis(time_msec - now));
+ select! {
+ _ = delay.fuse() => (),
+ _ = self.resync_notify.notified().fuse() => (),
+ _ = must_exit.recv().fuse() => (),
+ }
+ }
+ } else {
+ select! {
+ _ = self.resync_notify.notified().fuse() => (),
+ _ = must_exit.recv().fuse() => (),
+ }
+ }
+ }
+ Ok(())
+ }
+
+ async fn resync_iter(&self, hash: &Hash) -> Result<(), Error> {
+ let path = self.block_path(hash);
+
+ let exists = fs::metadata(&path).await.is_ok();
+ let needed = self
+ .rc
+ .get(hash.as_ref())?
+ .map(|x| u64_from_bytes(x.as_ref()) > 0)
+ .unwrap_or(false);
+
+ if exists != needed {
+ info!(
+ "Resync block {:?}: exists {}, needed {}",
+ hash, exists, needed
+ );
+ }
+
+ if exists && !needed {
+ let garage = self.garage.load_full().unwrap();
+ let active_refs = garage
+ .block_ref_table
+ .get_range(&hash, None, Some(()), 1)
+ .await?;
+ let needed_by_others = !active_refs.is_empty();
+ if needed_by_others {
+ let ring = self.system.ring.borrow().clone();
+ let who = self.replication.replication_nodes(&hash, &ring);
+ let msg = Arc::new(Message::NeedBlockQuery(*hash));
+ let who_needs_fut = who.iter().map(|to| {
+ self.rpc_client
+ .call_arc(*to, msg.clone(), NEED_BLOCK_QUERY_TIMEOUT)
+ });
+ let who_needs = join_all(who_needs_fut).await;
+
+ let mut need_nodes = vec![];
+ for (node, needed) in who.into_iter().zip(who_needs.iter()) {
+ match needed {
+ Ok(Message::NeedBlockReply(needed)) => {
+ if *needed {
+ need_nodes.push(node);
+ }
+ }
+ Err(e) => {
+ return Err(Error::Message(format!(
+ "Should delete block, but unable to confirm that all other nodes that need it have it: {}",
+ e
+ )));
+ }
+ Ok(_) => {
+ return Err(Error::Message(format!(
+ "Unexpected response to NeedBlockQuery RPC"
+ )));
+ }
+ }
+ }
+
+ if need_nodes.len() > 0 {
+ let put_block_message = self.read_block(hash).await?;
+ self.rpc_client
+ .try_call_many(
+ &need_nodes[..],
+ put_block_message,
+ RequestStrategy::with_quorum(need_nodes.len())
+ .with_timeout(BLOCK_RW_TIMEOUT),
+ )
+ .await?;
+ }
+ }
+ fs::remove_file(path).await?;
+ self.resync_queue.remove(&hash)?;
+ }
+
+ if needed && !exists {
+ // TODO find a way to not do this if they are sending it to us
+ // Let's suppose this isn't an issue for now with the BLOCK_RW_TIMEOUT delay
+ // between the RC being incremented and this part being called.
+ let block_data = self.rpc_get_block(&hash).await?;
+ self.write_block(hash, &block_data[..]).await?;
+ }
+
+ Ok(())
+ }
+
+ pub async fn rpc_get_block(&self, hash: &Hash) -> Result<Vec<u8>, Error> {
+ let who = self.replication.read_nodes(&hash, &self.system);
+ let resps = self
+ .rpc_client
+ .try_call_many(
+ &who[..],
+ Message::GetBlock(*hash),
+ RequestStrategy::with_quorum(1)
+ .with_timeout(BLOCK_RW_TIMEOUT)
+ .interrupt_after_quorum(true),
+ )
+ .await?;
+
+ for resp in resps {
+ if let Message::PutBlock(msg) = resp {
+ return Ok(msg.data);
+ }
+ }
+ Err(Error::Message(format!(
+ "Unable to read block {:?}: no valid blocks returned",
+ hash
+ )))
+ }
+
+ pub async fn rpc_put_block(&self, hash: Hash, data: Vec<u8>) -> Result<(), Error> {
+ let who = self.replication.write_nodes(&hash, &self.system);
+ self.rpc_client
+ .try_call_many(
+ &who[..],
+ Message::PutBlock(PutBlockMessage { hash, data }),
+ RequestStrategy::with_quorum(self.replication.write_quorum())
+ .with_timeout(BLOCK_RW_TIMEOUT),
+ )
+ .await?;
+ Ok(())
+ }
+
+ pub async fn repair_data_store(&self, must_exit: &watch::Receiver<bool>) -> Result<(), Error> {
+ // 1. Repair blocks from RC table
+ let garage = self.garage.load_full().unwrap();
+ let mut last_hash = None;
+ let mut i = 0usize;
+ for entry in garage.block_ref_table.store.iter() {
+ let (_k, v_bytes) = entry?;
+ let block_ref = rmp_serde::decode::from_read_ref::<_, BlockRef>(v_bytes.as_ref())?;
+ if Some(&block_ref.block) == last_hash.as_ref() {
+ continue;
+ }
+ if !block_ref.deleted {
+ last_hash = Some(block_ref.block);
+ self.put_to_resync(&block_ref.block, 0)?;
+ }
+ i += 1;
+ if i & 0xFF == 0 && *must_exit.borrow() {
+ return Ok(());
+ }
+ }
+
+ // 2. Repair blocks actually on disk
+ let mut ls_data_dir = fs::read_dir(&self.data_dir).await?;
+ while let Some(data_dir_ent) = ls_data_dir.next().await {
+ let data_dir_ent = data_dir_ent?;
+ let dir_name = data_dir_ent.file_name();
+ let dir_name = match dir_name.into_string() {
+ Ok(x) => x,
+ Err(_) => continue,
+ };
+ if dir_name.len() != 2 || hex::decode(&dir_name).is_err() {
+ continue;
+ }
+
+ let mut ls_data_dir_2 = match fs::read_dir(data_dir_ent.path()).await {
+ Err(e) => {
+ warn!(
+ "Warning: could not list dir {:?}: {}",
+ data_dir_ent.path().to_str(),
+ e
+ );
+ continue;
+ }
+ Ok(x) => x,
+ };
+ while let Some(file) = ls_data_dir_2.next().await {
+ let file = file?;
+ let file_name = file.file_name();
+ let file_name = match file_name.into_string() {
+ Ok(x) => x,
+ Err(_) => continue,
+ };
+ if file_name.len() != 64 {
+ continue;
+ }
+ let hash_bytes = match hex::decode(&file_name) {
+ Ok(h) => h,
+ Err(_) => continue,
+ };
+ let mut hash = [0u8; 32];
+ hash.copy_from_slice(&hash_bytes[..]);
+ self.put_to_resync(&hash.into(), 0)?;
+
+ if *must_exit.borrow() {
+ return Ok(());
+ }
+ }
+ }
+ Ok(())
+ }
+}
+
+fn u64_from_bytes(bytes: &[u8]) -> u64 {
+ assert!(bytes.len() == 8);
+ let mut x8 = [0u8; 8];
+ x8.copy_from_slice(bytes);
+ u64::from_be_bytes(x8)
+}
+
+fn rc_merge(_key: &[u8], old: Option<&[u8]>, new: &[u8]) -> Option<Vec<u8>> {
+ let old = old.map(u64_from_bytes).unwrap_or(0);
+ assert!(new.len() == 1);
+ let new = match new[0] {
+ 0 => {
+ if old > 0 {
+ old - 1
+ } else {
+ 0
+ }
+ }
+ 1 => old + 1,
+ _ => unreachable!(),
+ };
+ if new == 0 {
+ None
+ } else {
+ Some(u64::to_be_bytes(new).to_vec())
+ }
+}