use std::convert::TryInto; use std::path::PathBuf; use std::sync::Arc; use std::time::Duration; use arc_swap::{ArcSwap, ArcSwapOption}; use async_trait::async_trait; use bytes::Bytes; use rand::prelude::*; use serde::{Deserialize, Serialize}; use tokio::fs; use tokio::io::{AsyncReadExt, AsyncWriteExt, BufReader}; use tokio::sync::{mpsc, Mutex, MutexGuard, Semaphore}; use opentelemetry::{ trace::{FutureExt as OtelFutureExt, TraceContextExt, Tracer}, Context, }; use garage_net::stream::{read_stream_to_end, stream_asyncread, ByteStream}; use garage_db as db; use garage_util::background::{vars, BackgroundRunner}; use garage_util::config::Config; use garage_util::data::*; use garage_util::error::*; use garage_util::metrics::RecordDuration; use garage_util::persister::{Persister, PersisterShared}; use garage_util::time::msec_to_rfc3339; use garage_rpc::rpc_helper::OrderTag; use garage_rpc::system::System; use garage_rpc::*; use garage_table::replication::{TableReplication, TableShardedReplication}; use crate::block::*; use crate::layout::*; use crate::metrics::*; use crate::rc::*; use crate::repair::*; use crate::resync::*; /// Size under which data will be stored inlined in database instead of as files pub const INLINE_THRESHOLD: usize = 3072; // The delay between the moment when the reference counter // drops to zero, and the moment where we allow ourselves // to delete the block locally. pub(crate) const BLOCK_GC_DELAY: Duration = Duration::from_secs(600); /// RPC messages used to share blocks of data between nodes #[derive(Debug, Serialize, Deserialize)] pub enum BlockRpc { Ok, /// Message to ask for a block of data, by hash GetBlock(Hash, Option), /// Message to send a block of data, either because requested, of for first delivery of new /// block PutBlock { hash: Hash, header: DataBlockHeader, }, /// Ask other node if they should have this block, but don't actually have it NeedBlockQuery(Hash), /// Response : whether the node do require that block NeedBlockReply(bool), } impl Rpc for BlockRpc { type Response = Result; } /// The block manager, handling block exchange between nodes, and block storage on local node pub struct BlockManager { /// Replication strategy, allowing to find on which node blocks should be located pub replication: TableShardedReplication, /// Data layout pub(crate) data_layout: ArcSwap, /// Data layout persister pub(crate) data_layout_persister: Persister, data_fsync: bool, compression_level: Option, disable_scrub: bool, mutation_lock: Vec>, pub(crate) rc: BlockRc, pub resync: BlockResyncManager, pub(crate) system: Arc, pub(crate) endpoint: Arc>, buffer_kb_semaphore: Arc, pub(crate) metrics: BlockManagerMetrics, pub scrub_persister: PersisterShared, tx_scrub_command: ArcSwapOption>, } #[derive(Serialize, Deserialize, Clone, Debug)] pub struct BlockResyncErrorInfo { pub hash: Hash, pub refcount: u64, pub error_count: u64, pub last_try: u64, pub next_try: u64, } // The number of different mutexes used to parallelize write access to data blocks const MUTEX_COUNT: usize = 256; // This custom struct contains functions that must only be ran // when the lock is held. We ensure that it is the case by storing // it INSIDE a Mutex. struct BlockManagerLocked(); impl BlockManager { pub fn new( db: &db::Db, config: &Config, replication: TableShardedReplication, system: Arc, ) -> Result, Error> { // Load or compute layout, i.e. assignment of data blocks to the different data directories let data_layout_persister: Persister = Persister::new(&system.metadata_dir, "data_layout"); let mut data_layout = match data_layout_persister.load() { Ok(layout) => layout .update(&config.data_dir) .ok_or_message("invalid data_dir config")?, Err(_) => { DataLayout::initialize(&config.data_dir).ok_or_message("invalid data_dir config")? } }; data_layout.check_markers()?; data_layout_persister .save(&data_layout) .expect("cannot save data_layout"); // Open metadata tables let rc = db .open_tree("block_local_rc") .expect("Unable to open block_local_rc tree"); let rc = BlockRc::new(rc); let resync = BlockResyncManager::new(db, &system); let endpoint = system .netapp .endpoint("garage_block/manager.rs/Rpc".to_string()); let buffer_kb_semaphore = Arc::new(Semaphore::new(config.block_ram_buffer_max / 1024)); let metrics = BlockManagerMetrics::new( config.compression_level, rc.rc.clone(), resync.queue.clone(), resync.errors.clone(), buffer_kb_semaphore.clone(), ); let scrub_persister = PersisterShared::new(&system.metadata_dir, "scrub_info"); let block_manager = Arc::new(Self { replication, data_layout: ArcSwap::new(Arc::new(data_layout)), data_layout_persister, data_fsync: config.data_fsync, disable_scrub: config.disable_scrub, compression_level: config.compression_level, mutation_lock: vec![(); MUTEX_COUNT] .iter() .map(|_| Mutex::new(BlockManagerLocked())) .collect::>(), rc, resync, system, endpoint, buffer_kb_semaphore, metrics, scrub_persister, tx_scrub_command: ArcSwapOption::new(None), }); block_manager.endpoint.set_handler(block_manager.clone()); block_manager.scrub_persister.set_with(|_| ()).unwrap(); Ok(block_manager) } pub fn spawn_workers(self: &Arc, bg: &BackgroundRunner) { // Spawn a bunch of resync workers for index in 0..MAX_RESYNC_WORKERS { let worker = ResyncWorker::new(index, self.clone()); bg.spawn_worker(worker); } // Spawn scrub worker if !self.disable_scrub { let (scrub_tx, scrub_rx) = mpsc::channel(1); self.tx_scrub_command.store(Some(Arc::new(scrub_tx))); bg.spawn_worker(ScrubWorker::new( self.clone(), scrub_rx, self.scrub_persister.clone(), )); } } pub fn register_bg_vars(&self, vars: &mut vars::BgVars) { self.resync.register_bg_vars(vars); if !self.disable_scrub { vars.register_rw( &self.scrub_persister, "scrub-tranquility", |p| p.get_with(|x| x.tranquility), |p, tranquility| p.set_with(|x| x.tranquility = tranquility), ); vars.register_ro(&self.scrub_persister, "scrub-last-completed", |p| { p.get_with(|x| msec_to_rfc3339(x.time_last_complete_scrub)) }); vars.register_ro(&self.scrub_persister, "scrub-next-run", |p| { p.get_with(|x| msec_to_rfc3339(x.time_next_run_scrub)) }); vars.register_ro(&self.scrub_persister, "scrub-corruptions_detected", |p| { p.get_with(|x| x.corruptions_detected) }); } } /// Ask nodes that might have a (possibly compressed) block for it /// Return it as a stream with a header async fn rpc_get_raw_block_streaming( &self, hash: &Hash, order_tag: Option, ) -> Result { self.rpc_get_raw_block_internal(hash, order_tag, |stream| async move { Ok(stream) }) .await } /// Ask nodes that might have a (possibly compressed) block for it /// Return its entire body pub(crate) async fn rpc_get_raw_block( &self, hash: &Hash, order_tag: Option, ) -> Result { self.rpc_get_raw_block_internal(hash, order_tag, |block_stream| async move { let (header, stream) = block_stream.into_parts(); read_stream_to_end(stream) .await .err_context("error in block data stream") .map(|data| DataBlock::from_parts(header, data.into_bytes())) }) .await } async fn rpc_get_raw_block_internal( &self, hash: &Hash, order_tag: Option, f: F, ) -> Result where F: Fn(DataBlockStream) -> Fut, Fut: futures::Future>, { let who = self.replication.read_nodes(hash); let who = self.system.rpc.request_order(&who); for node in who.iter() { let node_id = NodeID::from(*node); let rpc = self.endpoint.call_streaming( &node_id, BlockRpc::GetBlock(*hash, order_tag), PRIO_NORMAL | PRIO_SECONDARY, ); tokio::select! { res = rpc => { let res = match res { Ok(res) => res, Err(e) => { debug!("Get block {:?}: node {:?} could not be contacted: {}", hash, node, e); continue; } }; let block_stream = match res.into_parts() { (Ok(BlockRpc::PutBlock { hash: _, header }), Some(stream)) => DataBlockStream::from_parts(header, stream), (Ok(_), _) => { debug!("Get block {:?}: node {:?} returned a malformed response", hash, node); continue; } (Err(e), _) => { debug!("Get block {:?}: node {:?} returned error: {}", hash, node, e); continue; } }; match f(block_stream).await { Ok(ret) => return Ok(ret), Err(e) => { debug!("Get block {:?}: error reading stream from node {:?}: {}", hash, node, e); } } } // TODO: sleep less long (fail early), initiate a second request earlier // if the first one doesn't succeed rapidly // TODO: keep first request running when initiating a new one and take the // one that finishes earlier _ = tokio::time::sleep(self.system.rpc.rpc_timeout()) => { debug!("Get block {:?}: node {:?} didn't return block in time, trying next.", hash, node); } }; } let msg = format!("Get block {:?}: no node returned a valid block", hash); debug!("{}", msg); Err(Error::Message(msg)) } // ---- Public interface ---- /// Ask nodes that might have a block for it, return it as a stream pub async fn rpc_get_block_streaming( &self, hash: &Hash, order_tag: Option, ) -> Result { let block_stream = self.rpc_get_raw_block_streaming(hash, order_tag).await?; let (header, stream) = block_stream.into_parts(); match header { DataBlockHeader::Plain => Ok(stream), DataBlockHeader::Compressed => { // Too many things, I hate it. let reader = stream_asyncread(stream); let reader = BufReader::new(reader); let reader = async_compression::tokio::bufread::ZstdDecoder::new(reader); Ok(Box::pin(tokio_util::io::ReaderStream::new(reader))) } } } /// Ask nodes that might have a block for it, return it as one big Bytes pub async fn rpc_get_block( &self, hash: &Hash, order_tag: Option, ) -> Result { let stream = self.rpc_get_block_streaming(hash, order_tag).await?; Ok(read_stream_to_end(stream).await?.into_bytes()) } /// Send block to nodes that should have it pub async fn rpc_put_block( &self, hash: Hash, data: Bytes, order_tag: Option, ) -> Result<(), Error> { let who = self.replication.write_nodes(&hash); let (header, bytes) = DataBlock::from_buffer(data, self.compression_level) .await .into_parts(); let permit = self .buffer_kb_semaphore .clone() .acquire_many_owned((bytes.len() / 1024).try_into().unwrap()) .await .ok_or_message("could not reserve space for buffer of data to send to remote nodes")?; let put_block_rpc = Req::new(BlockRpc::PutBlock { hash, header })?.with_stream_from_buffer(bytes); let put_block_rpc = if let Some(tag) = order_tag { put_block_rpc.with_order_tag(tag) } else { put_block_rpc }; self.system .rpc .try_call_many( &self.endpoint, &who[..], put_block_rpc, RequestStrategy::with_priority(PRIO_NORMAL | PRIO_SECONDARY) .with_drop_on_completion(permit) .with_quorum(self.replication.write_quorum()), ) .await?; Ok(()) } /// Get number of items in the refcount table pub fn rc_len(&self) -> Result { Ok(self.rc.rc.len()?) } /// Get number of items in the refcount table pub fn rc_fast_len(&self) -> Result, Error> { Ok(self.rc.rc.fast_len()?) } /// Send command to start/stop/manager scrub worker pub async fn send_scrub_command(&self, cmd: ScrubWorkerCommand) -> Result<(), Error> { let tx = self.tx_scrub_command.load(); let tx = tx.as_ref().ok_or_message("scrub worker is not running")?; tx.send(cmd).await.ok_or_message("send error")?; Ok(()) } /// Get the reference count of a block pub fn get_block_rc(&self, hash: &Hash) -> Result { Ok(self.rc.get_block_rc(hash)?.as_u64()) } /// List all resync errors pub fn list_resync_errors(&self) -> Result, Error> { let mut blocks = Vec::with_capacity(self.resync.errors.len()); for ent in self.resync.errors.iter()? { let (hash, cnt) = ent?; let cnt = ErrorCounter::decode(&cnt); blocks.push(BlockResyncErrorInfo { hash: Hash::try_from(&hash).unwrap(), refcount: 0, error_count: cnt.errors, last_try: cnt.last_try, next_try: cnt.next_try(), }); } for block in blocks.iter_mut() { block.refcount = self.get_block_rc(&block.hash)?; } Ok(blocks) } //// ----- Managing the reference counter ---- /// Increment the number of time a block is used, putting it to resynchronization if it is /// required, but not known pub fn block_incref( self: &Arc, tx: &mut db::Transaction, hash: Hash, ) -> db::TxOpResult<()> { if self.rc.block_incref(tx, &hash)? { // When the reference counter is incremented, there is // normally a node that is responsible for sending us the // data of the block. However that operation may fail, // so in all cases we add the block here to the todo list // to check later that it arrived correctly, and if not // we will fecth it from someone. let this = self.clone(); tokio::spawn(async move { if let Err(e) = this .resync .put_to_resync(&hash, 2 * this.system.rpc.rpc_timeout()) { error!("Block {:?} could not be put in resync queue: {}.", hash, e); } }); } Ok(()) } /// Decrement the number of time a block is used pub fn block_decref( self: &Arc, tx: &mut db::Transaction, hash: Hash, ) -> db::TxOpResult<()> { if self.rc.block_decref(tx, &hash)? { // When the RC is decremented, it might drop to zero, // indicating that we don't need the block. // There is a delay before we garbage collect it; // make sure that it is handled in the resync loop // after that delay has passed. let this = self.clone(); tokio::spawn(async move { if let Err(e) = this .resync .put_to_resync(&hash, BLOCK_GC_DELAY + Duration::from_secs(10)) { error!("Block {:?} could not be put in resync queue: {}.", hash, e); } }); } Ok(()) } // ---- Reading and writing blocks locally ---- async fn handle_put_block( &self, hash: Hash, header: DataBlockHeader, stream: Option, ) -> Result<(), Error> { let stream = stream.ok_or_message("missing stream")?; let bytes = read_stream_to_end(stream).await?.into_bytes(); let data = DataBlock::from_parts(header, bytes); self.write_block(&hash, &data).await } /// Write a block to disk pub(crate) async fn write_block(&self, hash: &Hash, data: &DataBlock) -> Result<(), Error> { let tracer = opentelemetry::global::tracer("garage"); self.lock_mutate(hash) .await .write_block(hash, data, self) .bound_record_duration(&self.metrics.block_write_duration) .with_context(Context::current_with_span( tracer.start("BlockManagerLocked::write_block"), )) .await?; Ok(()) } async fn handle_get_block(&self, hash: &Hash, order_tag: Option) -> Resp { let block = match self.read_block(hash).await { Ok(data) => data, Err(e) => return Resp::new(Err(e)), }; let (header, data) = block.into_parts(); let resp = Resp::new(Ok(BlockRpc::PutBlock { hash: *hash, header, })) .with_stream_from_buffer(data); if let Some(order_tag) = order_tag { resp.with_order_tag(order_tag) } else { resp } } /// Read block from disk, verifying it's integrity pub(crate) async fn read_block(&self, hash: &Hash) -> Result { let tracer = opentelemetry::global::tracer("garage"); async { match self.find_block(hash).await { Some(p) => self.read_block_from(hash, &p).await, None => { // Not found but maybe we should have had it ?? self.resync .put_to_resync(hash, 2 * self.system.rpc.rpc_timeout())?; return Err(Error::Message(format!( "block {:?} not found on node", hash ))); } } } .bound_record_duration(&self.metrics.block_read_duration) .with_context(Context::current_with_span( tracer.start("BlockManager::read_block"), )) .await } pub(crate) async fn read_block_from( &self, hash: &Hash, block_path: &DataBlockPath, ) -> Result { let (header, path) = block_path.as_parts_ref(); let mut f = fs::File::open(&path).await?; let mut data = vec![]; f.read_to_end(&mut data).await?; self.metrics.bytes_read.add(data.len() as u64); drop(f); let data = DataBlock::from_parts(header, data.into()); if data.verify(*hash).is_err() { self.metrics.corruption_counter.add(1); warn!( "Block {:?} is corrupted. Renaming to .corrupted and resyncing.", hash ); self.lock_mutate(hash) .await .move_block_to_corrupted(block_path) .await?; self.resync.put_to_resync(hash, Duration::from_millis(0))?; return Err(Error::CorruptData(*hash)); } Ok(data) } /// Check if this node should have a block, but don't actually have it async fn need_block(&self, hash: &Hash) -> Result { let rc = self.rc.get_block_rc(hash)?; let exists = self.find_block(hash).await.is_some(); Ok(rc.is_nonzero() && !exists) } /// Delete block if it is not needed anymore pub(crate) async fn delete_if_unneeded(&self, hash: &Hash) -> Result<(), Error> { self.lock_mutate(hash) .await .delete_if_unneeded(hash, self) .await } /// Find the path where a block is currently stored pub(crate) async fn find_block(&self, hash: &Hash) -> Option { let data_layout = self.data_layout.load_full(); let dirs = Some(data_layout.primary_block_dir(hash)) .into_iter() .chain(data_layout.secondary_block_dirs(hash)); let filename = hex::encode(hash.as_ref()); for dir in dirs { let mut path = dir; path.push(&filename); if self.compression_level.is_none() { // If compression is disabled on node - check for the raw block // first and then a compressed one (as compression may have been // previously enabled). if fs::metadata(&path).await.is_ok() { return Some(DataBlockPath::plain(path)); } path.set_extension("zst"); if fs::metadata(&path).await.is_ok() { return Some(DataBlockPath::compressed(path)); } } else { path.set_extension("zst"); if fs::metadata(&path).await.is_ok() { return Some(DataBlockPath::compressed(path)); } path.set_extension(""); if fs::metadata(&path).await.is_ok() { return Some(DataBlockPath::plain(path)); } } } None } /// Rewrite a block at the primary location for its path and delete the old path. /// Returns the number of bytes read/written pub(crate) async fn fix_block_location( &self, hash: &Hash, wrong_path: DataBlockPath, ) -> Result { self.lock_mutate(hash) .await .fix_block_location(hash, wrong_path, self) .await } async fn lock_mutate(&self, hash: &Hash) -> MutexGuard<'_, BlockManagerLocked> { let tracer = opentelemetry::global::tracer("garage"); let ilock = u16::from_be_bytes([hash.as_slice()[0], hash.as_slice()[1]]) as usize % self.mutation_lock.len(); self.mutation_lock[ilock] .lock() .with_context(Context::current_with_span( tracer.start(format!("Acquire mutation_lock #{}", ilock)), )) .await } } #[async_trait] impl StreamingEndpointHandler for BlockManager { async fn handle(self: &Arc, mut message: Req, _from: NodeID) -> Resp { match message.msg() { BlockRpc::PutBlock { hash, header } => Resp::new( self.handle_put_block(*hash, *header, message.take_stream()) .await .map(|()| BlockRpc::Ok), ), BlockRpc::GetBlock(h, order_tag) => self.handle_get_block(h, *order_tag).await, BlockRpc::NeedBlockQuery(h) => { Resp::new(self.need_block(h).await.map(BlockRpc::NeedBlockReply)) } m => Resp::new(Err(Error::unexpected_rpc_message(m))), } } } impl BlockManagerLocked { async fn write_block( &self, hash: &Hash, data: &DataBlock, mgr: &BlockManager, ) -> Result<(), Error> { let existing_path = mgr.find_block(hash).await; self.write_block_inner(hash, data, mgr, existing_path).await } async fn write_block_inner( &self, hash: &Hash, data: &DataBlock, mgr: &BlockManager, existing_path: Option, ) -> Result<(), Error> { let (header, data) = data.as_parts_ref(); let compressed = header.is_compressed(); let directory = mgr.data_layout.load().primary_block_dir(hash); let mut tgt_path = directory.clone(); tgt_path.push(hex::encode(hash)); if compressed { tgt_path.set_extension("zst"); } let existing_info = existing_path.map(|x| x.into_parts()); let to_delete = match (existing_info, compressed) { // If the block is stored in the wrong directory, // write it again at the correct path and delete the old path (Some((DataBlockHeader::Plain, p)), false) if p != tgt_path => Some(p), (Some((DataBlockHeader::Compressed, p)), true) if p != tgt_path => Some(p), // If the block is already stored not compressed but we have a compressed // copy, write the compressed copy and delete the uncompressed one (Some((DataBlockHeader::Plain, plain_path)), true) => Some(plain_path), // If the block is already stored compressed, // keep the stored copy, we have nothing to do (Some((DataBlockHeader::Compressed, _)), _) => return Ok(()), // If the block is already stored not compressed, // and we don't have a compressed copy either, // keep the stored copy, we have nothing to do (Some((DataBlockHeader::Plain, _)), false) => return Ok(()), // If the block isn't stored already, just store what is given to us (None, _) => None, }; assert!(to_delete.as_ref() != Some(&tgt_path)); let mut path_tmp = tgt_path.clone(); let tmp_extension = format!("tmp{}", hex::encode(thread_rng().gen::<[u8; 4]>())); path_tmp.set_extension(tmp_extension); fs::create_dir_all(&directory).await?; let mut delete_on_drop = DeleteOnDrop(Some(path_tmp.clone())); let mut f = fs::File::create(&path_tmp).await?; f.write_all(data).await?; mgr.metrics.bytes_written.add(data.len() as u64); if mgr.data_fsync { f.sync_all().await?; } drop(f); fs::rename(path_tmp, tgt_path).await?; delete_on_drop.cancel(); if let Some(to_delete) = to_delete { fs::remove_file(to_delete).await?; } if mgr.data_fsync { // We want to ensure that when this function returns, data is properly persisted // to disk. The first step is the sync_all above that does an fsync on the data file. // Now, we do an fsync on the containing directory, to ensure that the rename // is persisted properly. See: // http://thedjbway.b0llix.net/qmail/syncdir.html let dir = fs::OpenOptions::new() .read(true) .mode(0) .open(directory) .await?; dir.sync_all().await?; drop(dir); } Ok(()) } async fn move_block_to_corrupted(&self, block_path: &DataBlockPath) -> Result<(), Error> { let (header, path) = block_path.as_parts_ref(); let mut path2 = path.clone(); if header.is_compressed() { path2.set_extension("zst.corrupted"); } else { path2.set_extension("corrupted"); } fs::rename(path, path2).await?; Ok(()) } async fn delete_if_unneeded(&self, hash: &Hash, mgr: &BlockManager) -> Result<(), Error> { let rc = mgr.rc.get_block_rc(hash)?; if rc.is_deletable() { while let Some(path) = mgr.find_block(hash).await { let (_header, path) = path.as_parts_ref(); fs::remove_file(path).await?; mgr.metrics.delete_counter.add(1); } } Ok(()) } async fn fix_block_location( &self, hash: &Hash, wrong_path: DataBlockPath, mgr: &BlockManager, ) -> Result { let data = mgr.read_block_from(hash, &wrong_path).await?; self.write_block_inner(hash, &data, mgr, Some(wrong_path)) .await?; Ok(data.as_parts_ref().1.len()) } } struct DeleteOnDrop(Option); impl DeleteOnDrop { fn cancel(&mut self) { drop(self.0.take()); } } impl Drop for DeleteOnDrop { fn drop(&mut self) { if let Some(path) = self.0.take() { tokio::spawn(async move { if let Err(e) = fs::remove_file(&path).await { debug!("DeleteOnDrop failed for {}: {}", path.display(), e); } }); } } }