diff options
Diffstat (limited to 'src/block')
| -rw-r--r-- | src/block/Cargo.toml | 38 | ||||
| -rw-r--r-- | src/block/lib.rs | 6 | ||||
| -rw-r--r-- | src/block/manager.rs | 1091 | ||||
| -rw-r--r-- | src/block/metrics.rs | 102 |
4 files changed, 1237 insertions, 0 deletions
diff --git a/src/block/Cargo.toml b/src/block/Cargo.toml new file mode 100644 index 00000000..9cba69ee --- /dev/null +++ b/src/block/Cargo.toml @@ -0,0 +1,38 @@ +[package] +name = "garage_block" +version = "0.7.0" +authors = ["Alex Auvolat <alex@adnab.me>"] +edition = "2018" +license = "AGPL-3.0" +description = "Block manager for the Garage object store" +repository = "https://git.deuxfleurs.fr/Deuxfleurs/garage" +readme = "../../README.md" + +[lib] +path = "lib.rs" + +# See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html + +[dependencies] +garage_rpc = { version = "0.7.0", path = "../rpc" } +garage_util = { version = "0.7.0", path = "../util" } +garage_table = { version = "0.7.0", path = "../table" } + +opentelemetry = "0.17" + +async-trait = "0.1.7" +bytes = "1.0" +hex = "0.4" +tracing = "0.1.30" +rand = "0.8" +zstd = { version = "0.9", default-features = false } + +sled = "0.34" + +rmp-serde = "0.15" +serde = { version = "1.0", default-features = false, features = ["derive", "rc"] } +serde_bytes = "0.11" + +futures = "0.3" +futures-util = "0.3" +tokio = { version = "1.0", default-features = false, features = ["rt", "rt-multi-thread", "io-util", "net", "time", "macros", "sync", "signal", "fs"] } diff --git a/src/block/lib.rs b/src/block/lib.rs new file mode 100644 index 00000000..47ff402d --- /dev/null +++ b/src/block/lib.rs @@ -0,0 +1,6 @@ +#[macro_use] +extern crate tracing; + +pub mod manager; + +mod metrics; diff --git a/src/block/manager.rs b/src/block/manager.rs new file mode 100644 index 00000000..f047e1d3 --- /dev/null +++ b/src/block/manager.rs @@ -0,0 +1,1091 @@ +use std::convert::TryInto; +use std::path::{Path, PathBuf}; +use std::sync::Arc; +use std::time::Duration; + +use async_trait::async_trait; +use serde::{Deserialize, Serialize}; +use zstd::stream::{decode_all as zstd_decode, Encoder}; + +use futures::future::*; +use futures::select; +use tokio::fs; +use tokio::io::{AsyncReadExt, AsyncWriteExt}; +use tokio::sync::{watch, Mutex, Notify}; + +use opentelemetry::{ + trace::{FutureExt as OtelFutureExt, TraceContextExt, Tracer}, + Context, KeyValue, +}; + +use garage_util::data::*; +use garage_util::error::*; +use garage_util::metrics::RecordDuration; +use garage_util::sled_counter::SledCountedTree; +use garage_util::time::*; +use garage_util::tranquilizer::Tranquilizer; + +use garage_rpc::system::System; +use garage_rpc::*; + +use garage_table::replication::{TableReplication, TableShardedReplication}; + +use crate::metrics::*; + +/// Size under which data will be stored inlined in database instead of as files +pub const INLINE_THRESHOLD: usize = 3072; + +pub const BACKGROUND_TRANQUILITY: u32 = 2; + +// Timeout for RPCs that read and write blocks to remote nodes +const BLOCK_RW_TIMEOUT: Duration = Duration::from_secs(30); +// Timeout for RPCs that ask other nodes whether they need a copy +// of a given block before we delete it locally +const NEED_BLOCK_QUERY_TIMEOUT: Duration = Duration::from_secs(5); + +// The delay between the time where a resync operation fails +// and the time when it is retried, with exponential backoff +// (multiplied by 2, 4, 8, 16, etc. for every consecutive failure). +const RESYNC_RETRY_DELAY: Duration = Duration::from_secs(60); + +// The delay between the moment when the reference counter +// drops to zero, and the moment where we allow ourselves +// to delete the block locally. +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), + /// Message to send a block of data, either because requested, of for first delivery of new + /// block + PutBlock { + hash: Hash, + data: DataBlock, + }, + /// 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), +} + +/// A possibly compressed block of data +#[derive(Debug, Serialize, Deserialize)] +pub enum DataBlock { + /// Uncompressed data + Plain(#[serde(with = "serde_bytes")] Vec<u8>), + /// Data compressed with zstd + Compressed(#[serde(with = "serde_bytes")] Vec<u8>), +} + +impl DataBlock { + /// Query whether this block is compressed + pub fn is_compressed(&self) -> bool { + matches!(self, DataBlock::Compressed(_)) + } + + /// Get the inner, possibly compressed buffer. You should probably use [`DataBlock::verify_get`] + /// instead + pub fn inner_buffer(&self) -> &[u8] { + use DataBlock::*; + let (Plain(ref res) | Compressed(ref res)) = self; + res + } + + /// Get the buffer, possibly decompressing it, and verify it's integrity. + /// For Plain block, data is compared to hash, for Compressed block, zstd checksumming system + /// is used instead. + pub fn verify_get(self, hash: Hash) -> Result<Vec<u8>, Error> { + match self { + DataBlock::Plain(data) => { + if blake2sum(&data) == hash { + Ok(data) + } else { + Err(Error::CorruptData(hash)) + } + } + DataBlock::Compressed(data) => { + zstd_decode(&data[..]).map_err(|_| Error::CorruptData(hash)) + } + } + } + + /// Verify data integrity. Allocate less than [`DataBlock::verify_get`] and don't consume self, but + /// does not return the buffer content. + pub fn verify(&self, hash: Hash) -> Result<(), Error> { + match self { + DataBlock::Plain(data) => { + if blake2sum(data) == hash { + Ok(()) + } else { + Err(Error::CorruptData(hash)) + } + } + DataBlock::Compressed(data) => zstd::stream::copy_decode(&data[..], std::io::sink()) + .map_err(|_| Error::CorruptData(hash)), + } + } + + pub fn from_buffer(data: Vec<u8>, level: Option<i32>) -> DataBlock { + if let Some(level) = level { + if let Ok(data) = zstd_encode(&data[..], level) { + return DataBlock::Compressed(data); + } + } + DataBlock::Plain(data) + } +} + +impl Rpc for BlockRpc { + type Response = Result<BlockRpc, Error>; +} + +/// 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, + /// Directory in which block are stored + pub data_dir: PathBuf, + /// Zstd compression level + compression_level: Option<i32>, + + mutation_lock: Mutex<BlockManagerLocked>, + + rc: sled::Tree, + + resync_queue: SledCountedTree, + resync_notify: Notify, + resync_errors: SledCountedTree, + + system: Arc<System>, + endpoint: Arc<Endpoint<BlockRpc, Self>>, + + metrics: BlockManagerMetrics, +} + +// 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: &sled::Db, + data_dir: PathBuf, + compression_level: Option<i32>, + replication: TableShardedReplication, + system: Arc<System>, + ) -> Arc<Self> { + let rc = db + .open_tree("block_local_rc") + .expect("Unable to open block_local_rc tree"); + + let resync_queue = db + .open_tree("block_local_resync_queue") + .expect("Unable to open block_local_resync_queue tree"); + let resync_queue = SledCountedTree::new(resync_queue); + + let resync_errors = db + .open_tree("block_local_resync_errors") + .expect("Unable to open block_local_resync_errors tree"); + let resync_errors = SledCountedTree::new(resync_errors); + + let endpoint = system + .netapp + .endpoint("garage_model/block.rs/Rpc".to_string()); + + let manager_locked = BlockManagerLocked(); + + let metrics = BlockManagerMetrics::new(resync_queue.clone(), resync_errors.clone()); + + let block_manager = Arc::new(Self { + replication, + data_dir, + compression_level, + mutation_lock: Mutex::new(manager_locked), + rc, + resync_queue, + resync_notify: Notify::new(), + resync_errors, + system, + endpoint, + metrics, + }); + block_manager.endpoint.set_handler(block_manager.clone()); + + block_manager + } + + /// Ask nodes that might have a (possibly compressed) block for it + async fn rpc_get_raw_block(&self, hash: &Hash) -> Result<DataBlock, Error> { + let who = self.replication.read_nodes(hash); + let resps = self + .system + .rpc + .try_call_many( + &self.endpoint, + &who[..], + BlockRpc::GetBlock(*hash), + RequestStrategy::with_priority(PRIO_NORMAL) + .with_quorum(1) + .with_timeout(BLOCK_RW_TIMEOUT) + .interrupt_after_quorum(true), + ) + .await?; + + for resp in resps { + if let BlockRpc::PutBlock { data, .. } = resp { + return Ok(data); + } + } + Err(Error::Message(format!( + "Unable to read block {:?}: no valid blocks returned", + hash + ))) + } + + // ---- Public interface ---- + + /// Ask nodes that might have a block for it + pub async fn rpc_get_block(&self, hash: &Hash) -> Result<Vec<u8>, Error> { + self.rpc_get_raw_block(hash).await?.verify_get(*hash) + } + + /// Send block to nodes that should have it + pub async fn rpc_put_block(&self, hash: Hash, data: Vec<u8>) -> Result<(), Error> { + let who = self.replication.write_nodes(&hash); + let data = DataBlock::from_buffer(data, self.compression_level); + self.system + .rpc + .try_call_many( + &self.endpoint, + &who[..], + BlockRpc::PutBlock { hash, data }, + RequestStrategy::with_priority(PRIO_NORMAL) + .with_quorum(self.replication.write_quorum()) + .with_timeout(BLOCK_RW_TIMEOUT), + ) + .await?; + Ok(()) + } + + /// Launch the repair procedure on the data store + /// + /// This will list all blocks locally present, as well as those + /// that are required because of refcount > 0, and will try + /// to fix any mismatch between the two. + pub async fn repair_data_store(&self, must_exit: &watch::Receiver<bool>) -> Result<(), Error> { + // 1. Repair blocks from RC table. + for (i, entry) in self.rc.iter().enumerate() { + let (hash, _) = entry?; + let hash = Hash::try_from(&hash[..]).unwrap(); + self.put_to_resync(&hash, Duration::from_secs(0))?; + if i & 0xFF == 0 && *must_exit.borrow() { + return Ok(()); + } + } + + // 2. Repair blocks actually on disk + // Lists all blocks on disk and adds them to the resync queue. + // This allows us to find blocks we are storing but don't actually need, + // so that we can offload them if necessary and then delete them locally. + self.for_each_file( + (), + move |_, hash| async move { self.put_to_resync(&hash, Duration::from_secs(0)) }, + must_exit, + ) + .await + } + + /// Verify integrity of each block on disk. Use `speed_limit` to limit the load generated by + /// this function. + pub async fn scrub_data_store( + &self, + must_exit: &watch::Receiver<bool>, + tranquility: u32, + ) -> Result<(), Error> { + let tranquilizer = Tranquilizer::new(30); + self.for_each_file( + tranquilizer, + move |mut tranquilizer, hash| async move { + let _ = self.read_block(&hash).await; + tranquilizer.tranquilize(tranquility).await; + Ok(tranquilizer) + }, + must_exit, + ) + .await + } + + /// Get lenght of resync queue + pub fn resync_queue_len(&self) -> usize { + self.resync_queue.len() + } + + /// Get number of items in the refcount table + pub fn rc_len(&self) -> usize { + self.rc.len() + } + + //// ----- 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, hash: &Hash) -> Result<(), Error> { + let old_rc = self + .rc + .fetch_and_update(&hash, |old| RcEntry::parse_opt(old).increment().serialize())?; + let old_rc = RcEntry::parse_opt(old_rc); + if old_rc.is_zero() { + // 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. + self.put_to_resync(hash, 2 * BLOCK_RW_TIMEOUT)?; + } + Ok(()) + } + + /// Decrement the number of time a block is used + pub fn block_decref(&self, hash: &Hash) -> Result<(), Error> { + let new_rc = self + .rc + .update_and_fetch(&hash, |old| RcEntry::parse_opt(old).decrement().serialize())?; + let new_rc = RcEntry::parse_opt(new_rc); + if let RcEntry::Deletable { .. } = new_rc { + self.put_to_resync(hash, BLOCK_GC_DELAY + Duration::from_secs(10))?; + } + Ok(()) + } + + /// Read a block's reference count + fn get_block_rc(&self, hash: &Hash) -> Result<RcEntry, Error> { + Ok(RcEntry::parse_opt(self.rc.get(hash.as_ref())?)) + } + + /// Delete an entry in the RC table if it is deletable and the + /// deletion time has passed + fn clear_deleted_block_rc(&self, hash: &Hash) -> Result<(), Error> { + let now = now_msec(); + self.rc.update_and_fetch(&hash, |rcval| { + let updated = match RcEntry::parse_opt(rcval) { + RcEntry::Deletable { at_time } if now > at_time => RcEntry::Absent, + v => v, + }; + updated.serialize() + })?; + Ok(()) + } + + // ---- Reading and writing blocks locally ---- + + /// Write a block to disk + async fn write_block(&self, hash: &Hash, data: &DataBlock) -> Result<BlockRpc, Error> { + let write_size = data.inner_buffer().len() as u64; + + let res = self + .mutation_lock + .lock() + .await + .write_block(hash, data, self) + .bound_record_duration(&self.metrics.block_write_duration) + .await?; + + self.metrics.bytes_written.add(write_size); + + Ok(res) + } + + /// Read block from disk, verifying it's integrity + async fn read_block(&self, hash: &Hash) -> Result<BlockRpc, Error> { + let data = self + .read_block_internal(hash) + .bound_record_duration(&self.metrics.block_read_duration) + .await?; + + self.metrics + .bytes_read + .add(data.inner_buffer().len() as u64); + + Ok(BlockRpc::PutBlock { hash: *hash, data }) + } + + async fn read_block_internal(&self, hash: &Hash) -> Result<DataBlock, Error> { + let mut path = self.block_path(hash); + let compressed = match self.is_block_compressed(hash).await { + Ok(c) => c, + Err(e) => { + // Not found but maybe we should have had it ?? + self.put_to_resync(hash, 2 * BLOCK_RW_TIMEOUT)?; + return Err(Into::into(e)); + } + }; + if compressed { + path.set_extension("zst"); + } + let mut f = fs::File::open(&path).await?; + + let mut data = vec![]; + f.read_to_end(&mut data).await?; + drop(f); + + let data = if compressed { + DataBlock::Compressed(data) + } else { + DataBlock::Plain(data) + }; + + if data.verify(*hash).is_err() { + self.metrics.corruption_counter.add(1); + + self.mutation_lock + .lock() + .await + .move_block_to_corrupted(hash, self) + .await?; + self.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<bool, Error> { + let BlockStatus { exists, needed } = self + .mutation_lock + .lock() + .await + .check_block_status(hash, self) + .await?; + Ok(needed.is_nonzero() && !exists) + } + + /// Utility: gives the path of the directory in which a block should be found + 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 + } + + /// Utility: give the full path where a block should be found, minus extension if block is + /// compressed + fn block_path(&self, hash: &Hash) -> PathBuf { + let mut path = self.block_dir(hash); + path.push(hex::encode(hash.as_ref())); + path + } + + /// Utility: check if block is stored compressed. Error if block is not stored + async fn is_block_compressed(&self, hash: &Hash) -> Result<bool, Error> { + let mut path = self.block_path(hash); + path.set_extension("zst"); + if fs::metadata(&path).await.is_ok() { + return Ok(true); + } + path.set_extension(""); + fs::metadata(&path).await.map(|_| false).map_err(Into::into) + } + + // ---- Resync loop ---- + + pub fn spawn_background_worker(self: Arc<Self>) { + // Launch a background workers for background resync loop processing + let background = self.system.background.clone(); + tokio::spawn(async move { + tokio::time::sleep(Duration::from_secs(10)).await; + background.spawn_worker("block resync worker".into(), move |must_exit| { + self.resync_loop(must_exit) + }); + }); + } + + fn put_to_resync(&self, hash: &Hash, delay: Duration) -> Result<(), Error> { + let when = now_msec() + delay.as_millis() as u64; + self.put_to_resync_at(hash, when) + } + + fn put_to_resync_at(&self, hash: &Hash, when: u64) -> Result<(), Error> { + 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_waiters(); + Ok(()) + } + + async fn resync_loop(self: Arc<Self>, mut must_exit: watch::Receiver<bool>) { + let mut tranquilizer = Tranquilizer::new(30); + + while !*must_exit.borrow() { + match self.resync_iter(&mut must_exit).await { + Ok(true) => { + tranquilizer.tranquilize(BACKGROUND_TRANQUILITY).await; + } + Ok(false) => { + tranquilizer.reset(); + } + Err(e) => { + // The errors that we have here are only Sled errors + // We don't really know how to handle them so just ¯\_(ツ)_/¯ + // (there is kind of an assumption that Sled won't error on us, + // if it does there is not much we can do -- TODO should we just panic?) + error!( + "Could not do a resync iteration: {} (this is a very bad error)", + e + ); + tranquilizer.reset(); + } + } + } + } + + async fn resync_iter(&self, must_exit: &mut watch::Receiver<bool>) -> Result<bool, Error> { + if let Some(first_pair_res) = self.resync_queue.iter().next() { + let (time_bytes, hash_bytes) = first_pair_res?; + + let time_msec = u64::from_be_bytes(time_bytes[0..8].try_into().unwrap()); + let now = now_msec(); + + if now >= time_msec { + let hash = Hash::try_from(&hash_bytes[..]).unwrap(); + + if let Some(ec) = self.resync_errors.get(hash.as_slice())? { + let ec = ErrorCounter::decode(ec); + if now < ec.next_try() { + // if next retry after an error is not yet, + // don't do resync and return early, but still + // make sure the item is still in queue at expected time + self.put_to_resync_at(&hash, ec.next_try())?; + // ec.next_try() > now >= time_msec, so this remove + // is not removing the one we added just above + self.resync_queue.remove(time_bytes)?; + return Ok(false); + } + } + + let tracer = opentelemetry::global::tracer("garage"); + let trace_id = gen_uuid(); + let span = tracer + .span_builder("Resync block") + .with_trace_id( + opentelemetry::trace::TraceId::from_hex(&hex::encode( + &trace_id.as_slice()[..16], + )) + .unwrap(), + ) + .with_attributes(vec![KeyValue::new("block", format!("{:?}", hash))]) + .start(&tracer); + + let res = self + .resync_block(&hash) + .with_context(Context::current_with_span(span)) + .bound_record_duration(&self.metrics.resync_duration) + .await; + + self.metrics.resync_counter.add(1); + + if let Err(e) = &res { + self.metrics.resync_error_counter.add(1); + warn!("Error when resyncing {:?}: {}", hash, e); + + let err_counter = match self.resync_errors.get(hash.as_slice())? { + Some(ec) => ErrorCounter::decode(ec).add1(now + 1), + None => ErrorCounter::new(now + 1), + }; + + self.resync_errors + .insert(hash.as_slice(), err_counter.encode())?; + + self.put_to_resync_at(&hash, err_counter.next_try())?; + // err_counter.next_try() >= now + 1 > now, + // the entry we remove from the queue is not + // the entry we inserted with put_to_resync_at + self.resync_queue.remove(time_bytes)?; + } else { + self.resync_errors.remove(hash.as_slice())?; + self.resync_queue.remove(time_bytes)?; + } + + Ok(true) + } else { + let delay = tokio::time::sleep(Duration::from_millis(time_msec - now)); + select! { + _ = delay.fuse() => {}, + _ = self.resync_notify.notified().fuse() => {}, + _ = must_exit.changed().fuse() => {}, + } + Ok(false) + } + } else { + select! { + _ = self.resync_notify.notified().fuse() => {}, + _ = must_exit.changed().fuse() => {}, + } + Ok(false) + } + } + + async fn resync_block(&self, hash: &Hash) -> Result<(), Error> { + let BlockStatus { exists, needed } = self + .mutation_lock + .lock() + .await + .check_block_status(hash, self) + .await?; + + if exists != needed.is_needed() || exists != needed.is_nonzero() { + debug!( + "Resync block {:?}: exists {}, nonzero rc {}, deletable {}", + hash, + exists, + needed.is_nonzero(), + needed.is_deletable(), + ); + } + + if exists && needed.is_deletable() { + info!("Resync block {:?}: offloading and deleting", hash); + + let mut who = self.replication.write_nodes(hash); + if who.len() < self.replication.write_quorum() { + return Err(Error::Message("Not trying to offload block because we don't have a quorum of nodes to write to".to_string())); + } + who.retain(|id| *id != self.system.id); + + let msg = Arc::new(BlockRpc::NeedBlockQuery(*hash)); + let who_needs_fut = who.iter().map(|to| { + self.system.rpc.call_arc( + &self.endpoint, + *to, + msg.clone(), + RequestStrategy::with_priority(PRIO_BACKGROUND) + .with_timeout(NEED_BLOCK_QUERY_TIMEOUT), + ) + }); + let who_needs_resps = join_all(who_needs_fut).await; + + let mut need_nodes = vec![]; + for (node, needed) in who.iter().zip(who_needs_resps.into_iter()) { + match needed.err_context("NeedBlockQuery RPC")? { + BlockRpc::NeedBlockReply(needed) => { + if needed { + need_nodes.push(*node); + } + } + m => { + return Err(Error::unexpected_rpc_message(m)); + } + } + } + + if !need_nodes.is_empty() { + trace!( + "Block {:?} needed by {} nodes, sending", + hash, + need_nodes.len() + ); + + for node in need_nodes.iter() { + self.metrics + .resync_send_counter + .add(1, &[KeyValue::new("to", format!("{:?}", node))]); + } + + let put_block_message = self.read_block(hash).await?; + self.system + .rpc + .try_call_many( + &self.endpoint, + &need_nodes[..], + put_block_message, + RequestStrategy::with_priority(PRIO_BACKGROUND) + .with_quorum(need_nodes.len()) + .with_timeout(BLOCK_RW_TIMEOUT), + ) + .await + .err_context("PutBlock RPC")?; + } + info!( + "Deleting unneeded block {:?}, offload finished ({} / {})", + hash, + need_nodes.len(), + who.len() + ); + + self.mutation_lock + .lock() + .await + .delete_if_unneeded(hash, self) + .await?; + + self.clear_deleted_block_rc(hash)?; + } + + if needed.is_nonzero() && !exists { + info!( + "Resync block {:?}: fetching absent but needed block (refcount > 0)", + hash + ); + + let block_data = self.rpc_get_raw_block(hash).await?; + + self.metrics.resync_recv_counter.add(1); + + self.write_block(hash, &block_data).await?; + } + + Ok(()) + } + + // ---- Utility: iteration on files in the data directory ---- + + async fn for_each_file<F, Fut, State>( + &self, + state: State, + mut f: F, + must_exit: &watch::Receiver<bool>, + ) -> Result<(), Error> + where + F: FnMut(State, Hash) -> Fut + Send, + Fut: Future<Output = Result<State, Error>> + Send, + State: Send, + { + self.for_each_file_rec(&self.data_dir, state, &mut f, must_exit) + .await + .map(|_| ()) + } + + fn for_each_file_rec<'a, F, Fut, State>( + &'a self, + path: &'a Path, + mut state: State, + f: &'a mut F, + must_exit: &'a watch::Receiver<bool>, + ) -> BoxFuture<'a, Result<State, Error>> + where + F: FnMut(State, Hash) -> Fut + Send, + Fut: Future<Output = Result<State, Error>> + Send, + State: Send + 'a, + { + async move { + let mut ls_data_dir = fs::read_dir(path).await?; + while let Some(data_dir_ent) = ls_data_dir.next_entry().await? { + if *must_exit.borrow() { + break; + } + + let name = data_dir_ent.file_name(); + let name = if let Ok(n) = name.into_string() { + n + } else { + continue; + }; + let ent_type = data_dir_ent.file_type().await?; + + let name = name.strip_suffix(".zst").unwrap_or(&name); + if name.len() == 2 && hex::decode(&name).is_ok() && ent_type.is_dir() { + state = self + .for_each_file_rec(&data_dir_ent.path(), state, f, must_exit) + .await?; + } else if name.len() == 64 { + let hash_bytes = if let Ok(h) = hex::decode(&name) { + h + } else { + continue; + }; + let mut hash = [0u8; 32]; + hash.copy_from_slice(&hash_bytes[..]); + state = f(state, hash.into()).await?; + } + } + Ok(state) + } + .boxed() + } +} + +#[async_trait] +impl EndpointHandler<BlockRpc> for BlockManager { + async fn handle( + self: &Arc<Self>, + message: &BlockRpc, + _from: NodeID, + ) -> Result<BlockRpc, Error> { + match message { + BlockRpc::PutBlock { hash, data } => self.write_block(hash, data).await, + BlockRpc::GetBlock(h) => self.read_block(h).await, + BlockRpc::NeedBlockQuery(h) => self.need_block(h).await.map(BlockRpc::NeedBlockReply), + m => Err(Error::unexpected_rpc_message(m)), + } + } +} + +struct BlockStatus { + exists: bool, + needed: RcEntry, +} + +impl BlockManagerLocked { + async fn check_block_status( + &self, + hash: &Hash, + mgr: &BlockManager, + ) -> Result<BlockStatus, Error> { + let exists = mgr.is_block_compressed(hash).await.is_ok(); + let needed = mgr.get_block_rc(hash)?; + + Ok(BlockStatus { exists, needed }) + } + + async fn write_block( + &self, + hash: &Hash, + data: &DataBlock, + mgr: &BlockManager, + ) -> Result<BlockRpc, Error> { + let compressed = data.is_compressed(); + let data = data.inner_buffer(); + + let mut path = mgr.block_dir(hash); + let directory = path.clone(); + path.push(hex::encode(hash)); + + fs::create_dir_all(&directory).await?; + + let to_delete = match (mgr.is_block_compressed(hash).await, compressed) { + (Ok(true), _) => return Ok(BlockRpc::Ok), + (Ok(false), false) => return Ok(BlockRpc::Ok), + (Ok(false), true) => { + let path_to_delete = path.clone(); + path.set_extension("zst"); + Some(path_to_delete) + } + (Err(_), compressed) => { + if compressed { + path.set_extension("zst"); + } + None + } + }; + + let mut path2 = path.clone(); + path2.set_extension("tmp"); + let mut f = fs::File::create(&path2).await?; + f.write_all(data).await?; + f.sync_all().await?; + drop(f); + + fs::rename(path2, path).await?; + if let Some(to_delete) = to_delete { + fs::remove_file(to_delete).await?; + } + + // 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(BlockRpc::Ok) + } + + async fn move_block_to_corrupted(&self, hash: &Hash, mgr: &BlockManager) -> Result<(), Error> { + warn!( + "Block {:?} is corrupted. Renaming to .corrupted and resyncing.", + hash + ); + let mut path = mgr.block_path(hash); + let mut path2 = path.clone(); + if mgr.is_block_compressed(hash).await? { + path.set_extension("zst"); + 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 BlockStatus { exists, needed } = self.check_block_status(hash, mgr).await?; + + if exists && needed.is_deletable() { + let mut path = mgr.block_path(hash); + if mgr.is_block_compressed(hash).await? { + path.set_extension("zst"); + } + fs::remove_file(path).await?; + mgr.metrics.delete_counter.add(1); + } + Ok(()) + } +} + +/// Describes the state of the reference counter for a block +#[derive(Clone, Copy, Debug)] +enum RcEntry { + /// Present: the block has `count` references, with `count` > 0. + /// + /// This is stored as u64::to_be_bytes(count) + Present { count: u64 }, + + /// Deletable: the block has zero references, and can be deleted + /// once time (returned by now_msec) is larger than at_time + /// (in millis since Unix epoch) + /// + /// This is stored as [0u8; 8] followed by u64::to_be_bytes(at_time), + /// (this allows for the data format to be backwards compatible with + /// previous Garage versions that didn't have this intermediate state) + Deletable { at_time: u64 }, + + /// Absent: the block has zero references, and can be deleted + /// immediately + Absent, +} + +impl RcEntry { + fn parse(bytes: &[u8]) -> Self { + if bytes.len() == 8 { + RcEntry::Present { + count: u64::from_be_bytes(bytes.try_into().unwrap()), + } + } else if bytes.len() == 16 { + RcEntry::Deletable { + at_time: u64::from_be_bytes(bytes[8..16].try_into().unwrap()), + } + } else { + panic!("Invalid RC entry: {:?}, database is corrupted. This is an error Garage is currently unable to recover from. Sorry, and also please report a bug.", + bytes + ) + } + } + + fn parse_opt<V: AsRef<[u8]>>(bytes: Option<V>) -> Self { + bytes + .map(|b| Self::parse(b.as_ref())) + .unwrap_or(Self::Absent) + } + + fn serialize(self) -> Option<Vec<u8>> { + match self { + RcEntry::Present { count } => Some(u64::to_be_bytes(count).to_vec()), + RcEntry::Deletable { at_time } => { + Some([u64::to_be_bytes(0), u64::to_be_bytes(at_time)].concat()) + } + RcEntry::Absent => None, + } + } + + fn increment(self) -> Self { + let old_count = match self { + RcEntry::Present { count } => count, + _ => 0, + }; + RcEntry::Present { + count: old_count + 1, + } + } + + fn decrement(self) -> Self { + match self { + RcEntry::Present { count } => { + if count > 1 { + RcEntry::Present { count: count - 1 } + } else { + RcEntry::Deletable { + at_time: now_msec() + BLOCK_GC_DELAY.as_millis() as u64, + } + } + } + del => del, + } + } + + fn is_zero(&self) -> bool { + matches!(self, RcEntry::Deletable { .. } | RcEntry::Absent) + } + + fn is_nonzero(&self) -> bool { + !self.is_zero() + } + + fn is_deletable(&self) -> bool { + match self { + RcEntry::Present { .. } => false, + RcEntry::Deletable { at_time } => now_msec() > *at_time, + RcEntry::Absent => true, + } + } + + fn is_needed(&self) -> bool { + !self.is_deletable() + } +} + +/// Counts the number of errors when resyncing a block, +/// and the time of the last try. +/// Used to implement exponential backoff. +#[derive(Clone, Copy, Debug)] +struct ErrorCounter { + errors: u64, + last_try: u64, +} + +impl ErrorCounter { + fn new(now: u64) -> Self { + Self { + errors: 1, + last_try: now, + } + } + + fn decode(data: sled::IVec) -> Self { + Self { + errors: u64::from_be_bytes(data[0..8].try_into().unwrap()), + last_try: u64::from_be_bytes(data[8..16].try_into().unwrap()), + } + } + fn encode(&self) -> Vec<u8> { + [ + u64::to_be_bytes(self.errors), + u64::to_be_bytes(self.last_try), + ] + .concat() + } + + fn add1(self, now: u64) -> Self { + Self { + errors: self.errors + 1, + last_try: now, + } + } + + fn delay_msec(&self) -> u64 { + (RESYNC_RETRY_DELAY.as_millis() as u64) << std::cmp::min(self.errors - 1, 10) + } + fn next_try(&self) -> u64 { + self.last_try + self.delay_msec() + } +} + +fn zstd_encode<R: std::io::Read>(mut source: R, level: i32) -> std::io::Result<Vec<u8>> { + let mut result = Vec::<u8>::new(); + let mut encoder = Encoder::new(&mut result, level)?; + encoder.include_checksum(true)?; + std::io::copy(&mut source, &mut encoder)?; + encoder.finish()?; + Ok(result) +} diff --git a/src/block/metrics.rs b/src/block/metrics.rs new file mode 100644 index 00000000..f0f541a3 --- /dev/null +++ b/src/block/metrics.rs @@ -0,0 +1,102 @@ +use opentelemetry::{global, metrics::*}; + +use garage_util::sled_counter::SledCountedTree; + +/// TableMetrics reference all counter used for metrics +pub struct BlockManagerMetrics { + pub(crate) _resync_queue_len: ValueObserver<u64>, + pub(crate) _resync_errored_blocks: ValueObserver<u64>, + + pub(crate) resync_counter: BoundCounter<u64>, + pub(crate) resync_error_counter: BoundCounter<u64>, + pub(crate) resync_duration: BoundValueRecorder<f64>, + pub(crate) resync_send_counter: Counter<u64>, + pub(crate) resync_recv_counter: BoundCounter<u64>, + + pub(crate) bytes_read: BoundCounter<u64>, + pub(crate) block_read_duration: BoundValueRecorder<f64>, + pub(crate) bytes_written: BoundCounter<u64>, + pub(crate) block_write_duration: BoundValueRecorder<f64>, + pub(crate) delete_counter: BoundCounter<u64>, + + pub(crate) corruption_counter: BoundCounter<u64>, +} + +impl BlockManagerMetrics { + pub fn new(resync_queue: SledCountedTree, resync_errors: SledCountedTree) -> Self { + let meter = global::meter("garage_model/block"); + Self { + _resync_queue_len: meter + .u64_value_observer("block.resync_queue_length", move |observer| { + observer.observe(resync_queue.len() as u64, &[]) + }) + .with_description( + "Number of block hashes queued for local check and possible resync", + ) + .init(), + _resync_errored_blocks: meter + .u64_value_observer("block.resync_errored_blocks", move |observer| { + observer.observe(resync_errors.len() as u64, &[]) + }) + .with_description("Number of block hashes whose last resync resulted in an error") + .init(), + + resync_counter: meter + .u64_counter("block.resync_counter") + .with_description("Number of calls to resync_block") + .init() + .bind(&[]), + resync_error_counter: meter + .u64_counter("block.resync_error_counter") + .with_description("Number of calls to resync_block that returned an error") + .init() + .bind(&[]), + resync_duration: meter + .f64_value_recorder("block.resync_duration") + .with_description("Duration of resync_block operations") + .init() + .bind(&[]), + resync_send_counter: meter + .u64_counter("block.resync_send_counter") + .with_description("Number of blocks sent to another node in resync operations") + .init(), + resync_recv_counter: meter + .u64_counter("block.resync_recv_counter") + .with_description("Number of blocks received from other nodes in resync operations") + .init() + .bind(&[]), + + bytes_read: meter + .u64_counter("block.bytes_read") + .with_description("Number of bytes read from disk") + .init() + .bind(&[]), + block_read_duration: meter + .f64_value_recorder("block.read_duration") + .with_description("Duration of block read operations") + .init() + .bind(&[]), + bytes_written: meter + .u64_counter("block.bytes_written") + .with_description("Number of bytes written to disk") + .init() + .bind(&[]), + block_write_duration: meter + .f64_value_recorder("block.write_duration") + .with_description("Duration of block write operations") + .init() + .bind(&[]), + delete_counter: meter + .u64_counter("block.delete_counter") + .with_description("Number of blocks deleted") + .init() + .bind(&[]), + + corruption_counter: meter + .u64_counter("block.corruption_counter") + .with_description("Data corruptions detected on block reads") + .init() + .bind(&[]), + } + } +} |