use std::collections::HashMap; use std::sync::{atomic::Ordering, Arc, Mutex, RwLock, RwLockReadGuard}; use std::time::Duration; use tokio::sync::Notify; use garage_net::endpoint::Endpoint; use garage_net::peering::PeeringManager; use garage_net::NodeID; use garage_util::config::Config; use garage_util::data::*; use garage_util::error::*; use garage_util::persister::Persister; use super::*; use crate::replication_mode::*; use crate::rpc_helper::*; use crate::system::*; pub struct LayoutManager { node_id: Uuid, replication_factor: ReplicationFactor, persist_cluster_layout: Persister, layout: Arc>, pub(crate) change_notify: Arc, table_sync_version: Mutex>, pub(crate) rpc_helper: RpcHelper, system_endpoint: Arc>, } impl LayoutManager { pub fn new( config: &Config, node_id: NodeID, system_endpoint: Arc>, peering: Arc, replication_factor: ReplicationFactor, consistency_mode: ConsistencyMode, ) -> Result, Error> { let persist_cluster_layout: Persister = Persister::new(&config.metadata_dir, "cluster_layout"); let cluster_layout = match persist_cluster_layout.load() { Ok(x) => { if x.current().replication_factor != replication_factor.replication_factor() { return Err(Error::Message(format!( "Prevous cluster layout has replication factor {}, which is different than the one specified in the config file ({}). The previous cluster layout can be purged, if you know what you are doing, simply by deleting the `cluster_layout` file in your metadata directory.", x.current().replication_factor, replication_factor.replication_factor() ))); } x } Err(e) => { info!( "No valid previous cluster layout stored ({}), starting fresh.", e ); LayoutHistory::new(replication_factor) } }; let mut cluster_layout = LayoutHelper::new( replication_factor, consistency_mode, cluster_layout, Default::default(), ); cluster_layout.update_trackers(node_id.into()); let layout = Arc::new(RwLock::new(cluster_layout)); let change_notify = Arc::new(Notify::new()); let rpc_helper = RpcHelper::new( node_id.into(), peering, layout.clone(), config.rpc_timeout_msec.map(Duration::from_millis), ); Ok(Arc::new(Self { node_id: node_id.into(), replication_factor, persist_cluster_layout, layout, change_notify, table_sync_version: Mutex::new(HashMap::new()), system_endpoint, rpc_helper, })) } // ---- PUBLIC INTERFACE ---- pub fn layout(&self) -> RwLockReadGuard<'_, LayoutHelper> { self.layout.read().unwrap() } pub async fn update_cluster_layout( self: &Arc, layout: &LayoutHistory, ) -> Result<(), Error> { self.handle_advertise_cluster_layout(layout).await?; Ok(()) } pub fn add_table(&self, table_name: &'static str) { let first_version = self.layout().versions.first().unwrap().version; self.table_sync_version .lock() .unwrap() .insert(table_name.to_string(), first_version); } pub fn sync_table_until(self: &Arc, table_name: &'static str, version: u64) { let mut table_sync_version = self.table_sync_version.lock().unwrap(); *table_sync_version.get_mut(table_name).unwrap() = version; let sync_until = table_sync_version.iter().map(|(_, v)| *v).min().unwrap(); drop(table_sync_version); let mut layout = self.layout.write().unwrap(); if layout.update(|l| l.update_trackers.sync_map.set_max(self.node_id, sync_until)) { info!("sync_until updated to {}", sync_until); self.broadcast_update(SystemRpc::AdvertiseClusterLayoutTrackers( layout.update_trackers.clone(), )); } } fn ack_new_version(self: &Arc) { let mut layout = self.layout.write().unwrap(); if layout.ack_max_free(self.node_id) { self.broadcast_update(SystemRpc::AdvertiseClusterLayoutTrackers( layout.update_trackers.clone(), )); } } // ---- ACK LOCKING ---- pub fn write_sets_of(self: &Arc, position: &Hash) -> WriteLock>> { let layout = self.layout(); let version = layout.current().version; let nodes = layout.storage_sets_of(position); layout .ack_lock .get(&version) .unwrap() .fetch_add(1, Ordering::Relaxed); WriteLock::new(version, self, nodes) } // ---- INTERNALS --- fn merge_layout(&self, adv: &LayoutHistory) -> Option { let mut layout = self.layout.write().unwrap(); let prev_digest = layout.digest(); let prev_layout_check = layout.check().is_ok(); if !prev_layout_check || adv.check().is_ok() { if layout.update(|l| l.merge(adv)) { layout.update_trackers(self.node_id); if prev_layout_check && layout.check().is_err() { panic!("Merged two correct layouts and got an incorrect layout."); } assert!(layout.digest() != prev_digest); return Some(layout.clone()); } } None } fn merge_layout_trackers(&self, adv: &UpdateTrackers) -> Option { let mut layout = self.layout.write().unwrap(); let prev_digest = layout.digest(); if layout.update_trackers != *adv { if layout.update(|l| l.update_trackers.merge(adv)) { layout.update_trackers(self.node_id); assert!(layout.digest() != prev_digest); return Some(layout.update_trackers.clone()); } } None } async fn pull_cluster_layout(self: &Arc, peer: Uuid) { let resp = self .rpc_helper .call( &self.system_endpoint, peer, SystemRpc::PullClusterLayout, RequestStrategy::with_priority(PRIO_HIGH), ) .await; if let Ok(SystemRpc::AdvertiseClusterLayout(layout)) = resp { if let Err(e) = self.handle_advertise_cluster_layout(&layout).await { warn!("In pull_cluster_layout: {}", e); } } } async fn pull_cluster_layout_trackers(self: &Arc, peer: Uuid) { let resp = self .rpc_helper .call( &self.system_endpoint, peer, SystemRpc::PullClusterLayoutTrackers, RequestStrategy::with_priority(PRIO_HIGH), ) .await; if let Ok(SystemRpc::AdvertiseClusterLayoutTrackers(trackers)) = resp { if let Err(e) = self .handle_advertise_cluster_layout_trackers(&trackers) .await { warn!("In pull_cluster_layout_trackers: {}", e); } } } /// Save cluster layout data to disk async fn save_cluster_layout(&self) -> Result<(), Error> { let layout = self.layout.read().unwrap().clone(); self.persist_cluster_layout .save_async(&layout) .await .expect("Cannot save current cluster layout"); Ok(()) } fn broadcast_update(self: &Arc, rpc: SystemRpc) { tokio::spawn({ let this = self.clone(); async move { if let Err(e) = this .rpc_helper .broadcast( &this.system_endpoint, rpc, RequestStrategy::with_priority(PRIO_HIGH), ) .await { warn!("Error while broadcasting new cluster layout: {}", e); } } }); } // ---- RPC HANDLERS ---- pub(crate) fn handle_advertise_status(self: &Arc, from: Uuid, remote: &RpcLayoutDigest) { let local = self.layout().digest(); if remote.current_version > local.current_version || remote.active_versions != local.active_versions || remote.staging_hash != local.staging_hash { tokio::spawn({ let this = self.clone(); async move { this.pull_cluster_layout(from).await } }); } else if remote.trackers_hash != local.trackers_hash { tokio::spawn({ let this = self.clone(); async move { this.pull_cluster_layout_trackers(from).await } }); } } pub(crate) fn handle_pull_cluster_layout(&self) -> SystemRpc { let layout = self.layout.read().unwrap().clone(); SystemRpc::AdvertiseClusterLayout(layout) } pub(crate) fn handle_pull_cluster_layout_trackers(&self) -> SystemRpc { let layout = self.layout.read().unwrap(); SystemRpc::AdvertiseClusterLayoutTrackers(layout.update_trackers.clone()) } pub(crate) async fn handle_advertise_cluster_layout( self: &Arc, adv: &LayoutHistory, ) -> Result { debug!( "handle_advertise_cluster_layout: {} versions, last={}, trackers={:?}", adv.versions.len(), adv.current().version, adv.update_trackers ); if adv.current().replication_factor != self.replication_factor.replication_factor() { let msg = format!( "Received a cluster layout from another node with replication factor {}, which is different from what we have in our configuration ({}). Discarding the cluster layout we received.", adv.current().replication_factor, self.replication_factor.replication_factor() ); error!("{}", msg); return Err(Error::Message(msg)); } if let Some(new_layout) = self.merge_layout(adv) { debug!("handle_advertise_cluster_layout: some changes were added to the current stuff"); self.change_notify.notify_waiters(); self.broadcast_update(SystemRpc::AdvertiseClusterLayout(new_layout)); self.save_cluster_layout().await?; } Ok(SystemRpc::Ok) } pub(crate) async fn handle_advertise_cluster_layout_trackers( self: &Arc, trackers: &UpdateTrackers, ) -> Result { debug!("handle_advertise_cluster_layout_trackers: {:?}", trackers); if let Some(new_trackers) = self.merge_layout_trackers(trackers) { self.change_notify.notify_waiters(); self.broadcast_update(SystemRpc::AdvertiseClusterLayoutTrackers(new_trackers)); self.save_cluster_layout().await?; } Ok(SystemRpc::Ok) } } // ---- ack lock ---- pub struct WriteLock { layout_version: u64, layout_manager: Arc, value: T, } impl WriteLock { fn new(version: u64, layout_manager: &Arc, value: T) -> Self { Self { layout_version: version, layout_manager: layout_manager.clone(), value, } } } impl AsRef for WriteLock { fn as_ref(&self) -> &T { &self.value } } impl AsMut for WriteLock { fn as_mut(&mut self) -> &mut T { &mut self.value } } impl Drop for WriteLock { fn drop(&mut self) { let layout = self.layout_manager.layout(); // acquire read lock if let Some(counter) = layout.ack_lock.get(&self.layout_version) { let prev_lock = counter.fetch_sub(1, Ordering::Relaxed); if prev_lock == 1 && layout.current().version > self.layout_version { drop(layout); // release read lock, write lock will be acquired self.layout_manager.ack_new_version(); } } else { error!("Could not find ack lock counter for layout version {}. This probably indicates a bug in Garage.", self.layout_version); } } }