use std::sync::{Arc, RwLock, RwLockReadGuard}; use std::time::Duration; use serde::{Deserialize, Serialize}; use tokio::sync::Notify; use netapp::endpoint::Endpoint; use netapp::peering::fullmesh::FullMeshPeeringStrategy; use netapp::NodeID; use garage_util::config::Config; use garage_util::data::*; use garage_util::error::*; use garage_util::persister::Persister; use super::*; use crate::rpc_helper::*; use crate::system::*; pub struct LayoutManager { node_id: Uuid, replication_factor: usize, persist_cluster_layout: Persister, layout: Arc>, pub(crate) change_notify: Arc, pub(crate) rpc_helper: RpcHelper, system_endpoint: Arc>, } #[derive(Debug, Clone, Serialize, Deserialize, Default)] pub struct LayoutStatus { /// Cluster layout version pub cluster_layout_version: u64, /// Hash of cluster layout update trackers pub cluster_layout_trackers_hash: Hash, /// Hash of cluster layout staging data pub cluster_layout_staging_hash: Hash, } impl LayoutManager { pub fn new( config: &Config, node_id: NodeID, system_endpoint: Arc>, fullmesh: Arc, replication_factor: usize, ) -> 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 { 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 ))); } x } Err(e) => { info!( "No valid previous cluster layout stored ({}), starting fresh.", e ); LayoutHistory::new(replication_factor) } }; let layout = Arc::new(RwLock::new(cluster_layout)); let change_notify = Arc::new(Notify::new()); let rpc_helper = RpcHelper::new( node_id.into(), fullmesh, 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, system_endpoint, rpc_helper, })) } // ---- PUBLIC INTERFACE ---- pub fn layout(&self) -> RwLockReadGuard<'_, LayoutHistory> { self.layout.read().unwrap() } pub fn status(&self) -> LayoutStatus { let layout = self.layout(); LayoutStatus { cluster_layout_version: layout.current().version, cluster_layout_trackers_hash: layout.trackers_hash, cluster_layout_staging_hash: layout.staging_hash, } } pub async fn update_cluster_layout( self: &Arc, layout: &LayoutHistory, ) -> Result<(), Error> { self.handle_advertise_cluster_layout(layout).await?; Ok(()) } // ---- INTERNALS --- fn merge_layout(&self, adv: &LayoutHistory) -> Option { let mut layout = self.layout.write().unwrap(); let prev_layout_check = layout.check().is_ok(); if !prev_layout_check || adv.check().is_ok() { if layout.merge(adv) { if prev_layout_check && layout.check().is_err() { panic!("Merged two correct layouts and got an incorrect layout."); } return Some(layout.clone()); } } None } fn merge_layout_trackers(&self, adv: &UpdateTrackers) -> Option { let mut layout = self.layout.write().unwrap(); if layout.update_trackers != *adv { if layout.update_trackers.merge(adv) { 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: &LayoutStatus) { let local = self.status(); if remote.cluster_layout_version > local.cluster_layout_version || remote.cluster_layout_staging_hash != local.cluster_layout_staging_hash { tokio::spawn({ let this = self.clone(); async move { this.pull_cluster_layout(from).await } }); } else if remote.cluster_layout_trackers_hash != local.cluster_layout_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(); // TODO: avoid cloning 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 { if adv.current().replication_factor != self.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 ); error!("{}", msg); return Err(Error::Message(msg)); } if let Some(new_layout) = self.merge_layout(adv) { 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 { 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) } }