diff --git a/src/rpc/layout/history.rs b/src/rpc/layout/history.rs index cef56647..050f5d0a 100644 --- a/src/rpc/layout/history.rs +++ b/src/rpc/layout/history.rs @@ -18,7 +18,7 @@ impl LayoutHistory { }; let mut ret = LayoutHistory { - versions: vec![version].into_boxed_slice().into(), + versions: vec![version], update_trackers: Default::default(), trackers_hash: [0u8; 32].into(), staging: Lww::raw(0, staging), @@ -211,6 +211,11 @@ To know the correct value of the new layout version, invoke `garage layout show` let msg = new_version.calculate_partition_assignment()?; self.versions.push(new_version); + if self.current().check().is_ok() { + while self.versions.first().unwrap().check().is_err() { + self.versions.remove(0); + } + } // Reset the staged layout changes self.staging.update(LayoutStaging { @@ -245,7 +250,7 @@ To know the correct value of the new layout version, invoke `garage layout show` version.check()?; } - // TODO: anythign more ? + // TODO: anything more ? Ok(()) } } diff --git a/src/rpc/layout/mod.rs b/src/rpc/layout/mod.rs index cd3764bc..577b32fb 100644 --- a/src/rpc/layout/mod.rs +++ b/src/rpc/layout/mod.rs @@ -3,6 +3,9 @@ mod history; mod schema; mod version; +#[cfg(test)] +mod test; + pub mod manager; // ---- re-exports ---- diff --git a/src/rpc/layout/test.rs b/src/rpc/layout/test.rs new file mode 100644 index 00000000..0ce090d2 --- /dev/null +++ b/src/rpc/layout/test.rs @@ -0,0 +1,159 @@ +use std::cmp::min; +use std::collections::HashMap; + +use garage_util::crdt::Crdt; +use garage_util::error::*; + +use crate::layout::*; + +// This function checks that the partition size S computed is at least better than the +// one given by a very naive algorithm. To do so, we try to run the naive algorithm +// assuming a partion size of S+1. If we succed, it means that the optimal assignment +// was not optimal. The naive algorithm is the following : +// - we compute the max number of partitions associated to every node, capped at the +// partition number. It gives the number of tokens of every node. +// - every zone has a number of tokens equal to the sum of the tokens of its nodes. +// - we cycle over the partitions and associate zone tokens while respecting the +// zone redundancy constraint. +// NOTE: the naive algorithm is not optimal. Counter example: +// take nb_partition = 3 ; replication_factor = 5; redundancy = 4; +// number of tokens by zone : (A, 4), (B,1), (C,4), (D, 4), (E, 2) +// With these parameters, the naive algo fails, whereas there is a solution: +// (A,A,C,D,E) , (A,B,C,D,D) (A,C,C,D,E) +fn check_against_naive(cl: &LayoutVersion) -> Result { + let over_size = cl.partition_size + 1; + let mut zone_token = HashMap::::new(); + + let (zones, zone_to_id) = cl.generate_nongateway_zone_ids()?; + + if zones.is_empty() { + return Ok(false); + } + + for z in zones.iter() { + zone_token.insert(z.clone(), 0); + } + for uuid in cl.nongateway_nodes() { + let z = cl.get_node_zone(&uuid)?; + let c = cl.get_node_capacity(&uuid)?; + zone_token.insert( + z.to_string(), + zone_token[z] + min(NB_PARTITIONS, (c / over_size) as usize), + ); + } + + // For every partition, we count the number of zone already associated and + // the name of the last zone associated + + let mut id_zone_token = vec![0; zones.len()]; + for (z, t) in zone_token.iter() { + id_zone_token[zone_to_id[z]] = *t; + } + + let mut nb_token = vec![0; NB_PARTITIONS]; + let mut last_zone = vec![zones.len(); NB_PARTITIONS]; + + let mut curr_zone = 0; + + let redundancy = cl.effective_zone_redundancy(); + + for replic in 0..cl.replication_factor { + for p in 0..NB_PARTITIONS { + while id_zone_token[curr_zone] == 0 + || (last_zone[p] == curr_zone + && redundancy - nb_token[p] <= cl.replication_factor - replic) + { + curr_zone += 1; + if curr_zone >= zones.len() { + return Ok(true); + } + } + id_zone_token[curr_zone] -= 1; + if last_zone[p] != curr_zone { + nb_token[p] += 1; + last_zone[p] = curr_zone; + } + } + } + + return Ok(false); +} + +fn show_msg(msg: &Message) { + for s in msg.iter() { + println!("{}", s); + } +} + +fn update_layout( + cl: &mut LayoutHistory, + node_capacity_vec: &[u64], + node_zone_vec: &[&'static str], + zone_redundancy: usize, +) { + let staging = cl.staging.get_mut(); + + for (i, (capacity, zone)) in node_capacity_vec + .iter() + .zip(node_zone_vec.iter()) + .enumerate() + { + let node_id = [i as u8; 32].into(); + + let update = staging.roles.update_mutator( + node_id, + NodeRoleV(Some(NodeRole { + zone: zone.to_string(), + capacity: Some(*capacity), + tags: (vec![]), + })), + ); + staging.roles.merge(&update); + } + staging.parameters.update(LayoutParameters { + zone_redundancy: ZoneRedundancy::AtLeast(zone_redundancy), + }); + + cl.update_hashes(); +} + +#[test] +fn test_assignment() { + let mut node_capacity_vec = vec![4000, 1000, 2000]; + let mut node_zone_vec = vec!["A", "B", "C"]; + + let mut cl = LayoutHistory::new(3); + update_layout(&mut cl, &node_capacity_vec, &node_zone_vec, 3); + let v = cl.current().version; + let (mut cl, msg) = cl.apply_staged_changes(Some(v + 1)).unwrap(); + show_msg(&msg); + assert_eq!(cl.check(), Ok(())); + assert!(check_against_naive(cl.current()).unwrap()); + + node_capacity_vec = vec![4000, 1000, 1000, 3000, 1000, 1000, 2000, 10000, 2000]; + node_zone_vec = vec!["A", "B", "C", "C", "C", "B", "G", "H", "I"]; + update_layout(&mut cl, &node_capacity_vec, &node_zone_vec, 2); + let v = cl.current().version; + let (mut cl, msg) = cl.apply_staged_changes(Some(v + 1)).unwrap(); + show_msg(&msg); + assert_eq!(cl.check(), Ok(())); + assert!(check_against_naive(cl.current()).unwrap()); + + node_capacity_vec = vec![4000, 1000, 2000, 7000, 1000, 1000, 2000, 10000, 2000]; + update_layout(&mut cl, &node_capacity_vec, &node_zone_vec, 3); + let v = cl.current().version; + let (mut cl, msg) = cl.apply_staged_changes(Some(v + 1)).unwrap(); + show_msg(&msg); + assert_eq!(cl.check(), Ok(())); + assert!(check_against_naive(cl.current()).unwrap()); + + node_capacity_vec = vec![ + 4000000, 4000000, 2000000, 7000000, 1000000, 9000000, 2000000, 10000, 2000000, + ]; + update_layout(&mut cl, &node_capacity_vec, &node_zone_vec, 1); + let v = cl.current().version; + let (cl, msg) = cl.apply_staged_changes(Some(v + 1)).unwrap(); + show_msg(&msg); + assert_eq!(cl.check(), Ok(())); + assert!(check_against_naive(cl.current()).unwrap()); +} diff --git a/src/rpc/layout/version.rs b/src/rpc/layout/version.rs index f45a3c35..ffbdf277 100644 --- a/src/rpc/layout/version.rs +++ b/src/rpc/layout/version.rs @@ -143,7 +143,7 @@ impl LayoutVersion { } /// Given a node uuids, this function returns the label of its zone - fn get_node_zone(&self, uuid: &Uuid) -> Result<&str, Error> { + pub(crate) fn get_node_zone(&self, uuid: &Uuid) -> Result<&str, Error> { match self.node_role(uuid) { Some(role) => Ok(&role.zone), _ => Err(Error::Message( @@ -162,7 +162,7 @@ impl LayoutVersion { } /// Returns the effective value of the zone_redundancy parameter - fn effective_zone_redundancy(&self) -> usize { + pub(crate) fn effective_zone_redundancy(&self) -> usize { match self.parameters.zone_redundancy { ZoneRedundancy::AtLeast(v) => v, ZoneRedundancy::Maximum => { @@ -472,7 +472,9 @@ impl LayoutVersion { /// This function generates ids for the zone of the nodes appearing in /// self.node_id_vec. - fn generate_nongateway_zone_ids(&self) -> Result<(Vec, HashMap), Error> { + pub(crate) fn generate_nongateway_zone_ids( + &self, + ) -> Result<(Vec, HashMap), Error> { let mut id_to_zone = Vec::::new(); let mut zone_to_id = HashMap::::new(); @@ -838,167 +840,3 @@ impl LayoutVersion { Ok(msg) } } - -// ==================================================================================== - -#[cfg(test)] -mod tests { - use super::{Error, *}; - use std::cmp::min; - - // This function checks that the partition size S computed is at least better than the - // one given by a very naive algorithm. To do so, we try to run the naive algorithm - // assuming a partion size of S+1. If we succed, it means that the optimal assignment - // was not optimal. The naive algorithm is the following : - // - we compute the max number of partitions associated to every node, capped at the - // partition number. It gives the number of tokens of every node. - // - every zone has a number of tokens equal to the sum of the tokens of its nodes. - // - we cycle over the partitions and associate zone tokens while respecting the - // zone redundancy constraint. - // NOTE: the naive algorithm is not optimal. Counter example: - // take nb_partition = 3 ; replication_factor = 5; redundancy = 4; - // number of tokens by zone : (A, 4), (B,1), (C,4), (D, 4), (E, 2) - // With these parameters, the naive algo fails, whereas there is a solution: - // (A,A,C,D,E) , (A,B,C,D,D) (A,C,C,D,E) - fn check_against_naive(cl: &LayoutVersion) -> Result { - let over_size = cl.partition_size + 1; - let mut zone_token = HashMap::::new(); - - let (zones, zone_to_id) = cl.generate_nongateway_zone_ids()?; - - if zones.is_empty() { - return Ok(false); - } - - for z in zones.iter() { - zone_token.insert(z.clone(), 0); - } - for uuid in cl.nongateway_nodes() { - let z = cl.get_node_zone(&uuid)?; - let c = cl.get_node_capacity(&uuid)?; - zone_token.insert( - z.clone(), - zone_token[&z] + min(NB_PARTITIONS, (c / over_size) as usize), - ); - } - - // For every partition, we count the number of zone already associated and - // the name of the last zone associated - - let mut id_zone_token = vec![0; zones.len()]; - for (z, t) in zone_token.iter() { - id_zone_token[zone_to_id[z]] = *t; - } - - let mut nb_token = vec![0; NB_PARTITIONS]; - let mut last_zone = vec![zones.len(); NB_PARTITIONS]; - - let mut curr_zone = 0; - - let redundancy = cl.effective_zone_redundancy(); - - for replic in 0..cl.replication_factor { - for p in 0..NB_PARTITIONS { - while id_zone_token[curr_zone] == 0 - || (last_zone[p] == curr_zone - && redundancy - nb_token[p] <= cl.replication_factor - replic) - { - curr_zone += 1; - if curr_zone >= zones.len() { - return Ok(true); - } - } - id_zone_token[curr_zone] -= 1; - if last_zone[p] != curr_zone { - nb_token[p] += 1; - last_zone[p] = curr_zone; - } - } - } - - return Ok(false); - } - - fn show_msg(msg: &Message) { - for s in msg.iter() { - println!("{}", s); - } - } - - fn update_layout( - cl: &mut LayoutVersion, - node_id_vec: &Vec, - node_capacity_vec: &Vec, - node_zone_vec: &Vec, - zone_redundancy: usize, - ) { - for i in 0..node_id_vec.len() { - if let Some(x) = FixedBytes32::try_from(&[i as u8; 32]) { - cl.node_id_vec.push(x); - } - - let update = cl.staging_roles.update_mutator( - cl.node_id_vec[i], - NodeRoleV(Some(NodeRole { - zone: (node_zone_vec[i].to_string()), - capacity: (Some(node_capacity_vec[i])), - tags: (vec![]), - })), - ); - cl.staging_roles.merge(&update); - } - cl.staging_parameters.update(LayoutParameters { - zone_redundancy: ZoneRedundancy::AtLeast(zone_redundancy), - }); - cl.staging_hash = cl.calculate_staging_hash(); - } - - #[test] - fn test_assignment() { - let mut node_id_vec = vec![1, 2, 3]; - let mut node_capacity_vec = vec![4000, 1000, 2000]; - let mut node_zone_vec = vec!["A", "B", "C"] - .into_iter() - .map(|x| x.to_string()) - .collect(); - - let mut cl = LayoutVersion::new(3); - update_layout(&mut cl, &node_id_vec, &node_capacity_vec, &node_zone_vec, 3); - let v = cl.version; - let (mut cl, msg) = cl.apply_staged_changes(Some(v + 1)).unwrap(); - show_msg(&msg); - assert_eq!(cl.check(), Ok(())); - assert!(matches!(check_against_naive(&cl), Ok(true))); - - node_id_vec = vec![1, 2, 3, 4, 5, 6, 7, 8, 9]; - node_capacity_vec = vec![4000, 1000, 1000, 3000, 1000, 1000, 2000, 10000, 2000]; - node_zone_vec = vec!["A", "B", "C", "C", "C", "B", "G", "H", "I"] - .into_iter() - .map(|x| x.to_string()) - .collect(); - update_layout(&mut cl, &node_id_vec, &node_capacity_vec, &node_zone_vec, 2); - let v = cl.version; - let (mut cl, msg) = cl.apply_staged_changes(Some(v + 1)).unwrap(); - show_msg(&msg); - assert_eq!(cl.check(), Ok(())); - assert!(matches!(check_against_naive(&cl), Ok(true))); - - node_capacity_vec = vec![4000, 1000, 2000, 7000, 1000, 1000, 2000, 10000, 2000]; - update_layout(&mut cl, &node_id_vec, &node_capacity_vec, &node_zone_vec, 3); - let v = cl.version; - let (mut cl, msg) = cl.apply_staged_changes(Some(v + 1)).unwrap(); - show_msg(&msg); - assert_eq!(cl.check(), Ok(())); - assert!(matches!(check_against_naive(&cl), Ok(true))); - - node_capacity_vec = vec![ - 4000000, 4000000, 2000000, 7000000, 1000000, 9000000, 2000000, 10000, 2000000, - ]; - update_layout(&mut cl, &node_id_vec, &node_capacity_vec, &node_zone_vec, 1); - let v = cl.version; - let (cl, msg) = cl.apply_staged_changes(Some(v + 1)).unwrap(); - show_msg(&msg); - assert_eq!(cl.check(), Ok(())); - assert!(matches!(check_against_naive(&cl), Ok(true))); - } -}