diff options
| -rw-r--r-- | src/rpc/graph_algo.rs | 8 |
1 files changed, 6 insertions, 2 deletions
diff --git a/src/rpc/graph_algo.rs b/src/rpc/graph_algo.rs index 0e88efc4..d8c6c9b9 100644 --- a/src/rpc/graph_algo.rs +++ b/src/rpc/graph_algo.rs @@ -1,7 +1,7 @@ //! This module deals with graph algorithms. //! It is used in layout.rs to build the partition to node assignment. -use rand::prelude::SliceRandom; +use rand::prelude::{SeedableRng, SliceRandom}; use std::cmp::{max, min}; use std::collections::HashMap; use std::collections::VecDeque; @@ -143,7 +143,11 @@ impl Graph<FlowEdge> { /// This function shuffles the order of the edge lists. It keeps the ids of the /// reversed edges consistent. fn shuffle_edges(&mut self) { - let mut rng = rand::thread_rng(); + // We use deterministic randomness so that the layout calculation algorihtm + // will output the same thing every time it is run. This way, the results + // pre-calculated in `garage layout show` will match exactly those used + // in practice with `garage layout apply` + let mut rng = rand::rngs::StdRng::from_seed([0x12u8; 32]); for i in 0..self.graph.len() { self.graph[i].shuffle(&mut rng); // We need to update the ids of the reverse edges. |