Skip to content

perf!: remove shuffle buffer #5912

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Merged
westonpace merged 3 commits into from
Feb 10, 2026
Merged

perf!: remove shuffle buffer #5912

Changes from all commits
Commits
Show all changes
3 commits
Select commit Hold shift + click to select a range
74efab5
perf!: remove shuffle buffer
wkalt Feb 8, 2026
33b50fa
lint
wkalt Feb 8, 2026
8f12f82
make writes concurrent
wkalt Feb 9, 2026
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
44 changes: 6 additions & 38 deletions rust/lance-index/src/vector/v3/shuffler.rs
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -9,8 +9,7 @@ use std::sync::Arc;
use arrow::{array::AsArray, compute::sort_to_indices};
use arrow_array::{RecordBatch, UInt32Array};
use arrow_schema::Schema;
use future::try_join_all;
use futures::prelude::*;
use futures::{future::try_join_all, prelude::*};
use lance_arrow::{RecordBatchExt, SchemaExt};
use lance_core::{
cache::LanceCache,
Expand Down Expand Up @@ -69,7 +68,6 @@ pub struct IvfShuffler {
num_partitions: usize,

// options
buffer_size: usize,
precomputed_shuffle_buffers: Option<Vec<String>>,
}

Expand All @@ -79,16 +77,10 @@ impl IvfShuffler {
object_store: Arc::new(ObjectStore::local()),
output_dir,
num_partitions,
buffer_size: 4096,
precomputed_shuffle_buffers: None,
}
}

pub fn with_buffer_size(mut self, buffer_size: usize) -> Self {
self.buffer_size = buffer_size;
self
}

pub fn with_precomputed_shuffle_buffers(
mut self,
precomputed_shuffle_buffers: Option<Vec<String>>,
Expand Down Expand Up @@ -163,44 +155,20 @@ impl Shuffler for IvfShuffler {
})
.buffered(get_num_compute_intensive_cpus());

// part_id: | 0 | 1 | 3 |
// partition_buffers: |[batch,batch,..]|[batch,batch,..]|[batch,batch,..]|
let mut partition_buffers = vec![Vec::new(); num_partitions];

let mut counter = 0;
let mut total_loss = 0.0;
while let Some(shuffled) = parallel_sort_stream.next().await {
let (shuffled, loss) = shuffled?;
total_loss += loss;

for (part_id, batches) in shuffled.into_iter().enumerate() {
let part_batches = &mut partition_buffers[part_id];
part_batches.extend(batches);
}

counter += 1;

// do flush
if counter % self.buffer_size == 0 {
let mut futs = vec![];
for (part_id, writer) in writers.iter_mut().enumerate() {
let batches = &partition_buffers[part_id];
let mut futs = Vec::new();
for (part_id, (writer, batches)) in writers.iter_mut().zip(shuffled.iter()).enumerate()
{
if !batches.is_empty() {
partition_sizes[part_id] += batches.iter().map(|b| b.num_rows()).sum::<usize>();
futs.push(writer.write_batches(batches.iter()));
}
try_join_all(futs).await?;

partition_buffers.iter_mut().for_each(|b| b.clear());
}
}

// final flush
for (part_id, batches) in partition_buffers.into_iter().enumerate() {
let writer = &mut writers[part_id];
partition_sizes[part_id] += batches.iter().map(|b| b.num_rows()).sum::<usize>();
for batch in batches.iter() {
writer.write_batch(batch).await?;
}
try_join_all(futs).await?;
}

// finish all writers
Expand Down
Loading