Clustering benchmarks

K-means is a clustering algorithm - we compare the reference implementation provided by scikit-learn with the Rust implementation provided by linfa.

In order to perform a fair comparison, we also include performance measured calling linfa from Python, using its same name Python wrapper linfa, available on PyPi. We'll refer to it as linfa (Python wrapper) for clarity.

In particular, we compare:

• training times;
• inference time, as measured when the model is exposed as a gRPC microservice.

This repository contains all the source code required to reproduce the benchmarks as well as instructions to do so.

Results

Training

linfa (Python wrapper) is ~1.3x faster than scikit-learn in training a K-Means model on a dataset of 1 million points:

Overall, their speed is comparable - linfa is probably slightly faster due to the parallel assignment step.

Inference

linfa on a Rust web server provides ~25x better performance (requests per second, latency) compared to scikit-learn and ~7x compared to linfa (Python wrapper) on a Python web server. It also provides the lowest error rate under heavy load.

For inference, linfa (Python wrapper) provides a 3.5x increase in throughput (number of requests per second) compared to scikit-learn using the same underlying web server (Python's grpcio).

linfa on a Rust web server (tonic) handles 25x more requests per second than scikit-learn and 7x more than linfa (Python wrapper) on a Python web server.

The same holds for latency (how long it takes to provide a response), where linfa (Python wrapper) is consistently ~3.5x faster than scikit-learn across all percentiles.

linfa on a Rust web server is consistently 26x faster than scikit-learn and 7x faster than than linfa (Python wrapper) on a Python web server.

The Python web-server remains more stable under heavy load when serving linfa (Python wrapper) compared to scikit-learn in terms of error rate (% of failed requests over total).

linfa on a Rust web server has the lowest error rate under heavy load.

Training benchmark

We compare how long it takes to train a K-means model for:

• scikit-learn, with init="random", algorithm="full" (Lloyds' algorithm);
• linfa-k-means (Lloyds' algorithm, Python wrapper around the linfa-clustering Rust implementation).

We use the same hyperparameters for all models:

• maximum number of iterations, 100;
• tolerance, 1e-4;
• number of clusters, 3.

The comparison is run from Python using pytest's benchmarking functionality on a synthetic dataset of 1 million points.

Running the benchmark

cd python-grpc
# Install the required packages in a virtual environment
poetry install
poetry run pytest

Inference benchmark

We compare the inference performance of the K-Means model exposed as a gRPC microservice. The following setups are compared:

• scikit-learn exposed with Python's grpcio;
• linfa-k-means exposed with Python's grpcio;
• linfa-clustering exposed with Rust's tonic.

The comparison is run using ghz.

Test data

The data used for the inference benchmark can be found in the data folder.

The utils under rust-grpc/src/bin can be used to generate additional/different test data. Check rust-grpc/README.md for more details.

Launching the gRPC microservices

Launch Python's microservice on port 5001, serving scikit-learn's model:

cd python-grpc
# Install the required packages in a virtual environment
poetry install
poetry run python src/main.py

Launch Python's microservice on port 5001, serving linfa's model (Python wrapper over Rust):

cd python-grpc
# Install the required packages in a virtual environment
poetry install
RUST=true poetry run python src/main.py

Launch Rust's microservice on port 5001, serving linfa's model (Rust):

cd rust-grpc
cargo run --release -- --port 5001 --model=../data/rust_k_means_model.json

Running the benchmark

After you have launched the microservice you want to benchmark, you can measure its performance with:

ghz \
    --proto=protos/centroids.proto \
    --call=ml.ClusteringService.Predict \
    --insecure \
    --data-file=data/observations.json \
    --duration 30s \
    --concurrency $concurrency \
    --format json \
    localhost:5001 \

All benchmarks run for 30s, testing different levels of client-side concurrency (64, 128, 256, 512, 1024 concurrent requests) for each server.

If you want to skip a lot of manual error-prone command typing, you can use the run_benchmark.sh bash script. Result summaries can be found under grpc-benchmark-outputs.

Machine specs

All the benchmarks have been run on the same machine, with following specifics:

• CPU: AMD Ryzen 7 1700 Eight-Core Processor
• RAM: 4x8GB DDR4