LightSaber

LightSaber is a stream processing engine that balances parallelism and incremental processing when executing window aggregation queries on multi-core CPUs. LightSaber operates on in-order streams of data and achieves up to an order of magnitude higher throughput compared to existing systems.

Getting started

The prepare-software.sh script will guide you through the installation and compilation process of our system locally. The script is tested on Ubuntu 18.04.5 LTS.

$ git clone https://github.com/lsds/LightSaber.git
$ cd LightSaber
$ ./scripts/prepare-software.sh
$ ./scripts/build.sh

Otherwise use the Dockerfile:

$ git clone https://github.com/lsds/LightSaber.git
$ cd LightSaber
$ docker build --tag="lightsaber" .
$ docker run -ti lightsaber

Run unit tests

$ ./build/test/unit_tests/unit_tests_run

Running a microbenchmark (e.g., Projection)

$ ./build/test/benchmarks/microbenchmarks/TestProjection

Running an application benchmark with sample data

$ ./build/test/benchmarks/applications/cluster_monitoring

How to cite LightSaber

• [SIGMOD] Georgios Theodorakis, Alexandros Koliousis, Peter R. Pietzuch, and Holger Pirk. LightSaber: Efficient Window Aggregation on Multi-core Processors, SIGMOD, 2020

@inproceedings{Theodorakis2020,
 author = {Georgios Theodorakis and Alexandros Koliousis and Peter R. Pietzuch and Holger Pirk},
 title = {{LightSaber: Efficient Window Aggregation on Multi-core Processors}},
 booktitle = {Proceedings of the 2020 ACM SIGMOD International Conference on Management of Data},
 series = {SIGMOD '20},
 year = {2020}, 
 publisher = {ACM},
 address = {Portland, OR, USA},
}

Other related publications

• [EDBT] Georgios Theodorakis, Peter R. Pietzuch, and Holger Pirk. SlideSide: A fast Incremental Stream Processing Algorithm for Multiple Queries, EDBT, 2020
• [ADMS] Georgios Theodorakis, Alexandros Koliousis, Peter R. Pietzuch, and Holger Pirk. Hammer Slide: Work- and CPU-efficient Streaming Window Aggregation, ADMS, 2018 [code]
• [SIGMOD] Alexandros Koliousis, Matthias Weidlich, Raul Castro Fernandez, Alexander Wolf, Paolo Costa, and Peter Pietzuch. Saber: Window-Based Hybrid Stream Processing for Heterogeneous Architectures, SIGMOD, 2016

The LightSaber engine

LightSaber configuration

Variables in SystemConf.h configure the LightSaber runtime. Each of them also corresponds to a command-line argument available to all LightSaber applications:

--threads N

Sets the number of CPU worker threads (WORKER_THREADS variable). The default value is 1. CPU worker threads are pinned to physical cores. The threads are pinned to core ids based on the underlying hardware (e.g., if there are multiple sockets with n cores each, the first n threads are pinned in the first socket and so on).

--slots N

Sets the number of intermediate query result slots (SLOTS variable). The default value is 256.

--partial-windows N

Sets the maximum number of window fragments in a query task (PARTIAL_WINDOWS variable). The default value is 1024.

--circular-size N

Sets the circular buffer size in bytes (CIRCULAR_BUFFER_SIZE variable). The default value is 4194304, i.e. 4 MB.

--unbounded-size N

Sets the intermediate result buffer size in bytes (UNBOUNDED_BUFFER_SIZE variable). The default value is 524288, i.e. 512 KB.

--hashtable-size N

Hash table size (in number of buckets): hash tables hold partial window aggregate results (HASH_TABLE_SIZE variable with the default value 512).

--performance-monitor-interval N

Sets the performance monitor interval, in msec (PERFORMANCE_MONITOR_INTERVAL variable). The default value is 1000, i.e. 1 sec. Controls how often LightSaber prints on standard output performance statistics such as throughput and latency.

--latency true|false

Determines whether LightSaber should measure task latency or not (LATENCY_ON variable). The default value is false.

To enable NUMA-aware scheduling

Set the HAVE_NUMA flag in the respective CMakeLists.txt (e.g., in test/benchmarks/applications/CMakeLists.txt) and recompile the code.