/vmcache

Primary LanguageC++MIT LicenseMIT

vmcache

Code repository for SIGMOD'23 paper "Virtual-Memory Assisted Buffer Management". This is the buffer manager implementation. exmap is in a separate repository.

Environment Variables

  • BLOCK: storage block device (e.g. /dev/nvme0n1 or /dev/md0); default=/tmp/bm
  • VIRTGB: virtual memory allocation in GB (e.g., 1024), should be at least device size; default=16
  • PHYSGB: physical memory allocation in GB = buffer pool size, should be less than available RAM; default=4
  • EXMAP: if non-negative, use exmap interface, requires exmap kernel module; default=0
  • BATCH: batch size for eviction in pages; default=64
  • RUNFOR: benchmark run duration in seconds; default=30
  • RNDREAD: if non-negative, run random read benchmark, otherwise TPC-C; default=0
  • THREADS: number of threads; default=1
  • DATASIZE: number of warehouses for TPC-C, number of tuples for random read benchmark; default=10

Example Command Lines

  • TPC-C, 4 threads, 2 warehouses: BLOCK=/dev/nvme0n1 THREADS=4 DATASIZE=2 ./vmcache
  • random read, 10 threads, 1 million tuples: BLOCK=/dev/md0 THREADS=10 DATASIZE=1e6 ./vmcache

Dependencies and Configuration

We need the libaoi library. On Ubuntu: sudo apt install libaio-dev. You will probably also need to set vm.overcommit_memory = 1 in /etc/sysctl.conf. Otherwise larger values of VIRTGB will not work.

If you want to use EXMAP, you need the exmap kernel module.

Citation

Please cite the paper as follows:

@inproceedings{vmcache,
  author    = {Viktor Leis and Adnan Alhomssi and Tobias Ziegler and Yannick Loeck and Christian Dietrich},
  title     = {Virtual-Memory Assisted Buffer Management},
  booktitle = {SIGMOD},
  year      = {2023},
}

Low-Hanging Fruit (TODO)

  • use C++ wait/notify to handle lock contention instead of spinning
  • implement free space management for storage