Cache algorithms implementation in ABAP
Algos
- Naive: Empty cache when full
- Naive with random eviction
- Classic LRU: Least Recently Used eviction
- 2Q: A low overhead high-performance buffer management replacement algorithm https://citeseerx.ist.psu.edu/document?repid=rep1&type=pdf&doi=e0508499b4cf5794d5aeaf717e7ad9541e9c2bba
- SIEVE: SIEVE is Simpler than LRU: an Efficient Turn-Key Eviction Algorithm for Web Caches NSDI'24 https://yazhuozhang.com/assets/publication/nsdi24-sieve.pdf
- S3-FIFO: "FIFO queues are all you need for cache eviction" ACM SOSP'23 https://doi.org/10.1145/3600006.3613147
Include choosen algorithm in your program. Use CREATE_LCL_* macro to define a local class. Provide StructureName, KeyName and CacheSize. Fill in the code to retrieve data in case it wasn't found in a cache (usually DB selection, but can be anything) Close method and class definition.
Later in a program just call the GET method of the defined local class to retrieve data from the cache.
include ypinc_sieve. " SIEVE cache macro
create_lcl_sieve tdevc devclass 512. " create SIEVE cache of TDEVC structures with DEVCLASS key - size 512 entries
select single * from tdevc into rs_tdevc where devclass = iv_devclass. " data retrival code in case of cache miss
endmethod.
endclass.
... Later in a program ...
data(rs_tdevc) = lcl_sieve_tdevc_by_devclass=>get( ls_tadir-devclass ). " get structure from the cache
Performed on a local ABAP 2022 Trial installation using YP_BENCH_CACHE report
Cache hitratio benchmark
1.000.000 entries from TADIR, caching for TDEVC-DEVCLASS, cache size = 512 entries
Cache type Hits Miss Hit Ratio % Time, sec
-----------------------------------------------------------------------------------------------
Naive cache, empty when full 915.149 84.851 91,5149 0,5338070
Naive cache with random eviction 922.883 77.117 92,2883 0,6916430
LRU cache 925.113 74.887 92,5113 0,6325540
2Q cache (25/75% partition) 926.965 73.035 92,6965 0,8449050
SIEVE cache 926.956 73.044 92,6956 0,5732030
S3FIFO cache 927.151 72.849 92,7151 1,7748800