Compressor Microbenchmark: Basho LevelDB

Symas Corp., February 2015

Test Results

Synchronous Random Write

The synchronous tests only use 1000 records so there's not much to see here. 1000 records with 100 byte values and 16 byte keys should only occupy 110KB but the size is consistently over 140KB here, showing a fixed amount of incompressible overhead in the DB engine.

Random Write

The asynchronous tests use 1000000 records and, while showing no significant difference in throughput, show widely varying results for the DB sizes. Basho goes to great lengths to maintain constant write rates, which explains the relative uniformity of the throughput for each compressor. What's unexpected is that some of the compressors yield DBs much larger than the uncompressed case.

Random Batched Write

Synchronous Sequential Write

The synchronous tests only use 1000 records so there's not much to see here.

Sequential Write

Sequential Batched Write

Random Overwrite

Read-Only Throughput

In the read-only tests we also find that using some of the compressors yields faster throughput than the uncompressed case.


These charts show the final stats at the end of the run, after all compactions completed. The RSS shows the maximum size of the process for a given run. The times are the total User and System CPU time, and the total Wall Clock time to run all of the test operations for a given compressor.

The huge amount of system CPU time in the lzma run indicates a lot of malloc overhead in that library. At a cost of 50% more RAM usage, the test with zlib yields both the smallest DB and the quickest runtime.


The files used to perform these tests are all available for download.

The command script: Raw output: out.basho.txt. OpenOffice spreadsheet Basho.ods.