Evaluate different compression tools and their settings by running them on a sample of data.
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README.md

compare_compressors

https://github.com/jdleesmiller/compare_compressors

Build Status

Synopsis

Evaluate different compression tools and their settings by running them on a sample of data.

See this blog post for an example of how to use the tool.

Usage

This utility has many system dependencies, so the easiest way to run it is via Docker:

$ docker pull jdleesmiller/compare_compressors

Generally you will run a compare step, followed by a plot or summarize step.

Compare

This step runs the compressors on the sample files and saves the results to a CSV. Assuming that your sample files are in a folder called data in the current directory, and they are called test1, test2, etc.., the command would look like:

docker run --rm \
  --volume `pwd`/data:/home/app/compare_compressors/data:ro \
  --volume /tmp:/tmp \ # optional
  jdleesmiller/compare_compressors compare data/test* >data/compare.csv

where:

  • The --rm flag tells docker to remove the container when it's finished.

  • The --volume `pwd`/data:/home/app/compare_compressors/data:ro flag mounts ./data on the host inside the container, so the utility can access the sample files. The trick here is that /home/app/compare_compressors is the utility's working directory inside the container, so the relative paths data/test* for the sample files will be the same both inside and outside of the container. The :ro makes it a read only mount; this is optional, but it provides added assurance that the utility won't change your data files.

  • The --volume /tmp:/tmp flag is optional but may improve performance. The utility does its compression and decompression in /tmp inside the container, and all of the writes inside the container go through Docker's union file system. By mounting /tmp on the host, we bypass the union file system. (Ideally, we'd just do this in the Dockerfile, but unfortunately it's 10x slower on Docker for Mac; hopefully that will improve soon.)

Plot

Once you've generated a CSV with results, the tool can read the CSV and generate a gnuplot script to plot the results. Note that you need to have gnuplot installed on the host for this to work.

There are several plotting commands: plot gives you a 2D plot of compression time vs compressed size. There is also a --decompression option to plot decompression time vs compressed size instead.

docker run --rm \
  --volume `pwd`/data:/home/app/compare_compressors/data:ro \
  --volume /tmp:/tmp \
  jdleesmiller/compare_compressors plot data/compare.csv | gnuplot

The plot_costs command takes three cost coefficients: cost per GiB of stored data, cost per hour to run the compression program, and cost per hour to run the decompression program. The program then computes a simple linear cost function. To keep the plot in 2D, the two time costs are added together.

docker run --rm \
  --volume `pwd`/data:/home/app/compare_compressors/data:ro \
  --gibyte-cost 56.05 \
  --compression-hour-cost 32.35 \
  --decompression-hour-cost 177.91 \
  --currency '£' \
  jdleesmiller/compare_compressors plot_costs data/compare.csv | gnuplot

Summarize

Print a list of the compressors and settings in descending order by cost. The cost function is of the same form as for plot_costs.

docker run --rm \
  --volume `pwd`/data:/home/app/compare_compressors/data \
  --gibyte-cost 56.05 \
  --compression-hour-cost 32.35 \
  --decompression-hour-cost 177.91 \
  --currency '£' \
  jdleesmiller/compare_compressors summarize data/compare.csv

Requirements

A linux-like /usr/bin/time utility is required, along with several system packages. See the Dockerfile for a list of the packages that this utility depends on. To make the plot, you will also need gnuplot.

If you are installing natively, without docker, you will need ruby and then to install the gem:

$ gem install compare_compressors

Development

For development, you will probably want (1) override the default entrypoint and (2) mount the application root inside the container. To run the tests, for example:

docker run --rm -it --entrypoint='' \
  --volume=compare_compressors_bundle:/home/app/compare_compressors/.bundle \
  --volume=`pwd`:/home/app/compare_compressors \
  compare_compressors bundle exec rake

The only caveat is that you need to preserve the .bundle folder inside the container by mounting it as a volume; the above command does this using a named volume, compare_compressors_bundle, which will persist between runs and be easier to identify in the docker volume ls output.

Related

License

(The MIT License)

Copyright (c) 2017 John Lees-Miller

Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the 'Software'), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED 'AS IS', WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.