Compressed Database Cache Backend

This module provides a cache backend which leverages gzip compression for the
stored data.

Upon cache set the cache data will be gzipped, if the gzipped data is smaller
than the original data the compressed data will be stored in the cache bin.

This Database Backend adds two additional states to serialized column of Drupal
cores DatabaseBackend.

- SERIALIZED_COMPRESSED (2): a serialized object, compressed.
- STRING_SERIALIZED_COMPRESSED (3): a compressed string.

Benchmark

100k+ nodes, same time needed for generation as with the default database backend. Storage comparison:

bin	default database backend (total size in MB)	compressed cache database backend (total size in MB)	reduction in %
cache_data	4385,48	532,48	87,85811359
cache_dynamic_page_cache	12419,56	4486,42	63,87617597
cache_page	20641,09	5701,08	72,37994699
cache_render	7026,89	3110,8	55,73005981

Please add your findings to Benchmarks, comparison

Requirements

php functions: gzcompress, gzuncompress come with zlib extension.

Installation

download and install the module as ususal.

Swap the existing database backend with our compressed one in settings.php:

    // Default cache bin
    $settings['cache']['default'] = 'cache.backend.database_compressed_cache';
    // Specific cache bins
    $settings['cache']['bins']['data'] = 'cache.backend.database_compressed_cache';
    $settings['cache']['bins']['dynamic_page_cache'] = 'cache.backend.database_compressed_cache';
    $settings['cache']['bins']['render'] = 'cache.backend.database_compressed_cache';
    $settings['cache']['bins']['page'] = 'cache.backend.database_compressed_cache';

Advanced settings

/**
     * Compression level
     * default = 6
     * @see http://php.net/gzcompress
     */
    $settings['compressed_cache']['cache_compression_ratio'] = 1;

    /**
     * Minimum string length to add compression.
     * Seems to be completely based on gut feeling. can not find any sources googling this topic.
     */
    $settings['compressed_cache']['cache_compression_size_threshold'] = 100;
    
    /**
     * Whether garbage collection is enabled or not. Defaults to TRUE.
     */
    $settings['compressed_cache']['garbage_collection_enabled'] = TRUE;

Related issues

Project information

Minimally maintained
Maintainers monitor issues, but fast responses are not guaranteed.
Module categories: Performance
365 sites report using this module
Created by Andre-B on 19 April 2018, updated 13 August 2018
Stable releases for this project are covered by the security advisory policy.
Look for the shield icon below.