elasticsearch 2.2+ index.codec: best_compression启用压缩
官方说法，来自https://www.elastic.co/guide/en/elasticsearch/reference/2.2/index-modules.html#_static_index_settings： index.codecThedefaultvalue compresses stored data with LZ4 compression, but this can be set tobest_compressionwhich usesDEFLATEfor a higher compression ratio, at the expense of slower stored fields performance. 注意：2.1以下都是实验特性！2.2+才稳定！ Now you can also enable better compression on the cold nodes by settingindex.codec: best_compressionin theirconfig/elasticsearch.ymlfile in order to be able to archive more data with the same amount of disk space. 摘自：https://www.elastic.co/blog/store-compression-in-lucene-and-elasticsearch 下面的数据摘自：https://www.elastic.co/blog/elasticsearch-storage-the-true-story-2.0 The test methodology hasn’t changed so you can check out theold blog postor theREADME in the Github repofor the details. Test String fields _all index size /w LZ4 index size /w DEFLATE expansion ratio /w LZ4 expansion ratio /w DEFLATE Impact of DEFLATE Structured data file. Original file size:67644119 1 analyzed and not_analyzed enabled 63047579 53131592 0.932 0.785 -0.157 2 analyzed and not_analyzed disabled 48271433 38327106 0.713 0.566 -0.206 3 not_analyzed disabled 38920800 29014796 0.575 0.428 -0.254 3b not_analyzed, except for 'message' field which is retained and analyzed disabled 65382872 49532858 0.966 0.732 -0.242 4 not_analyzed, except for 'agent' field which is analyzed disabled 43083702 32063602 0.636 0.474 -0.255 Semi-structured data file.Original file size:75037027 1 analyzed and not_analyzed enabled 100478376 82132782 1.339 1.094 -0.182 2 analyzed and not_analyzed disabled 75238480 56911638 1.002 0.758 -0.243 3 not_analyzed disabled 71866672 53553561 0.957 0.713 -0.254 3b not_analyzed, except for 'message' field which is retained and analyzed disabled 104638750 83824398 1.394 1.117 -0.198 4 not_analyzed, except for 'agent' field which isanalyzed disabled 72925624 54603882 0.971 0.727 -0.251 With the standard LZ4-based compression, the indexed data size to raw data size ratio ranged from 0.575 to 1.394. After enabling DEFLATE-based compression using the best_compression index.codec option, the indexed data size to raw data size ratio range came down to 0.429 to 1.117. Enabling the best_compression option resulted in a 15.7% to 25.6% reduction in indexed data size depending on the test parameters. As you can see, the ratio of index size to raw data size can vary greatly based on your mapping configuration, what fields you decide to create/retain, and the characteristics of the data set itself. We encourage you to run similar tests yourself to determine what the data compression/expansion factor is for your data set and application requirements. Conclusion There weremany amazing featuresadded to Elasticsearch 2.0 worth considering. As we’ve discussed, two of these new features in particular can reduce the hardware footprint required for an Elasticsearch cluster by 15-25% or more: 1) the addition of a best_compression option and 2) enabling doc_values by default. This allows us to get to compression ratios between 0.429 and 1.117. 本文转自张昺华-sky博客园博客，原文链接：http://www.cnblogs.com/bonelee/p/6269582.html，如需转载请自行联系原作者
