On my elasticsearch server: total documents: 3 million, total size: 3.6G Then, I delete about 2.8 millions documents: total documents: about 0.13 million, total size: 3.6G
I have deleted the documents, how should I free the size of the documents?
62
votes
4 Answers
98
votes
Deleting documents only flags these as deleted, so they would not be searched. To reclaim disk space, you have to optimize the index:
curl -XPOST 'http://localhost:9200/_optimize?only_expunge_deletes=true'
documentation: http://www.elasticsearch.org/guide/en/elasticsearch/reference/current/indices-optimize.html
The documentation has moved to: https://www.elastic.co/guide/en/elasticsearch/reference/current/indices-forcemerge.html
Update
Starting with Elasticsearch 2.1.x, optimize is deprecated in favor of forcemerge.
The API is the same, only the endpoint did change.
curl -XPOST 'http://localhost:9200/_forcemerge?only_expunge_deletes=true'
32
votes
In the current elasticsearch version(7.5),
To optimize all indices:
POST /_forcemerge?only_expunge_deletes=trueTo optimize single index
POST /twitter/_forcemerge?only_expunge_deletes=true, where twitter is the indexTo optimize several indices
POST /twitter,facebook/_forcemerge?only_expunge_deletes=true, where twitter and facebook are the indices
6
votes
knutwalker's answer is correct. However if you are using AWS ElasticSearch and want to free storage space, this will not quite work.
On AWS the index to forgemerge must be specified in the URL. It can include wildcards as is common with index rotation.
curl -XPOST 'https://something.es.amazonaws.com/index-*/_forcemerge?only_expunge_deletes=true'
AWS publishes a list of ElasticSearch API differences.
