如何有效地将数据从Elasticsearch索引（具有一个分片）移动到另一索引（具有5个分片）？

Question

I have an elasticsearch index which contains around 5 GB of data on a single node in a single shard. Now I have created another index with same settings as older one, but with number_of_shards as 5 instead of 1.

I am looking for the most efficient approach to copy the data from older index to newer index without any downtime.

Answer 1

I would suggest using Logstash for this. You could use the following configuration. Make sure to replace the source and target hosts, as well as the index and type names to match your local environment.

File: reindex.conf

input {
  elasticsearch {
   hosts => "localhost:9200"       <---- your source host
   index => "my_source_index"
  }
}
filter {
 mutate {
  remove_field => [ "@version", "@timestamp" ]
 }
}
output {
 elasticsearch {
   host => "localhost"       <--- your target host
   port => 9200
   protocol => "http"
   manage_template => false
   index => "my_target_index"
   document_type => "my_type"
   workers => 5
 }
}

And then you can simply launch it with

bin/logstash -f reindex.conf