Attic : Install and Configure Elasticsearch on RHEL 6.6

Download the Elasticsearch RPM package (version 2.1.2) from the Elasticsearch website and install it:

wget https://download.elasticsearch.org/elasticsearch/release/org/elasticsearch/distribution/rpm/elasticsearch/2.1.2/elasticsearch-2.1.2.rpm

rpm -ivh elasticsearch-2.1.2.rpm

Install the Elasticsearch search server, preferably using Homebrew:

brew install elasticsearch21

Modify the elasticsearch.yml file in /etc/elasticsearch to start Elasticsearch on the elasticsearch_cedar cluster:

cluster.name: elasticsearch_cedar

Add or change the below line to enable script execution:

script.engine.groovy.inline.search: on

Start Elasticsearch:

elasticsearch

Configure Elasticsearch

Cedar Search (cedar-search index)

Configuration to work with the cedar-search index:

• Cluster: elasticsearch_cedar
• Index: cedar-search
• Type: resources

Some useful queries:

Show all resources: GET cedar-search/resources/_search

Show mappings: GET cedar-search/_mapping/resources

Value Recommender (cedar index)

More info about the Value Recommender Server here.

We will use curl to define a custom analyzer and apply it using a dynamic template. The default tokenizer used by Elasticsearch splits each string into individual words, but that default behavior is not appropriate for our value recommendation functionality. We need that the system recommends full values (e.g. "Longitudinal Study") instead of splitting them into individual words (e.g. "Longitudinal", "Study"). We use the keyword tokenizer to output exactly the same string as it received, without any tokenization. The lowercase filter normalizes the text to lower case. We also use a dynamic template to apply our custom analyzer to all fields.

$ curl -XPUT 'http://localhost:9200/cedar' -d '
{
  "settings":{
     "index":{
        "analysis":{
           "analyzer":{
              "analyzer_keyword":{
                 "tokenizer":"keyword",
                 "filter":"lowercase"
              }
           }
        }
     }
  },
  "mappings": {
    "template_instances": {
      "dynamic_templates": [
        {
          "my_template": {
            "match": "*",
            "match_mapping_type": "string",
            "mapping": {
              "type": "string",
              "analyzer":"analyzer_keyword"
            }
          }
        }
      ]
    }
  }
}

Configuration to work with the cedar index:

• Cluster: elasticsearch_cedar
• Index: cedar
• Type: template_instances

Some useful queries:

Cluster health: GET _cluster/health

List all indices: GET _cat/indices/?v

Get all types and instances: GET _mapping

Get all documents in a given index, of a particular type: GET {cluster_name}/{index_name}/_search Example: GET cedar/template_instances/_search

Delete an index: DELETE {index_name} Example: DELETE cedar