Elastic Search : Basic concepts and how to do setup

About Elastic search:

-Near real time search platform

-Each index can be horizontally splitted into multiple shards.

Each shards can have own replicas.

Replication helps in

-High availability

-Scale out search /throughput, as  search can be executed on replicas in parallel

Steps to setup elastic search:

1. Adding Schema:

PUT / INDEX_NAME

"mappings": {

         "Index_name": {

}

,

      "settings": {

         "index": {

            "number_of_replicas": "1",

            "number_of_shards": "1"

         }

      }

   }

2. Add Domain Schema (equivalent to table)

PUT /index_name

{

      "mappings": {

         "index_type": {

            "properties": {

               "firstName": {

                  "type": "string"

               },

 "secondName": {

                  "type": "string"

               },

 "location": {

                  "type": "string"

                  "index": "not_analyzed"

               }

}

}

3.Add data

PUT index_name/index_type/documentId1

{

                     "firstName" :" hello",

                     "secondName": "world"

                           "location"": "Malesia-Singapore"

}

GET INDEX_NAME/ INDEX_TYPE/Id

PUT INDEX_NAME / INDEX_TYPE /1

{

   "body": "here"

}

DELETE index_name/index_type/<id>

   Query search  :           

  GET INDEX_NAME 

  {

  "query" : {

    <json_query>

  }

}

All search:

GET INDEX_NAME/INDEX_TYPE/_search{

GET _search

{

  "query": {

    "match_all": {}

  }

}

Executing term query

get index_name/index_type/_search

{

  "query": {

    "term": {

      "location": "Malesia-Singapore"

    }

  }

}