Elasticsearch вопросы и ответы для интервью

Вопрос 46. Explain the role of the 'Cluster State' in Elasticsearch.

The Cluster State holds information about the entire cluster, including metadata about indices, nodes, and shards.

Вопрос 47. What is the purpose of the 'Aggregations' framework in Elasticsearch?

Aggregations in Elasticsearch provide the ability to perform data analysis on the results of a query. They enable you to extract and process aggregated information from the data.

Example:

GET /my_index/_search
{
  "aggs": {
    "average_price": {
      "avg": {
        "field": "price"
      }
    }
  }
}

Вопрос 48. What is the purpose of the 'Recovery' process in Elasticsearch?

Recovery is the process of restoring a shard to a consistent state after a node failure or restart.

Вопрос 49. How does the 'Geo-Point' type work in Elasticsearch?

The 'Geo-Point' type in Elasticsearch is used to index and search for geographical coordinates, such as latitude and longitude. It enables spatial queries for location-based data.

Example:

PUT /my_index
{
  "mappings": {
    "properties": {
      "location": {
        "type": "geo_point"
      }
    }
  }
}

Вопрос 50. How does Elasticsearch handle conflicts during distributed writes?

Elasticsearch uses versioning to handle conflicts during distributed writes, ensuring data consistency.