Definitions

Domain: The primary container for all OpenSearch resources. It represents the entire environment where your data is stored and indexed.

Node: A single instance of OpenSearch running within your domain. Nodes work together to form a cluster and distribute the workloads and data among them.

Leader nodes: Nodes that perform cluster management tasks but do not hold data or respond to data requests.

Dedicated leader nodes: Nodes that serve exclusively as specialized nodes that are configured to perform the role of a leader.

Data nodes: Nodes that are responsible for storing and managing data. Data nodes handle indexing and searching operations and store the actual index and document data.

UltraWarm and cold nodes: UltraWarm nodes provide a cost-effective way to store large amounts of read-only data on Amazon OpenSearch Service. Rather than attached storage, UltraWarm nodes use Amazon S3 and a sophisticated caching solution to improve performance.

Multi-AZ with Standby: A deployment option for Amazon OpenSearch Service domains providing 99.99% availability and consistent performance by spanning three Availability Zones, each with a complete data copy.

Index: A data structure used to store, organize, and search documents, similar to a database table.

Shard: A smaller, more manageable segment of an index. Each shard acts as a self-contained index, and in Amazon OpenSearch Service, shards are distributed across data nodes for load balancing, redundancy, and fault tolerance.

Replica: A duplication of a shard, offering failover and load balancing capabilities. Amazon OpenSearch Service automatically distributes replica shards across various nodes within the domain.

Document: A single unit of searchable data, like a row in a database table. Each document possesses a unique identification (ID) and encompasses a set of fields.

Field: A named, typed value within a document, resembling a column in a database table. Fields may have various data types, including string, number, date, or Boolean.

Mapping: Defines the structure of documents in an index, including field names, data types, and other metadata. It acts as a schema for the documents and helps Amazon OpenSearch Service understand the data and optimize search performance.

Query: A request to search, filter, or aggregate data from an OpenSearch index. Amazon OpenSearch Service accommodates various query types, including term, match, range, and Boolean queries.

Aggregation: A process of grouping and summarizing data based on specified criteria. OpenSearch supports various aggregation types, such as bucket aggregations, metric aggregations, and pipeline aggregations.

Snapshot: Refers to a point-in-time copy of the data in one or more indices. It is essentially a backup mechanism that captures the state of your data at a specific moment.