I. Overview
Introduces the core concepts among es, which will run through the core concepts in our entire study period.
II. Index
Among the current version es7, because the type is no longer recommended for use, so for us to understand the index can be considered similar to a relational database table data.
Comparative relational database, the concept of the table and the index data is basically the same data table have a table structure, also have the same index structure, known Mapping.
III. Documentation
Among the relational database, the unit of data is stored in our records. Among es, the document units we store data.
Json basically the same structure and the structure of the document.
IV. Node
We normally es instance a run is called a node, of course, a physical machine may have several nodes.
V. Cluster
Multiple nodes can be clustered to provide overall coordination of services between them by external services.
Six .shard - fragment
Among the ES, an index data may be stored on a plurality of slice so that when the content index is large enough that the storage capacity is divided into a plurality of slices, and a plurality of slices can exist on multiple nodes.
Es so it has a higher storage capacity.
VII. Copies
Among es, designed for highly available, a copy of the proposed concept. Each corresponds to a copy of fragmentation, fragmentation occurs when the problem, we can replace the fragmented copy of the cluster es can provide normal service.