elasticsearch - 究竟什么是分片？

Question

我正在浏览文档，

An index can potentially store a large amount of data that can exceed the hardware limits of a single node. For example, a single index of a billion documents taking up 1TB of disk space may not fit on the disk of a single node or may be too slow to serve search requests from a single node alone.

To solve this problem, Elasticsearch provides the ability to subdivide your index into multiple pieces called shards. When you create an index, you can simply define the number of shards that you want. Each shard is in itself a fully-functional and independent "index" that can be hosted on any node in the cluster.

究竟是什么构成了弹性搜索分片？它是配置了内存的 lucene 线程吗？是否可以调整单个分片的设置？

Answer 1

除了这个应该有帮助的答案之外，我还可以补充一点，分片实际上包装了一个成熟的 Lucene 搜索引擎。

您不能更改单个分片的设置，而是可以在索引级别更改设置，Elasticsearch 会将它们应用于索引分片。

因此，Elasticsearch 使您能够在位于不同节点的索引的所有分片（即 Lucene 引擎）之间拆分索引上的工作负载。

非常简单地说：Elasticsearch = 分布式 Lucene！