How To Install and uninstall reinstall Elasticsearch 8.15.x on Ubuntu 22.04（vultr）-iaspnetcore.com

不能用root用户启动，报“Caused by: java.lang.RuntimeException: can not run elasticsearch as root”.

https://blog.csdn.net/m0_54219225/article/details/130667081

Elastic.Clients.Elasticsearch version:8.15.3

Elasticsearch version: 8.15.3

.NET runtime version: .NET 8

Operating system version: Ubuntu 22.04

Install Elasticsearch

Install IK

dotnet add package Elastic.Clients.Elasticsearch --version 8.11.0

es7.x和es8.x版本差异比较大

es7和es8的高亮就非常不一样。

Elasticsearch 8.x .NET - Elastic.Clients.Elasticsearch

We have released the next generation of the .NET client for Elasticsearch, which aligns with v8 of Elasticsearch.

We have renamed this library Elastic.Clients.Elasticsearch, and the packages are published on NuGet

https://www.elastic.co/guide/en/elasticsearch/client/net-api/8.15/source-serialization.html

https://www.elastic.co/guide/en/elasticsearch/client/net-api/8.13/connecting.html

Elasticsearch：使用最新的 Elasticsearch Java client 8.0 来创建索引并搜索

我们在学习ES客户端时，一直使用的都是Java High Level Rest Client，在浏览官网时，发现官方给出的警告是：Java REST 客户端已被弃用，取而代之的是 Java API client 客户端，ES 8.x 新版本中，Type 概念被弃用，所以新版 JavaAPI 也相应做出了改变，使用更加简便。ES 官方从 7.15 起开始建议使用新的 JavaAPI

如何使用最新的 Elasticsearch Java client 8.0 来创建索引并进行搜索。最新的 Elasticsearch Java client API 和之前的不同。在es7的一些教程中，经常使用 High Level API 来进行操作。但在官方文档中，已经显示为 deprecated。

Java API Client
官网为啥又推出一个新的客户端接口呢，这是为了统一管理，官网给出的回应是：将来只对这个客户端进行维护改进，这也接口会更加的清晰明了，可读性更高，更易于上手，更简单！代码看着更加简洁了！

无论是ElasticsearchTemplate类还是ElasticsearchRepository接口，都是对ES常用的简单功能进行封装，在实际使用时，复杂的查询语法还是依赖ElasticsearchClient和原生的API封装；

更详细内容参考官网API文档：https://www.elastic.co/guide/en/elasticsearch/client/java-api-client/current/package-structure.html

Elasticsearch 8.15.3 on ubuntu 24.04

Releases · elastic/elasticsearch-net · GitHub https://github.com/elastic/elasticsearch-net

Releases · elastic/elasticsearch-net · GitHub

Migration guide: From NEST v7 to .NET Client v8

https://github.com/infinilabs/analysis-ik

sudo vi /etc/elasticsearch/elasticsearch.yml

Using the .NET Client

Using the .NET Client [8.15]

生成证书指纹

https://blog.csdn.net/willingtolove/article/details/137780194

Semantic Search

you can'nt use attribute mapping .

I'm trying to write a mapping function using V8 client library. But there is not much i can configure. For example in the NEST V7, i can specify analyzer, multifields to a certain field via fluent mapping:
'''
.Text(tt => tt
.Name(zazzleStemmerAnalyzer)
.Analyzer(zazzleStemmerAnalyzer)
.SearchAnalyzer(zazzleStemmerAnalyzer))

But there is no way to add any specification to mapping in V8 client library. The only thing i can do is to map a field to a type:
'''
.Mappings(mappings => mappings.Properties(p => p
.LongNumber(e => e.Id)
.Text(t => t.Title)))

we’re creating an index named ‘flights’ with custom type mappings

var descriptor = new CreateIndexRequestDescriptor(indexName).
    Mappings(m => m
        .Properties(new Properties
        {
            {"FlightNum", new TextProperty() {Analyzer = "standard"}},
            {"FlightCode", new KeywordProperty {IgnoreAbove = 6}}
        }));
 
var response = await _client.Indices.CreateAsync(descriptor, cancellationToken);
return response.IsValidResponse;

https://hamedsalameh.com/full-text-search-with-elasticsearch-and-netcore/

Exception: Invalid NEST response built from a unsuccessful () low level call on PUT: /wwwindex # Audit trail of this API call

ES 8.x新特性

https://blog.csdn.net/star1210644725/article/details/134126478