Elasticsearch最佳实践

前置知识

在学习本文之前，请确保您已经：

• 掌握Elasticsearch的基本使用
• 了解Elasticsearch的高级特性
• 有实际的项目开发经验

索引设计最佳实践

1. 合理设计Mapping

PUT my_index
{
  "mappings": {
    "properties": {
      "id": {
        "type": "keyword"
      },
      "title": {
        "type": "text",
        "analyzer": "ik_max_word",
        "fields": {
          "keyword": {
            "type": "keyword",
            "ignore_above": 256
          }
        }
      },
      "description": {
        "type": "text",
        "analyzer": "ik_max_word"
      },
      "price": {
        "type": "scaled_float",
        "scaling_factor": 100
      },
      "createTime": {
        "type": "date",
        "format": "yyyy-MM-dd HH:mm:ss||yyyy-MM-dd||epoch_millis"
      }
    }
  }
}

2. 索引模板

@Service
@RequiredArgsConstructor
public class IndexTemplateService {
    private final RestHighLevelClient client;
    
    public void createTemplate() throws IOException {
        PutIndexTemplateRequest request = new PutIndexTemplateRequest("my_template");
        
        request.patterns(Arrays.asList("product-*"));
        request.order(0);
        
        Map<String, Object> mappings = new HashMap<>();
        // ... 设置mappings
        
        Map<String, Object> settings = new HashMap<>();
        // ... 设置settings
        
        request.mapping(mappings);
        request.settings(settings);
        
        client.indices().putTemplate(request, RequestOptions.DEFAULT);
    }
}

性能优化最佳实践

1. 批量操作

public class BulkOperationService {
    private final ElasticsearchOperations elasticsearchOperations;
    private final int BATCH_SIZE = 1000;
    
    public void bulkIndex(List<Product> products) {
        List<IndexQuery> queries = new ArrayList<>();
        
        for (Product product : products) {
            IndexQuery indexQuery = new IndexQueryBuilder()
                .withId(product.getId())
                .withObject(product)
                .build();
            queries.add(indexQuery);
            
            // 达到批量大小时执行
            if (queries.size() == BATCH_SIZE) {
                elasticsearchOperations.bulkIndex(queries, Product.class);
                queries.clear();
            }
        }
        
        // 处理剩余的文档
        if (!queries.isEmpty()) {
            elasticsearchOperations.bulkIndex(queries, Product.class);
        }
    }
}

2. 查询优化

public SearchHits<Product> optimizedSearch(
    String keyword, String category, Double minPrice, Double maxPrice) {
    
    BoolQueryBuilder boolQuery = QueryBuilders.boolQuery();
    
    // 关键词搜索
    if (StringUtils.hasText(keyword)) {
        boolQuery.must(QueryBuilders.multiMatchQuery(keyword)
            .field("title", 3.0f)
            .field("description")
            .type(MultiMatchQueryBuilder.Type.BEST_FIELDS));
    }
    
    // 过滤条件
    if (StringUtils.hasText(category)) {
        boolQuery.filter(QueryBuilders.termQuery("category", category));
    }
    
    if (minPrice != null || maxPrice != null) {
        RangeQueryBuilder rangeQuery = QueryBuilders.rangeQuery("price");
        if (minPrice != null) rangeQuery.gte(minPrice);
        if (maxPrice != null) rangeQuery.lte(maxPrice);
        boolQuery.filter(rangeQuery);
    }
    
    // 使用PageRequest替代Scroll
    NativeSearchQuery searchQuery = new NativeSearchQueryBuilder()
        .withQuery(boolQuery)
        .withPageable(PageRequest.of(0, 20))
        .withSort(SortBuilders.fieldSort("_score").order(SortOrder.DESC))
        .withSort(SortBuilders.fieldSort("createTime").order(SortOrder.DESC))
        .build();
    
    return elasticsearchOperations.search(searchQuery, Product.class);
}

监控与运维最佳实践

1. 健康检查

@Service
@RequiredArgsConstructor
public class HealthCheckService {
    private final RestHighLevelClient client;
    
    public boolean isClusterHealthy() {
        try {
            ClusterHealthResponse response = client.cluster().health(
                new ClusterHealthRequest(),
                RequestOptions.DEFAULT
            );
            
            return response.getStatus() != ClusterHealthStatus.RED;
        } catch (IOException e) {
            return false;
        }
    }
    
    public Map<String, Object> getClusterStats() {
        try {
            ClusterStatsResponse response = client.cluster().stats(
                new ClusterStatsRequest(),
                RequestOptions.DEFAULT
            );
            
            Map<String, Object> stats = new HashMap<>();
            stats.put("nodes", response.getNodesStats());
            stats.put("indices", response.getIndicesStats());
            return stats;
        } catch (IOException e) {
            return Collections.emptyMap();
        }
    }
}

2. 数据备份

@Service
@RequiredArgsConstructor
public class BackupService {
    private final RestHighLevelClient client;
    
    public CreateSnapshotResponse createSnapshot(
        String repositoryName,
        String snapshotName
    ) throws IOException {
        CreateSnapshotRequest request = new CreateSnapshotRequest()
            .repository(repositoryName)
            .snapshot(snapshotName)
            .waitForCompletion(true);
        
        return client.snapshot().create(request, RequestOptions.DEFAULT);
    }
    
    public RestoreSnapshotResponse restoreSnapshot(
        String repositoryName,
        String snapshotName
    ) throws IOException {
        RestoreSnapshotRequest request = new RestoreSnapshotRequest()
            .repository(repositoryName)
            .snapshot(snapshotName)
            .waitForCompletion(true);
        
        return client.snapshot().restore(request, RequestOptions.DEFAULT);
    }
}

安全配置最佳实践

1. 身份认证

# elasticsearch.yml
xpack.security.enabled: true
xpack.security.transport.ssl.enabled: true

@Configuration
public class ElasticsearchConfig {
    
    @Bean
    public RestHighLevelClient elasticsearchClient() {
        final CredentialsProvider credentialsProvider =
            new BasicCredentialsProvider();
        
        credentialsProvider.setCredentials(AuthScope.ANY,
            new UsernamePasswordCredentials("elastic", "password"));
        
        RestClientBuilder builder = RestClient.builder(
            new HttpHost("localhost", 9200, "https"))
            .setHttpClientConfigCallback(httpClientBuilder -> httpClientBuilder
                .setDefaultCredentialsProvider(credentialsProvider)
                .setSSLContext(createSSLContext()));
        
        return new RestHighLevelClient(builder);
    }
    
    private SSLContext createSSLContext() {
        // ... SSL配置代码
        return null;
    }
}

2. 角色权限

# 创建角色
POST /_security/role/read_only
{
  "cluster": ["monitor"],
  "indices": [
    {
      "names": ["product-*"],
      "privileges": ["read", "view_index_metadata"]
    }
  ]
}

总结

本文介绍了Elasticsearch的以下最佳实践：

1. ✅ 索引设计优化
2. ✅ 性能调优方案
3. ✅ 监控与运维
4. ✅ 安全配置

建议

• 根据实际业务场景选择合适的实践方案
• 定期进行性能测试和优化
• 建立完善的监控和告警机制

希望这篇文章对您有所帮助！如果您有任何问题，欢迎在评论区讨论。