Elasticsearch性能优化 #

优化维度
├── 硬件优化
│   ├── CPU
│   ├── 内存
│   └── 存储
├── 配置优化
│   ├── JVM
│   └── 系统参数
├── 索引优化
│   ├── 映射设计
│   └── 分片策略
└── 查询优化
    ├── 查询语法
    └── 缓存策略

CPU建议
├── 核心数
│   └── 8-64核
├── 主频
│   └── 越高越好
├── 使用场景
│   ├── 写入密集：更多核心
│   └── 查询密集：更高主频
└── 避免超线程
    └── 关闭或谨慎使用

内存建议
├── 堆内存
│   ├── 最大32GB
│   ├── 不超过物理内存50%
│   └── Xms=Xmx
├── 系统内存
│   └── 留给Lucene缓存
└── 内存锁定
    └── bootstrap.memory_lock: true

存储建议
├── 类型
│   ├── SSD（推荐）
│   └── NVMe（最佳）
├── IOPS
│   └── 越高越好
├── 避免使用
│   ├── NAS
│   └── 网络存储
└── RAID
    └── RAID0（性能）或RAID10（安全）

-Xms16g
-Xmx16g

-XX:+UseG1GC
-XX:G1HeapRegionSize=32m
-XX:InitiatingHeapOccupancyPercent=30
-XX:+HeapDumpOnOutOfMemoryError
-XX:HeapDumpPath=/var/log/elasticsearch/heapdump.hprof

-XX:+AlwaysPreTouch
-XX:+UseCompressedOops
-XX:+UseCompressedClassPointers
-Djava.io.tmpdir=/tmp
-XX:+ExitOnOutOfMemoryError

ulimit -n 65536

elasticsearch soft nofile 65536
elasticsearch hard nofile 65536

sysctl -w vm.max_map_count=262144

vm.max_map_count=262144

swapoff -a

echo never > /sys/kernel/mm/transparent_hugepage/enabled
echo never > /sys/kernel/mm/transparent_hugepage/defrag

PUT /products
{
  "mappings": {
    "properties": {
      "title": {
        "type": "text",
        "norms": false,
        "index_options": "freqs"
      },
      "status": {
        "type": "keyword",
        "doc_values": true
      },
      "price": {
        "type": "scaled_float",
        "scaling_factor": 100
      }
    }
  }
}

分片优化
├── 主分片数量
│   ├── 单分片10-50GB
│   └── 考虑扩展性
├── 副本数量
│   ├── 生产至少1个
│   └── 根据查询负载调整
└── 分片分布
    └── 均衡分布到节点

PUT /products/_settings
{
  "index": {
    "refresh_interval": "-1",
    "number_of_replicas": 0
  }
}

PUT /products/_settings
{
  "index": {
    "refresh_interval": "1s",
    "number_of_replicas": 1
  }
}

POST /products/_forcemerge?max_num_segments=1

GET /products/_search
{
  "query": {
    "bool": {
      "must": [
        { "match": { "name": "iPhone" } }
      ],
      "filter": [
        { "term": { "brand": "Apple" } },
        { "range": { "price": { "lte": 1000 } } }
      ]
    }
  }
}

GET /products/_search
{
  "size": 10,
  "query": { "match_all": {} },
  "sort": [
    { "created_at": "asc" },
    { "_id": "asc" }
  ],
  "search_after": ["2024-01-01", "abc123"]
}

GET /products/_search
{
  "query": { "match_all": {} },
  "_source": ["name", "price"]
}

GET /products/_search?routing=apple
{
  "query": {
    "match": { "name": "iPhone" }
  }
}

POST /products/_cache/clear

POST /products/_forcemerge?max_num_segments=1

PUT /products/_settings
{
  "index.queries.cache.enabled": true,
  "index.queries.cache.size": "10%"
}

PUT /_cluster/settings
{
  "persistent": {
    "indices.fielddata.cache.size": "40%"
  }
}

PUT /products/_settings
{
  "index.requests.cache.enable": true
}

POST /_bulk
{"index": {"_index": "products", "_id": "1"}}
{"name": "iPhone 15", "price": 999}

PUT /products/_settings
{
  "index": {
    "refresh_interval": "30s"
  }
}

PUT /products/_settings
{
  "index": {
    "translog": {
      "durability": "async",
      "sync_interval": "30s",
      "flush_threshold_size": "1gb"
    }
  }
}

GET /_nodes/stats

GET /_nodes/hot_threads

GET /_cat/indices?v&health=yellow

PUT /products/_settings
{
  "index.search.slowlog.threshold.query.warn": "10s",
  "index.search.slowlog.threshold.query.info": "5s",
  "index.search.slowlog.threshold.query.debug": "2s",
  "index.search.slowlog.threshold.fetch.warn": "1s"
}

PUT /products/_settings
{
  "index.indexing.slowlog.threshold.index.warn": "10s",
  "index.indexing.slowlog.threshold.index.info": "5s"
}

优化优先级
├── 1. 硬件优化
│   └── SSD、足够内存
├── 2. 索引设计
│   └── 合理映射和分片
├── 3. 查询优化
│   └── 使用filter、避免深度分页
├── 4. 配置优化
│   └── JVM、系统参数
└── 5. 缓存优化
    └── 合理使用缓存

性能测试建议
├── 基准测试
│   └── 建立性能基线
├── 压力测试
│   └── 测试极限性能
├── 对比测试
│   └── 优化前后对比
└── 持续监控
    └── 监控性能变化