opensearch基础

1. Cluster

   • Contains one or more nodes
   • Managed by a master node

2. Node

   • Single server part of a cluster
   • Types: Master-eligible, data, ingest, etc.

3. Index

   • Collection of documents with similar characteristics
   • Managed by shards

4. Shard（分片）:

   OpenSearch 索引中的数据可以增长到巨大的比例。为了保持其可管理性，它被拆分为多个分片。每个 OpenSearch 分片都是一个 Apache Lucene 索引，每个单独的 Lucene 索引都包含 OpenSearch 索引中文档的子集。以这种方式拆分索引可以控制资源使用。Apache Lucene 索引的文档数量限制为 2,147,483,519 个。

   • Single Lucene instance
   • Holds part of an index's data
   • Types: Primary and replica

5. Document

   • Basic unit of information
   • Expressed in JSON format

6. Field

   • Smallest individual unit of data in a document
   • Has a defined datatype

7. Mapping

   • Defines how a document and its fields are stored and indexed （定义文档及其字段的存储和索引方式）

8. Segment （段）

   • An inverted index （倒排索引）
   • Created when a new document is indexed （在为新文档编制索引时创建）
   • Merged into larger segments over time

如果安装的opensearch是集群，那么每个node节点都需要安装插件

opensearch安装分词插件

#进入docker容器
docker exec -it opensearch-node1 bash

1. 安装opensearch提供的分词插件（analysis-smartcn）

   #进入容器后，执行以下命令
   bin/opensearch-plugin install analysis-smartcn
   

2. 通过压缩包安装插件

   #file:///opensearch-analysis-ik.zip 为压缩文件在容器中的位置
   bin/opensearch-plugin install file:///opensearch-analysis-ik.zip
   

安装IK分词器启动opensearch服务的报错：

1. NoClassDefFoundError: org/apache/commons/logging/LogFactory

   #缺少jar包，下载commons-logging-1.2.jar后复制到对应的目录（opensearch-node1为容器的名称）
   docker cp /data/openSearch/commons-logging-1.2.jar opensearch-node1:/usr/share/opensearch/plugins/opensearch-analysis-ik
   

2. 分词插入数据时报错空指针 org.wltea.analyzer.dic.Dictionary.singleton._StopWords;

   #进入docker容器
   docker exec -it opensearch-node1 bash
   #查看/usr/share/opensearch/plugins/opensearch-analysis-ik/config是否存在，如果不存在的话
   cd /usr/share/opensearch/plugins/opensearch-analysis-ik
   mkdir config
   chmod 755
   #将opensearch-analysis-ik目录下的所有文件复制到config目录
   cp -r /usr/share/opensearch/config/opensearch-analysis-ik/* /usr/share/opensearch/plugins/opensearch-analysis-ik/config
   

3. #本地通过 find 命令查找文件
   find / -name "sonar-pmd-plugin-2.6.jar"
   

其他操作：

#本地通过 find 命令查找文件
find / -name "sonar-pmd-plugin-2.6.jar"

#修改IKAnalyzer.cfg.xml来设置自定义分词
docker cp /data/openSearch/IKAnalyzer.cfg.xml opensearch-node1:/usr/share/opensearch/plugins/opensearch-analysis-ik/config

opensarch集群的docker-compose文件：

version: '3'
services:
  opensearch-node1:
    image: opensearchproject/opensearch:latest
    container_name: opensearch-node1
    environment:
      - cluster.name=opensearch-cluster # Name the cluster
      - node.name=opensearch-node1 # Name the node that will run in this container
      - discovery.seed_hosts=opensearch-node1,opensearch-node2 # Nodes to look for when discovering the cluster
      - cluster.initial_cluster_manager_nodes=opensearch-node1,opensearch-node2 # Nodes eligibile to serve as cluster manager
      - bootstrap.memory_lock=true # Disable JVM heap memory swapping
      - "OPENSEARCH_JAVA_OPTS=-Xms512m -Xmx512m" # Set min and max JVM heap sizes to at least 50% of system RAM
      - "DISABLE_INSTALL_DEMO_CONFIG=true" # Prevents execution of bundled demo script which installs demo certificates and security configurations to OpenSearch
      - "DISABLE_SECURITY_PLUGIN=true" # Disables Security plugin
    ulimits:
      memlock:
        soft: -1 # Set memlock to unlimited (no soft or hard limit)
        hard: -1
      nofile:
        soft: 65536 # Maximum number of open files for the opensearch user - set to at least 65536
        hard: 65536
    volumes:
      - opensearch-data1:/usr/share/opensearch/data # Creates volume called opensearch-data1 and mounts it to the container
    ports:
      - 9200:9200 # REST API
      - 9300:9300 # TCP API
      - 9600:9600 # Performance Analyzer
    networks:
      - opensearch-net # All of the containers will join the same Docker bridge network
  opensearch-node2:
    image: opensearchproject/opensearch:latest
    container_name: opensearch-node2
    environment:
      - cluster.name=opensearch-cluster # Name the cluster
      - node.name=opensearch-node2 # Name the node that will run in this container
      - discovery.seed_hosts=opensearch-node1,opensearch-node2 # Nodes to look for when discovering the cluster
      - cluster.initial_cluster_manager_nodes=opensearch-node1,opensearch-node2 # Nodes eligibile to serve as cluster manager
      - bootstrap.memory_lock=true # Disable JVM heap memory swapping
      - "OPENSEARCH_JAVA_OPTS=-Xms512m -Xmx512m" # Set min and max JVM heap sizes to at least 50% of system RAM
      - "DISABLE_INSTALL_DEMO_CONFIG=true" # Prevents execution of bundled demo script which installs demo certificates and security configurations to OpenSearch
      - "DISABLE_SECURITY_PLUGIN=true" # Disables Security plugin
    ulimits:
      memlock:
        soft: -1 # Set memlock to unlimited (no soft or hard limit)
        hard: -1
      nofile:
        soft: 65536 # Maximum number of open files for the opensearch user - set to at least 65536
        hard: 65536
    volumes:
      - opensearch-data2:/usr/share/opensearch/data # Creates volume called opensearch-data2 and mounts it to the container
    networks:
      - opensearch-net # All of the containers will join the same Docker bridge network
  opensearch-dashboards:
    image: opensearchproject/opensearch-dashboards:latest
    container_name: opensearch-dashboards
    ports:
      - 5601:5601 # Map host port 5601 to container port 5601
    expose:
      - "5601" # Expose port 5601 for web access to OpenSearch Dashboards
    environment:
      - 'OPENSEARCH_HOSTS=["http://opensearch-node1:9200","http://opensearch-node2:9200"]'
      - "DISABLE_SECURITY_DASHBOARDS_PLUGIN=true" # disables security dashboards plugin in OpenSearch Dashboards
    networks:
      - opensearch-net

volumes:
  opensearch-data1:
  opensearch-data2:

networks:
  opensearch-net: