ES集群概念
elasticsearch集群就是由一个或多个节点组织在一起,它们共同持有整个的数据,并一起提供索引和搜索功能,一个elasticsearch集群由一个唯一的名字标识,默认为:"elasticsearch"
分片
ES索引可能存储超过1T的数据,但是一个节点可能只有500G的空间,这个时候,ES集群可以通过分片方案,将文档分别存储到多个节点中.
ES提供了将索引划分多份的能力,这些份就是"分片"
在图中,节点1,2,3分别存储了索引index的 分片1,2,3,假设这个时候node2节点宕机了,会出现什么情况呢?
当node2节点宕机了,index索引存储的3个分片将剩下2个,就会导致整个索引无法使用,ES集群无法再提供服务
复制
为了避免这个问题,ES创建分片的一份或者多份拷贝,这些拷贝叫做 "复制分片",或者直接叫"复制"
当node2节点宕机之后,在node1中的复制分片将可以提供服务
集群搭建
我们需要准备3台服务器安装docker,没有3台的可以直接单机起3个容器
docker pull elasticsearch:8.5.2
增加文件句柄数,在/etc/sysctl.conf 新增一行
vm.max\_map\_count=262144 sysctl -p
docker-compose文件:
version: '2.2' services: es01: image: docker.elastic.co/elasticsearch/elasticsearch:8.5.2 container_name: es01 environment: - node.name=es01 - cluster.name=es-docker-cluster - discovery.seed_hosts=es02,es03 - cluster.initial\_master\_nodes=es01,es02,es03 - bootstrap.memory_lock=true - xpack.security.enabled=false - xpack.security.transport.ssl.enabled=false - "ES\_JAVA\_OPTS=-Xms512m -Xmx512m" ulimits: memlock: soft: -1 hard: -1 volumes: - data01:/usr/share/elasticsearch/data ports: - 9200:9200 networks: - elastic es02: image: docker.elastic.co/elasticsearch/elasticsearch:8.5.2 container_name: es02 environment: - node.name=es02 - cluster.name=es-docker-cluster - discovery.seed_hosts=es01,es03 - cluster.initial\_master\_nodes=es01,es02,es03 - bootstrap.memory_lock=true - "ES\_JAVA\_OPTS=-Xms512m -Xmx512m" - xpack.security.enabled=false - xpack.security.transport.ssl.enabled=false ulimits: memlock: soft: -1 hard: -1 volumes: - data02:/usr/share/elasticsearch/data networks: - elastic es03: image: docker.elastic.co/elasticsearch/elasticsearch:8.5.2 container_name: es03 environment: - node.name=es03 - cluster.name=es-docker-cluster - discovery.seed_hosts=es01,es02 - cluster.initial\_master\_nodes=es01,es02,es03 - bootstrap.memory_lock=true - xpack.security.enabled=false - xpack.security.transport.ssl.enabled=false - "ES\_JAVA\_OPTS=-Xms512m -Xmx512m" ulimits: memlock: soft: -1 hard: -1 volumes: - data03:/usr/share/elasticsearch/data networks: - elastic volumes: data01: driver: local data02: driver: local data03: driver: local networks: elastic: driver: bridge
运行docker-compose up -d即可
root@tioncico:~/elasticsearch# docker-compose up -d root@tioncico:~/elasticsearch# docker ps CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES 834e72d63235 docker.elastic.co/elasticsearch/elasticsearch:8.5.2 "/bin/tini -- /usr/l…" 12 seconds ago Up 4 seconds 9200/tcp, 9300/tcp es02 644bf94a5e48 docker.elastic.co/elasticsearch/elasticsearch:8.5.2 "/bin/tini -- /usr/l…" 12 seconds ago Up 4 seconds 0.0.0.0:9200->9200/tcp, :::9200->9200/tcp, 9300/tcp es01 8ae4ceab7226 docker.elastic.co/elasticsearch/elasticsearch:8.5.2 "/bin/tini -- /usr/l…" 12 seconds ago Up 4 seconds 9200/tcp, 9300/tcp es03 root@tioncico:~/elasticsearch#
如果运行失败的话,可以通过 docker logs es01 查看失败日志
节点测试:
root@tioncico:~/elasticsearch# curl -X PUT 127.0.0.1:9200/test {"acknowledged":true,"shards_acknowledged":true,"index":"test"}
