elasticsearch 7.6 移除数据节点

r囧r小猫 2022-09-03 00:16 247阅读 0赞

os: centos 7.6  
es: 7.6

上一篇 blog <<[elasticsearch 7.6 添加数据节点][elasticsearch 7.6]>>介绍了添加数据节点，  
这篇 blog 介绍下移除数据节点。

# 版本 #

# cat /etc/centos-release
    CentOS Linux release 7.6.1810 (Core)
    
    # yum list installed |grep -i elasticsearch
    elasticsearch.x86_64               7.6.2-1                             installed
    
    
    # cat /etc/hosts
    127.0.0.1   localhost localhost.localdomain localhost4 localhost4.localdomain4
    ::1         localhost localhost.localdomain localhost6 localhost6.localdomain6
    
    192.168.56.211  n1
    192.168.56.212  n2
    192.168.56.213  n3
    192.168.56.214  n4

# 实际操作 #

节点数目少的时候，**一定要注意脑裂问题**。

移除节点  
执行命令后，es 开始该节点上的分片分配给其余节点(**高度消耗io**)

# curl -X PUT 'http://192.168.56.211:9200/_cluster/settings' -H 'Content-Type: application/json' -d ' 
    {
        "transient" : {
            "cluster.routing.allocation.enable" : "all"
        }
    }
    '
    
    # curl -X PUT 'http://192.168.56.211:9200/_cluster/settings' -H 'Content-Type: application/json' -d ' 
    {
        "transient" : {
            "cluster.routing.allocation.exclude._ip" : "192.168.56.214"
        }
    }
    '

查看 集群、节点信息

# curl -X GET 'http://192.168.56.211:9200/_cluster/health?pretty' 
    {
      "cluster_name" : "my-application",
      "status" : "green",
      "timed_out" : false,
      "number_of_nodes" : 4,
      "number_of_data_nodes" : 4,
      "active_primary_shards" : 64,
      "active_shards" : 192,
      "relocating_shards" : 0,
      "initializing_shards" : 0,
      "unassigned_shards" : 0,
      "delayed_unassigned_shards" : 0,
      "number_of_pending_tasks" : 0,
      "number_of_in_flight_fetch" : 0,
      "task_max_waiting_in_queue_millis" : 0,
      "active_shards_percent_as_number" : 100.0
    }

# curl -X GET 'http://192.168.56.211:9200/_cat/health?v'
    epoch      timestamp cluster        status node.total node.data shards pri relo init unassign pending_tasks max_task_wait_time active_shards_percent
    1628061838 07:23:58  my-application green           4         4    192  64    0    0        0             0                  -                100.0%

# curl -X GET 'http://192.168.56.211:9200/_cat/nodes?v' 
    
    ip             heap.percent ram.percent cpu load_1m load_5m load_15m node.role master name
    192.168.56.214            9          99   1    0.02    0.09     0.08 dil       -      node-4
    192.168.56.212           25          99   0    0.37    0.54     0.40 dilm      *      node-2
    192.168.56.211           21          99   1    0.05    0.23     0.16 dilm      -      node-1
    192.168.56.213           20          99   0    0.28    0.23     0.17 dilm      -      node-3

可以看到 node-4 已无数据  
![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2N0eXB5YjIwMDI_size_16_color_FFFFFF_t_70]

记得n1、n2、n3 节点的 discovery.seed\_hosts 值也检查、修改下。

参考:

[elasticsearch 7.6]: https://ctypyb2002.blog.csdn.net/article/details/119381513
[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2N0eXB5YjIwMDI_size_16_color_FFFFFF_t_70]: /images/20220829/e93e3f99363549d085c1dff3c4d175c5.png