ElasticSearch 集群黄色原因以及解决方案

# 原因1：
# ES采用默认配置（5分片，1副本），但实际我们本地是单机部署
$ curl -XGET 'http://localhost:9200/_cat/shards?v'
index shard prirep state      docs store ip            node
t1    2     p      STARTED       0  283b 172.19.209.98 node-1
t1    2     r      UNASSIGNED
t1    1     p      STARTED       0  283b 172.19.209.98 node-1
t1    1     r      UNASSIGNED
t1    3     p      STARTED       0  283b 172.19.209.98 node-1
t1    3     r      UNASSIGNED
t1    4     p      STARTED       0  283b 172.19.209.98 node-1
t1    4     r      UNASSIGNED
t1    0     p      STARTED       0  283b 172.19.209.98 node-1
t1    0     r      UNASSIGNED
t2    2     p      STARTED       0  230b 172.19.209.98 node-1
t2    2     r      UNASSIGNED
t2    1     p      STARTED       0  230b 172.19.209.98 node-1
t2    1     r      UNASSIGNED
t2    3     p      STARTED       0  230b 172.19.209.98 node-1
t2    3     r      UNASSIGNED
t2    4     p      STARTED       0  230b 172.19.209.98 node-1
t2    4     r      UNASSIGNED
t2    0     p      STARTED       0  230b 172.19.209.98 node-1
t2    0     r      UNASSIGNED

# 查看索引设置
GET http://localhost:9200/t2/_settings
{
  "t2": {
    "settings": {
      "index": {
        "creation_date": "1577030286504",
        "number_of_shards": "5",
        "number_of_replicas": "1",
        "uuid": "n_68GinmQtSfXZxb-aOjsQ",
        "version": {
          "created": "7050099"
        },
        "provided_name": "t2"
      }
    }
  }
}


# 修改副本
POST http://localhost:9200/t2/_settings
{
  "number_of_replicas": "0"
}


$ curl -XGET 'http://localhost:9200/_cat/shards?v'
index shard prirep state   docs store ip            node
t1    2     p      STARTED    0  283b 172.19.209.98 node-1
t1    1     p      STARTED    0  283b 172.19.209.98 node-1
t1    3     p      STARTED    0  283b 172.19.209.98 node-1
t1    4     p      STARTED    0  283b 172.19.209.98 node-1
t1    0     p      STARTED    0  283b 172.19.209.98 node-1
t2    2     p      STARTED    0  283b 172.19.209.98 node-1
t2    1     p      STARTED    0  283b 172.19.209.98 node-1
t2    3     p      STARTED    0  283b 172.19.209.98 node-1
t2    4     p      STARTED    0  283b 172.19.209.98 node-1
t2    0     p      STARTED    0  283b 172.19.209.98 node-1