1，创建索引：

put blog
{
"settings":{
"number_of_shards":3,
"number_of_replicas":0
}
}

返回值为：
{
"acknowledged": true,
"shards_acknowledged": true,
"index": "blog"
}

注：

"number_of_shards": 分片数
"number_of_replicas":副本数

2，elastic 创建索引完成后分片数是不可修改的，但是副本数是可以修改的

put blog/_settings
{
"number_of_replicas":1
}
返回值是：
{
"acknowledged": true
}

3，elastic 对索引的读写操作的限制：

blocks.read_only:true

blocks.read:true

blocks.write:true

4,该索引添加别名：

post _aliases
{
    "actions":[
        {
            "add":{
                "index":"blog",
                "alias":"blog_alias"
            }
        }
    ]
}

返回值：

{
"acknowledged": true
}