Elasticsearch Alias

---

1.操作别名的两个方法：
_alias：单个操作
_aliases：多个操作，原子性的操作

2.创建别名

curl -XPUT 'localhost:9200/dm_v1/_alias/dm'
curl -XPOST 'http://localhost:9200/_aliases' -d '
{
    "actions" : [
        { "add" : { "index" : "dm_v1", "alias" : "dm_alias" } }
    ]
}'

3.删除别名

curl -XPOST 'http://localhost:9200/_aliases' -d '
{
    "actions" : [
        { "remove" : { "index" : "dm_v1", "alias" : "dm_alias" } }
    ]
}'
curl -XDELETE 'localhost:9200/dm_v1/_alias/dm_alias'

4.删除别名的同时添加别名到新的索引，该操作时原子性的，不用担心存在别名没有指向任何索引的瞬间

Renaming an alias is a simple remove then add operation within the same API. This operation is atomic, no need to worry about a short period of time where the alias does not point to an index:

curl -XPOST 'http://localhost:9200/_aliases' -d '
{
    "actions" : [
        { "remove" : { "index" : "dm_v1", "alias" : "dm" } },
        { "add" : { "index" : "dm_v2", "alias" : "dm" } }
    ]
}'

5.查询别名
通过别名查询所指向的索引：

curl -XGET 'localhost:9200/_alias/dm'
curl -XGET 'localhost:9200/_alias/dm*'

查询指向该索引下的所有别名：

curl -XGET 'localhost:9200/dm_v2/_alias/*'

6.也可以通过head检测别名是否存在

curl -XHEAD -i 'localhost:9200/_alias/dm'
curl -XHEAD -i 'localhost:9200/_alias/dm*'
curl -XHEAD -i 'localhost:9200/dm_v2/_alias/*'