ElasticSearch查看已经存在的文档保存在哪个分片


比如我有以下的文档:
{
"took" : 3,
"timed_out" : false,
"_shards" : {
"total" : 5,
"successful" : 5,
"skipped" : 0,
"failed" : 0
},
"hits" : {
"total" : 5,
"max_score" : 1.0,
"hits" : [
{
"_index" : "test",
"_type" : "mydoc",
"_id" : "XxyrM2kBVzdNcvl_GHv2",
"_score" : 1.0,
"_source" : {
"name" : "Shiled",
"twitter" : "Sonny sql is awesome",
"date" : "2018-12-27",
"id" : 1240,
"tags" : [
"red",
"shit"
]
}
},
{
"_index" : "test",
"_type" : "mydoc",
"_id" : "YByrM2kBVzdNcvl_tnvm",
"_score" : 1.0,
"_source" : {
"name" : "YYerk",
"twitter" : "sql is awesome",
"date" : "2008-12-27",
"id" : 12357,
"tags" : [
"red"
]
}
},
{
"_index" : "test",
"_type" : "mydoc",
"_id" : "7777",
"_score" : 1.0,
"_source" : {
"name" : "Rocky Chen",
"twitter" : "sql is awesome",
"date" : "2008-12-27",
"id" : 9999
}
},
{
"_index" : "test",
"_type" : "mydoc",
"_id" : "YhzDN2kBVzdNcvl_enuT",
"_score" : 1.0,
"_source" : {
"name" : "YYerk",
"twitter" : "sql is awesome",
"date" : "2008-12-27",
"id" : 888888,
"tags" : [
"red",
"green"
]
}
},
{
"_index" : "test",
"_type" : "mydoc",
"_id" : "YxzDN2kBVzdNcvl_u3th",
"_score" : 1.0,
"_source" : {
"name" : "YYerk",
"twitter" : "sql is awesome",
"date" : "2008-12-27",
"id" : 888888,
"tags" : [
"red",
"green"
]
}
}
]
}
}

如果我想看看id是  "_id" : "YxzDN2kBVzdNcvl_u3th",

这个文档是保存在哪个分片,如何查看?
 
引用:


 

路由一个文档到一个分片中编辑
当索引一个文档的时候,文档会被存储到一个主分片中。 Elasticsearch 如何知道一个文档应该存放到哪个分片中呢?当我们创建文档时,它如何决定这个文档应当被存储在分片 1 还是分片 2 中呢?
首先这肯定不会是随机的,否则将来要获取文档的时候我们就不知道从何处寻找了。实际上,这个过程是根据下面这个公式决定的:
shard = hash(routing) % number_of_primary_shards
routing 是一个可变值,默认是文档的 _id ,也可以设置成一个自定义的值。 routing 通过 hash 函数生成一个数字,然后这个数字再除以 number_of_primary_shards (主分片的数量)后得到 余数 。这个分布在 0 到 number_of_primary_shards-1 之间的余数,就是我们所寻求的文档所在分片的位置。
这就解释了为什么我们要在创建索引的时候就确定好主分片的数量 并且永远不会改变这个数量:因为如果数量变化了,那么所有之前路由的值都会无效,文档也再也找不到了。


 
那么可以使用

GET test/_search_shards?routing=ID号 来查看你要查询的id所在的分片

得到的结果:
{
"nodes" : {
"yl-qYmh1SXqzJsfI4d1ddw" : {
"name" : "node-3",
"ephemeral_id" : "UsJ9rFELTiCW07oHE9YMdg",
"transport_address" : "10.18.6.26:9300",
"attributes" : {
"ml.machine_memory" : "6088101888",
"rack" : "r1",
"ml.max_open_jobs" : "20",
"xpack.installed" : "true",
"ml.enabled" : "true"
}
},
"wT7wUd3iTkujYUsbVNVv-w" : {
"name" : "node-1",
"ephemeral_id" : "fP-vgSb0SdemnHDyaJUsWw",
"transport_address" : "10.18.6.102:9300",
"attributes" : {
"ml.machine_memory" : "8256720896",
"rack" : "r1",
"xpack.installed" : "true",
"ml.max_open_jobs" : "20",
"ml.enabled" : "true"
}
}
},
"indices" : {
"test" : { }
},
"shards" : [
[
{
"state" : "STARTED",
"primary" : true,
"node" : "wT7wUd3iTkujYUsbVNVv-w",
"relocating_node" : null,
"shard" : 1,
"index" : "test",
"allocation_id" : {
"id" : "k-8E4dL7QmGgwcsNsUCP6Q"
}
},
{
"state" : "STARTED",
"primary" : false,
"node" : "yl-qYmh1SXqzJsfI4d1ddw",
"relocating_node" : null,
"shard" : 1,
"index" : "test",
"allocation_id" : {
"id" : "lvOpQIKgRUibkulr3nRfEw"
}
}
]
]
}

只需要关注shards字段就可以,从上面可以看到,该文档存在shard 1 分片上。 分别在node1和node3节点,一个是主分片,一个是副本分片

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