一、問題源起
在elasticsearch的查詢中，我們一般直接通過URL來設定要search的index； 如果我們需要查詢的索引比較多並且沒有什麼規律的話，就會面臨一個尷尬的局面，超過URL的長度限制；
二、測試環境
elasticsearch 6.8.12
測試資料
新增三個測試的index，每個index裡邊一個document；
PUT test1/_doc/1
{
"id":1,
"name":"test1-1"
}
# {
# "_index" : "test1",
# "_type" : "_doc",
# "_id" : "1",
# "_version" : 1,
# "result" : "created",
# "_shards" : {
# "total" : 2,
# "successful" : 1,
# "failed" : 0
# },
# "_seq_no" : 0,
# "_primary_term" : 1
# }
PUT test2/_doc/1
{
"id":1,
"name":"test2-1"
}
# {
# "_index" : "test2",
# "_type" : "_doc",
# "_id" : "1",
# "_version" : 1,
# "result" : "created",
# "_shards" : {
# "total" : 2,
# "successful" : 1,
# "failed" : 0
# },
# "_seq_no" : 0,
# "_primary_term" : 1
# }
PUT test3/_doc/1
{
"id":1,
"name":"test3-1"
}
# {
# "_index" : "test3",
# "_type" : "_doc",
# "_id" : "1",
# "_version" : 1,
# "result" : "created",
# "_shards" : {
# "total" : 2,
# "successful" : 1,
# "failed" : 0
# },
# "_seq_no" : 0,
# "_primary_term" : 1
# }
三、URL中指定multi index
直接在URL中指定搜尋特定的index
POST test1/_search
{
"query": {
"match_all": {}
}
}
# {
# "took" : 0,
# "timed_out" : false,
# "_shards" : {
# "total" : 5,
# "successful" : 5,
# "skipped" : 0,
# "failed" : 0
# },
# "hits" : {
# "total" : 1,
# "max_score" : 1.0,
# "hits" : [
# {
# "_index" : "test1",
# "_type" : "_doc",
# "_id" : "1",
# "_score" : 1.0,
# "_source" : {
# "id" : 1,
# "name" : "test1-1"
# }
# }
# ]
# }
# }
可以通過都好分割同時搜尋多個index；
POST test1,test2/_search
{
"query": {
"match_all": {}
}
}
# {
# "took" : 1,
# "timed_out" : false,
# "_shards" : {
# "total" : 10,
# "successful" : 10,
# "skipped" : 0,
# "failed" : 0
# },
# "hits" : {
# "total" : 2,
# "max_score" : 1.0,
# "hits" : [
# {
# "_index" : "test1",
# "_type" : "_doc",
# "_id" : "1",
# "_score" : 1.0,
# "_source" : {
# "id" : 1,
# "name" : "test1-1"
# }
# },
# {
# "_index" : "test2",
# "_type" : "_doc",
# "_id" : "1",
# "_score" : 1.0,
# "_source" : {
# "id" : 1,
# "name" : "test2-1"
# }
# }
# ]
# }
# }
我們可以使用關鍵字_all指定搜尋所有的index；
POST _all/_search
{
"query": {
"match_all": {}
}
}
{
# "took" : 0,
# "timed_out" : false,
# "_shards" : {
# "total" : 15,
# "successful" : 15,
# "skipped" : 0,
# "failed" : 0
# },
# "hits" : {
# "total" : 3,
# "max_score" : 1.0,
# "hits" : [
# {
# "_index" : "test1",
# "_type" : "_doc",
# "_id" : "1",
# "_score" : 1.0,
# "_source" : {
# "id" : 1,
# "name" : "test1-1"
# }
# },
# {
# "_index" : "test2",
# "_type" : "_doc",
# "_id" : "1",
# "_score" : 1.0,
# "_source" : {
# "id" : 1,
# "name" : "test2-1"
# }
# },
# {
# "_index" : "test3",
# "_type" : "_doc",
# "_id" : "1",
# "_score" : 1.0,
# "_source" : {
# "id" : 1,
# "name" : "test3-1"
# }
# }
# ]
# }
# }
也可以使用萬用字元*來匹配一些名字有共同特徵的index；
POST test*/_search
{
"query": {
"match_all": {}
}
}
# {
# "took" : 1,
# "timed_out" : false,
# "_shards" : {
# "total" : 15,
# "successful" : 15,
# "skipped" : 0,
# "failed" : 0
# },
# "hits" : {
# "total" : 3,
# "max_score" : 1.0,
# "hits" : [
# {
# "_index" : "test1",
# "_type" : "_doc",
# "_id" : "1",
# "_score" : 1.0,
# "_source" : {
# "id" : 1,
# "name" : "test1-1"
# }
# },
# {
# "_index" : "test2",
# "_type" : "_doc",
# "_id" : "1",
# "_score" : 1.0,
# "_source" : {
# "id" : 1,
# "name" : "test2-1"
# }
# },
# {
# "_index" : "test3",
# "_type" : "_doc",
# "_id" : "1",
# "_score" : 1.0,
# "_source" : {
# "id" : 1,
# "name" : "test3-1"
# }
# }
# ]
# }
# }
還可以使用-來排除某個index；
POST test*,-test2/_search
{
"query": {
"match_all": {}
}
}
# {
# "took" : 0,
# "timed_out" : false,
# "_shards" : {
# "total" : 10,
# "successful" : 10,
# "skipped" : 0,
# "failed" : 0
# },
# "hits" : {
# "total" : 2,
# "max_score" : 1.0,
# "hits" : [
# {
# "_index" : "test1",
# "_type" : "_doc",
# "_id" : "1",
# "_score" : 1.0,
# "_source" : {
# "id" : 1,
# "name" : "test1-1"
# }
# },
# {
# "_index" : "test3",
# "_type" : "_doc",
# "_id" : "1",
# "_score" : 1.0,
# "_source" : {
# "id" : 1,
# "name" : "test3-1"
# }
# }
# ]
# }
# }
四、URL中multi index的一些控制選項
如果我們顯示search一個不存在的或者關閉的index就會報錯；
POST test4/_search
{
"query": {
"match_all": {}
}
}
# {
# "error" : {
# "root_cause" : [
# {
# "type" : "index_not_found_exception",
# "reason" : "no such index",
# "resource.type" : "index_or_alias",
# "resource.id" : "test4",
# "index_uuid" : "_na_",
# "index" : "test4"
# }
# ],
# "type" : "index_not_found_exception",
# "reason" : "no such index",
# "resource.type" : "index_or_alias",
# "resource.id" : "test4",
# "index_uuid" : "_na_",
# "index" : "test4"
# },
# "status" : 404
# }
POST test3/_close
#
# {
# "acknowledged" : true
# }
POST test3/_search
{
"query": {
"match_all": {}
}
}
# {
# "error": {
# "root_cause": [
# {
# "type": "index_closed_exception",
# "reason": "closed",
# "index_uuid": "KI7Iv4eGRIOk6MsycXokNQ",
# "index": "test3"
# }
# ],
# "type": "index_closed_exception",
# "reason": "closed",
# "index_uuid": "KI7Iv4eGRIOk6MsycXokNQ",
# "index": "test3"
# },
# "status": 400
# }
我們可以使用ignore_unavailable來忽略不存在或者關閉的index；
POST test4/_search?ignore_unavailable=true
{
"query": {
"match_all": {}
}
}
# {
# "took" : 0,
# "timed_out" : false,
# "_shards" : {
# "total" : 0,
# "successful" : 0,
# "skipped" : 0,
# "failed" : 0
# },
# "hits" : {
# "total" : 0,
# "max_score" : 0.0,
# "hits" : [ ]
# }
# }
POST test3/_search?ignore_unavailable=true
{
"query": {
"match_all": {}
}
}
# {
# "took" : 0,
# "timed_out" : false,
# "_shards" : {
# "total" : 0,
# "successful" : 0,
# "skipped" : 0,
# "failed" : 0
# },
# "hits" : {
# "total" : 0,
# "max_score" : 0.0,
# "hits" : [ ]
# }
# }
如果通過萬用字元、_all隱式的指定search的index，如果不存在則預設不會報錯，不過可以通過allow_no_indices=false來讓elasticsearch報錯；
POST noexist*/_search
{
"query": {
"match_all": {}
}
}
# {
# "took" : 0,
# "timed_out" : false,
# "_shards" : {
# "total" : 0,
# "successful" : 0,
# "skipped" : 0,
# "failed" : 0
# },
# "hits" : {
# "total" : 0,
# "max_score" : 0.0,
# "hits" : [ ]
# }
# }
POST noexist*/_search?allow_no_indices=false
{
"query": {
"match_all": {}
}
}
# {
# "error" : {
# "root_cause" : [
# {
# "type" : "index_not_found_exception",
# "reason" : "no such index",
# "resource.type" : "index_or_alias",
# "resource.id" : "noexist*",
# "index_uuid" : "_na_",
# "index" : "noexist*"
# }
# ],
# "type" : "index_not_found_exception",
# "reason" : "no such index",
# "resource.type" : "index_or_alias",
# "resource.id" : "noexist*",
# "index_uuid" : "_na_",
# "index" : "noexist*"
# },
# "status" : 404
# }
POST test3*/_search
{
"query": {
"match_all": {}
}
}
# {
# "took" : 0,
# "timed_out" : false,
# "_shards" : {
# "total" : 0,
# "successful" : 0,
# "skipped" : 0,
# "failed" : 0
# },
# "hits" : {
# "total" : 0,
# "max_score" : 0.0,
# "hits" : [ ]
# }
# }
POST test3*/_search?allow_no_indices=false
{
"query": {
"match_all": {}
}
}
# {
# "error" : {
# "root_cause" : [
# {
# "type" : "index_not_found_exception",
# "reason" : "no such index",
# "resource.type" : "index_or_alias",
# "resource.id" : "test3*"
# }
# ],
# "type" : "index_not_found_exception",
# "reason" : "no such index",
# "resource.type" : "index_or_alias",
# "resource.id" : "test3*"
# },
# "status" : 404
# }
我們也可以使用expand_wildcards來控制展開哪些index，可選值open、closed、none、all；
預設只擴充套件open；
POST test*/_search
{
"query": {
"match_all": {}
}
}
# {
# "took" : 0,
# "timed_out" : false,
# "_shards" : {
# "total" : 10,
# "successful" : 10,
# "skipped" : 0,
# "failed" : 0
# },
# "hits" : {
# "total" : 2,
# "max_score" : 1.0,
# "hits" : [
# {
# "_index" : "test1",
# "_type" : "_doc",
# "_id" : "1",
# "_score" : 1.0,
# "_source" : {
# "id" : 1,
# "name" : "test1-1"
# }
# },
# {
# "_index" : "test2",
# "_type" : "_doc",
# "_id" : "1",
# "_score" : 1.0,
# "_source" : {
# "id" : 1,
# "name" : "test2-1"
# }
# }
# ]
# }
# }
POST test*/_search?expand_wildcards=all
{
"query": {
"match_all": {}
}
}
# {
# "error": {
# "root_cause": [
# {
# "type": "index_closed_exception",
# "reason": "closed",
# "index_uuid": "KI7Iv4eGRIOk6MsycXokNQ",
# "index": "test3"
# }
# ],
# "type": "index_closed_exception",
# "reason": "closed",
# "index_uuid": "KI7Iv4eGRIOk6MsycXokNQ",
# "index": "test3"
# },
# "status": 400
# }
POST test*/_search?expand_wildcards=all&ignore_unavailable=true
{
"query": {
"match_all": {}
}
}
# {
# "took" : 0,
# "timed_out" : false,
# "_shards" : {
# "total" : 10,
# "successful" : 10,
# "skipped" : 0,
# "failed" : 0
# },
# "hits" : {
# "total" : 2,
# "max_score" : 1.0,
# "hits" : [
# {
# "_index" : "test1",
# "_type" : "_doc",
# "_id" : "1",
# "_score" : 1.0,
# "_source" : {
# "id" : 1,
# "name" : "test1-1"
# }
# },
# {
# "_index" : "test2",
# "_type" : "_doc",
# "_id" : "1",
# "_score" : 1.0,
# "_source" : {
# "id" : 1,
# "name" : "test2-1"
# }
# }
# ]
# }
# }
五、使用index aliases封裝物理index
aliases是物理索引的別名，請求api的時候，elasticsearch會自動將aliases轉化為對應的物理index name；
別名既可以對映到某個特定的index，也可以對映到多個index；
別名也可以同時應用過濾條件，實現只對index的區域性資料進行搜尋；
POST /_aliases
{
"actions" : [
{ "add" : { "index" : "test*", "alias" : "all_test_indices" } }
]
}
# {
# "acknowledged" : true
# }
POST all_test_indices/_search
{
"query": {
"match_all": {}
}
}
# {
# "took" : 0,
# "timed_out" : false,
# "_shards" : {
# "total" : 10,
# "successful" : 10,
# "skipped" : 0,
# "failed" : 0
# },
# "hits" : {
# "total" : 2,
# "max_score" : 1.0,
# "hits" : [
# {
# "_index" : "test1",
# "_type" : "_doc",
# "_id" : "1",
# "_score" : 1.0,
# "_source" : {
# "id" : 1,
# "name" : "test1-1"
# }
# },
# {
# "_index" : "test2",
# "_type" : "_doc",
# "_id" : "1",
# "_score" : 1.0,
# "_source" : {
# "id" : 1,
# "name" : "test2-1"
# }
# }
# ]
# }
# }
六、multi search--通過body指定index
Multi Search API的主要目的是實現在一個API裡邊實現多個search請求，其通過如下格式分別通過header指定index，body指定查詢語句；
header\n
body\n
header\n
body\n
Multi Search API除了與前兩者具有相同的指定index name的能力，最大的優勢就是通過body傳遞index name，輕鬆突破URL的長度限制的侷限性；
還有一點就是Multi Search API支援大量的沒有特定規律的index name，例如跟時間序列有關的index name等；
GET _msearch
{"index":"test*"}
{"query" : {"match_all" : {}}}
# {
# "responses" : [
# {
# "took" : 0,
# "timed_out" : false,
# "_shards" : {
# "total" : 10,
# "successful" : 10,
# "skipped" : 0,
# "failed" : 0
# },
# "hits" : {
# "total" : 2,
# "max_score" : 1.0,
# "hits" : [
# {
# "_index" : "test1",
# "_type" : "_doc",
# "_id" : "1",
# "_score" : 1.0,
# "_source" : {
# "id" : 1,
# "name" : "test1-1"
# }
# },
# {
# "_index" : "test2",
# "_type" : "_doc",
# "_id" : "1",
# "_score" : 1.0,
# "_source" : {
# "id" : 1,
# "name" : "test2-1"
# }
# }
# ]
# },
# "status" : 200
# }
# ]
# }