Profile API · Elasticsearch 5.4 中文文檔

# Profile API 原文鏈接 : [https://www.elastic.co/guide/en/elasticsearch/reference/current/search-profile.html](https://www.elastic.co/guide/en/elasticsearch/reference/current/search-profile.html) 譯文鏈接 : [Profile API](/display/Elasticsearch/Profile+API) 貢獻者 : [王晗](/display/~wanghan) ?此功能是實驗性功能，可能在未來的版本中完全更改或刪除。 Profile API提供了在搜索請求中執行單個組件的詳細時間信息。它讓用戶了解在底層如何執行搜索請求，這樣用戶可以理解為什么某些請求是緩慢的，并采取措施改善他們。 Profile API的輸出**非常**詳細，特別是對于跨多個分片的復雜請求執行。推薦使用pretty打印響應信息，這樣有助于理解輸出結果。 ## 用法/Usage 任意__search_請求可以通過添加一個頂級_profile_參數來實現概要描述。 ``` curl -XGET 'localhost:9200/_search?pretty' -H 'Content-Type: application/json' -d' { "profile": true,?（1） "query" : { "match" : { "message" : "message number" } } } ' ``` （1）?設置頂級profile參數為true，開啟搜索概要描述這將產生以下結果： ``` ?{ "took": 25, "timed_out": false, "_shards": { "total": 1, "successful": 1, "failed": 0 }, "hits": { "total": 4, "max_score": 0.5093388, "hits": [...] }, "profile": { "shards": [ { "id": "[2aE02wS1R8q_QFnYu6vDVQ][twitter][1]", "searches": [ { "query": [ { "type": "BooleanQuery", "description": "message:message message:number", "time": "1.873811000ms", "time_in_nanos": "1873811", "breakdown": { "score": 51306, "score_count": 4, "build_scorer": 2935582, "build_scorer_count": 1, "match": 0, "match_count": 0, "create_weight": 919297, "create_weight_count": 1, "next_doc": 53876, "next_doc_count": 5, "advance": 0, "advance_count": 0 }, "children": [ { "type": "TermQuery", "description": "message:message", "time": "0.3919430000ms", "time_in_nanos": "391943", "breakdown": { "score": 28776, "score_count": 4, "build_scorer": 784451, "build_scorer_count": 1, "match": 0, "match_count": 0, "create_weight": 1669564, "create_weight_count": 1, "next_doc": 10111, "next_doc_count": 5, "advance": 0, "advance_count": 0 } }, { "type": "TermQuery", "description": "message:number", "time": "0.2106820000ms", "time_in_nanos": "210682", "breakdown": { "score": 4552, "score_count": 4, "build_scorer": 42602, "build_scorer_count": 1, "match": 0, "match_count": 0, "create_weight": 89323, "create_weight_count": 1, "next_doc": 2852, "next_doc_count": 5, "advance": 0, "advance_count": 0 } } ] } ], "rewrite_time": 51443, "collector": [ { "name": "CancellableCollector", "reason": "search_cancelled", "time": "0.3043110000ms", "time_in_nanos": "304311", "children": [ { "name": "SimpleTopScoreDocCollector", "reason": "search_top_hits", "time": "0.03227300000ms", "time_in_nanos": "32273" } ] } ] } ], "aggregations": [] } ] } } ``` （1）返回的搜索結果，為簡便起見，這里省略即使對于一個簡單的查詢，響應過程也是相對復雜的。在深入更復雜的例子之前，讓我們先全面剖析它。首先，profile響應的整體結構如下: ``` { "profile": { "shards": [ { "id": "[2aE02wS1R8q_QFnYu6vDVQ][twitter][1]", (1) "searches": [ { "query": [...], (2) "rewrite_time": 51443, (3) "collector": [...] (4) } ], "aggregations": [...] (5) } ] } } ``` | (1)profile返回參與響應的每一個分片，這些分片由唯一ID標識 | | (2)每個概要都包含關于查詢執行的詳細信息部分 | | (3)每個概要都有一個單獨的rewrite_time累計時間。 | | (4)每個概要還包含關于運行搜索的lucene Collector部分 | | (5)每個概要都包含有關聚合執行的詳細信息部分 | 因為一個搜索請求可能在一個或多個索引分片上執行，并且搜索范圍覆蓋一個或多個索引，profile的響應中頂層元素是一個shard對象數組。每個分片對象列表都列出唯一標識分片的id。ID的格式是[nodeID][indexName][shardID] profile本身可能包含一個或多個"searches"字段，其中每個搜索search是針對底層Lucene索引執行的查詢。用戶提交的大多數搜索請求只會執行對Lucene索引的一個search。但偶爾也會執行多個搜索searches，如包括全局聚合(這需要執行第二個“match_all”查詢全局上下文)。在每個搜索對象里，會有兩個概要信息的數組：query?數組和collector?數組。與搜索對象并肩的是一個聚合aggregations?對象，它包含聚合的概要信息。在未來，可以添加更多的部分，如建議?suggest，高亮highlight等。這也會有一個rewrite?度量顯示重寫查詢的總時間 (以納秒為單位)。