opensearch-docs-cn/_api-reference/profile.md

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Profile

The Profile API provides timing information about the execution of individual components of a search request. Using the Profile API, you can debug slow requests and understand how to improve their performance. The Profile API does not measure the following:

  • Network latency
  • Time spent in the search fetch phase
  • Amount of time a request spends in queues
  • Idle time while merging shard responses on the coordinating node

The Profile API is a resource-consuming operation that adds overhead to search operations. {: .warning}

Example request

To use the Profile API, include the profile parameter set to true in the search request sent to the _search endpoint:

GET /testindex/_search
{
  "profile": true,
  "query" : {
    "match" : { "title" : "wind" }
  }
}

{% include copy-curl.html %}

To turn on human-readable format, include the ?human=true query parameter in the request:

GET /testindex/_search?human=true
{
  "profile": true,
  "query" : {
    "match" : { "title" : "wind" }
  }
}

{% include copy-curl.html %}

The response contains an additional time field with human-readable units, for example:

"collector": [
    {
        "name": "SimpleTopScoreDocCollector",
        "reason": "search_top_hits",
        "time": "113.7micros",
        "time_in_nanos": 113711
    }
]

The Profile API response is verbose, so if you're running the request through the curl command, include the ?pretty query parameter to make the response easier to understand. {: .tip}

Example response

The response contains profiling information:

Response {: .text-delta}
{
  "took": 21,
  "timed_out": false,
  "_shards": {
    "total": 1,
    "successful": 1,
    "skipped": 0,
    "failed": 0
  },
  "hits": {
    "total": {
      "value": 2,
      "relation": "eq"
    },
    "max_score": 0.19363807,
    "hits": [
      {
        "_index": "testindex",
        "_id": "1",
        "_score": 0.19363807,
        "_source": {
          "title": "The wind rises"
        }
      },
      {
        "_index": "testindex",
        "_id": "2",
        "_score": 0.17225474,
        "_source": {
          "title": "Gone with the wind",
          "description": "A 1939 American epic historical film"
        }
      }
    ]
  },
  "profile": {
    "shards": [
      {
        "id": "[LidyZ1HVS-u93-73Z49dQg][testindex][0]",
        "inbound_network_time_in_millis": 0,
        "outbound_network_time_in_millis": 0,
        "searches": [
          {
            "query": [
              {
                "type": "BooleanQuery",
                "description": "title:wind title:rise",
                "time_in_nanos": 2473919,
                "breakdown": {
                  "set_min_competitive_score_count": 0,
                  "match_count": 0,
                  "shallow_advance_count": 0,
                  "set_min_competitive_score": 0,
                  "next_doc": 5209,
                  "match": 0,
                  "next_doc_count": 2,
                  "score_count": 2,
                  "compute_max_score_count": 0,
                  "compute_max_score": 0,
                  "advance": 9209,
                  "advance_count": 2,
                  "score": 20751,
                  "build_scorer_count": 4,
                  "create_weight": 1404458,
                  "shallow_advance": 0,
                  "create_weight_count": 1,
                  "build_scorer": 1034292
                },
                "children": [
                  {
                    "type": "TermQuery",
                    "description": "title:wind",
                    "time_in_nanos": 813581,
                    "breakdown": {
                      "set_min_competitive_score_count": 0,
                      "match_count": 0,
                      "shallow_advance_count": 0,
                      "set_min_competitive_score": 0,
                      "next_doc": 3291,
                      "match": 0,
                      "next_doc_count": 2,
                      "score_count": 2,
                      "compute_max_score_count": 0,
                      "compute_max_score": 0,
                      "advance": 7208,
                      "advance_count": 2,
                      "score": 18666,
                      "build_scorer_count": 6,
                      "create_weight": 616375,
                      "shallow_advance": 0,
                      "create_weight_count": 1,
                      "build_scorer": 168041
                    }
                  },
                  {
                    "type": "TermQuery",
                    "description": "title:rise",
                    "time_in_nanos": 191083,
                    "breakdown": {
                      "set_min_competitive_score_count": 0,
                      "match_count": 0,
                      "shallow_advance_count": 0,
                      "set_min_competitive_score": 0,
                      "next_doc": 0,
                      "match": 0,
                      "next_doc_count": 0,
                      "score_count": 0,
                      "compute_max_score_count": 0,
                      "compute_max_score": 0,
                      "advance": 0,
                      "advance_count": 0,
                      "score": 0,
                      "build_scorer_count": 2,
                      "create_weight": 188625,
                      "shallow_advance": 0,
                      "create_weight_count": 1,
                      "build_scorer": 2458
                    }
                  }
                ]
              }
            ],
            "rewrite_time": 192417,
            "collector": [
              {
                "name": "SimpleTopScoreDocCollector",
                "reason": "search_top_hits",
                "time_in_nanos": 77291
              }
            ]
          }
        ],
        "aggregations": []
      }
    ]
  }
}

Response fields

The response includes the following fields.

Field Data type Description
profile Object Contains profiling information.
profile.shards Array of objects A search request can be executed against one or more shards in the index, and a search may involve one or more indexes. Thus, the profile.shards array contains profiling information for each shard that was involved in the search.
profile.shards.id String The shard ID of the shard in the [node-ID][index-name][shard-ID] format.
profile.shards.searches Array of objects A search represents a query executed against the underlying Lucene index. Most search requests execute a single search against a Lucene index, but some search requests can execute more than one search. For example, including a global aggregation results in a secondary match_all query for the global context. The profile.shards array contains profiling information about each search execution.
profile.shards.searches.query Array of objects Profiling information about the query execution.
profile.shards.searches.rewrite_time Integer All Lucene queries are rewritten. A query and its children may be rewritten more than once, until the query stops changing. The rewriting process involves performing optimizations, such as removing redundant clauses or replacing a query path with a more efficient one. After the rewriting process, the original query may change significantly. The rewrite_time field contains the cumulative total rewrite time for the query and all its children, in nanoseconds.
profile.shards.searches.collector Array of objects Profiling information about the Lucene collectors that ran the search.
profile.shards.aggregations Array of objects Profiling information about the aggregation execution.

The query object

The query object contains the following fields.

Field Data type Description
type String The Lucene query type into which the search query was rewritten. Corresponds to the Lucene class name (which often has the same name in OpenSearch).
description String Contains a Lucene explanation of the query. Helps differentiate queries with the same type.
time_in_nanos Long The amount of time the query took to execute, in nanoseconds. In a parent query, the time is inclusive of the execution times of all the child queries.
breakdown Object Contains timing statistics about low-level Lucene execution.
children Array of objects If a query has subqueries (children), this field contains information about the subqueries.

The breakdown object

The breakdown object represents the timing statistics about low-level Lucene execution, broken down by method. Timings are listed in wall-clock nanoseconds and are not normalized. The breakdown timings are inclusive of all child times. The breakdown object comprises the following fields. All fields contain integer values.

Field Description
create_weight A Query object in Lucene is immutable. Yet, Lucene should be able to reuse Query objects in multiple IndexSearcher objects. Thus, Query objects need to keep temporary state and statistics associated with the index in which the query is executed. To achieve reuse, every Query object generates a Weight object, which keeps the temporary context (state) associated with the <IndexSearcher, Query> tuple. The create_weight field contains the amount of time spent creating the Weight object.
build_scorer A Scorer iterates over matching documents and generates a score for each document. The build_scorer field contains the amount of time spent generating the Scorer object. This does not include the time spent scoring the documents. The Scorer initialization time depends on the optimization and complexity of a particular query. The build_scorer parameter also includes the amount of time associated with caching, if caching is applicable and enabled for the query.
next_doc The next_doc Lucene method returns the document ID of the next document that matches the query. This method is a special type of the advance method and is equivalent to advance(docId() + 1). The next_doc method is more convenient for many Lucene queries. The next_doc field contains the amount of time required to determine the next matching document, which varies depending on the query type.
advance The advance method is a lower-level version of the next_doc method in Lucene. It also finds the next matching document but necessitates that the calling query perform additional tasks, such as identifying skips. Some queries, such as conjunctions (must clauses in Boolean queries), cannot use next_doc. For those queries, advance is timed.
match For some queries, document matching is performed in two steps. First, the document is matched approximately. Second, those documents that are approximately matched are examined through a more comprehensive process. For example, a phrase query first checks whether a document contains all terms in the phrase. Next, it verifies that the terms are in order (which is a more expensive process). The match field is non-zero only for those queries that use the two-step verification process.
score Contains the time taken for a Scorer to score a particular document.
shallow_advance Contains the amount of time required to execute the advanceShallow Lucene method.
compute_max_score Contains the amount of time required to execute the getMaxScore Lucene method.
set_min_competitive_score Contains the amount of time required to execute the setMinCompetitiveScore Lucene method.
<method>_count Contains the number of invocations of a <method>. For example, advance_count contains the number of invocations of the advance method. Different invocations of the same method occur because the method is called on different documents. You can determine the selectivity of a query by comparing counts in different query components.

The collector array

The collector array contains information about Lucene Collectors. A Collector is responsible for coordinating document traversal and scoring and collecting matching documents. Using Collectors, individual queries can record aggregation results and execute global queries or post-query filters.

Field Description
name The collector name. In the example response, the collector is a single SimpleTopScoreDocCollector---the default scoring and sorting collector.
reason Contains a description of the collector. For possible field values, see Collector reasons.
time_in_nanos A wall-clock time, including timing for all children.
children If a collector has subcollectors (children), this field contains information about the subcollectors.

Collector times are calculated, combined, and normalized independently, so they are independent of query times. {: .note}

Collector reasons

The following table describes all available collector reasons.

Reason Description
search_sorted A collector that scores and sorts documents. Present in most simple searches.
search_count A collector that counts the number of matching documents but does not fetch the source. Present when size: 0 is specified.
search_terminate_after_count A collector that searches for matching documents and terminates the search when it finds a specified number of documents. Present when the terminate_after_count query parameter is specified.
search_min_score A collector that returns matching documents that have a score greater than a minimum score. Present when the min_score parameter is specified.
search_multi A wrapper collector for other collectors. Present when search, aggregations, global aggregations, and post filters are combined in a single search.
search_timeout A collector that stops running after a specified period of time. Present when a timeout parameter is specified.
aggregation A collector for aggregations that is run against the specified query scope. OpenSearch uses a single aggregation collector to collect documents for all aggregations.
global_aggregation A collector that is run against the global query scope. Global scope is different from a specified query scope, so in order to collect the entire dataset, a match_all query must be run.

Aggregations

To profile aggregations, send an aggregation request and provide the profile parameter set to true.

Example request: Global aggregation

GET /opensearch_dashboards_sample_data_ecommerce/_search
{
  "profile": "true",
  "size": 0,
  "query": {
    "match": { "manufacturer": "Elitelligence" }
  },
  "aggs": {
    "all_products": {
      "global": {}, 
      "aggs": {     
      "avg_price": { "avg": { "field": "taxful_total_price" } }
      }
    },
    "elitelligence_products": { "avg": { "field": "taxful_total_price" } }
  }
}

{% include copy-curl.html %}

Example response: Global aggregation

The response contains profiling information:

Response {: .text-delta}
{
  "took": 10,
  "timed_out": false,
  "_shards": {
    "total": 1,
    "successful": 1,
    "skipped": 0,
    "failed": 0
  },
  "hits": {
    "total": {
      "value": 1370,
      "relation": "eq"
    },
    "max_score": null,
    "hits": []
  },
  "aggregations": {
    "all_products": {
      "doc_count": 4675,
      "avg_price": {
        "value": 75.05542864304813
      }
    },
    "elitelligence_products": {
      "value": 68.4430200729927
    }
  },
  "profile": {
    "shards": [
      {
        "id": "[LidyZ1HVS-u93-73Z49dQg][opensearch_dashboards_sample_data_ecommerce][0]",
        "inbound_network_time_in_millis": 0,
        "outbound_network_time_in_millis": 0,
        "searches": [
          {
            "query": [
              {
                "type": "ConstantScoreQuery",
                "description": "ConstantScore(manufacturer:elitelligence)",
                "time_in_nanos": 1367487,
                "breakdown": {
                  "set_min_competitive_score_count": 0,
                  "match_count": 0,
                  "shallow_advance_count": 0,
                  "set_min_competitive_score": 0,
                  "next_doc": 634321,
                  "match": 0,
                  "next_doc_count": 1370,
                  "score_count": 0,
                  "compute_max_score_count": 0,
                  "compute_max_score": 0,
                  "advance": 173250,
                  "advance_count": 2,
                  "score": 0,
                  "build_scorer_count": 4,
                  "create_weight": 132458,
                  "shallow_advance": 0,
                  "create_weight_count": 1,
                  "build_scorer": 427458
                },
                "children": [
                  {
                    "type": "TermQuery",
                    "description": "manufacturer:elitelligence",
                    "time_in_nanos": 1174794,
                    "breakdown": {
                      "set_min_competitive_score_count": 0,
                      "match_count": 0,
                      "shallow_advance_count": 0,
                      "set_min_competitive_score": 0,
                      "next_doc": 470918,
                      "match": 0,
                      "next_doc_count": 1370,
                      "score_count": 0,
                      "compute_max_score_count": 0,
                      "compute_max_score": 0,
                      "advance": 172084,
                      "advance_count": 2,
                      "score": 0,
                      "build_scorer_count": 4,
                      "create_weight": 114041,
                      "shallow_advance": 0,
                      "create_weight_count": 1,
                      "build_scorer": 417751
                    }
                  }
                ]
              }
            ],
            "rewrite_time": 42542,
            "collector": [
              {
                "name": "MultiCollector",
                "reason": "search_multi",
                "time_in_nanos": 778406,
                "children": [
                  {
                    "name": "EarlyTerminatingCollector",
                    "reason": "search_count",
                    "time_in_nanos": 70290
                  },
                  {
                    "name": "ProfilingAggregator: [elitelligence_products]",
                    "reason": "aggregation",
                    "time_in_nanos": 502780
                  }
                ]
              }
            ]
          },
          {
            "query": [
              {
                "type": "ConstantScoreQuery",
                "description": "ConstantScore(*:*)",
                "time_in_nanos": 995345,
                "breakdown": {
                  "set_min_competitive_score_count": 0,
                  "match_count": 0,
                  "shallow_advance_count": 0,
                  "set_min_competitive_score": 0,
                  "next_doc": 930803,
                  "match": 0,
                  "next_doc_count": 4675,
                  "score_count": 0,
                  "compute_max_score_count": 0,
                  "compute_max_score": 0,
                  "advance": 2209,
                  "advance_count": 2,
                  "score": 0,
                  "build_scorer_count": 4,
                  "create_weight": 23875,
                  "shallow_advance": 0,
                  "create_weight_count": 1,
                  "build_scorer": 38458
                },
                "children": [
                  {
                    "type": "MatchAllDocsQuery",
                    "description": "*:*",
                    "time_in_nanos": 431375,
                    "breakdown": {
                      "set_min_competitive_score_count": 0,
                      "match_count": 0,
                      "shallow_advance_count": 0,
                      "set_min_competitive_score": 0,
                      "next_doc": 389875,
                      "match": 0,
                      "next_doc_count": 4675,
                      "score_count": 0,
                      "compute_max_score_count": 0,
                      "compute_max_score": 0,
                      "advance": 1167,
                      "advance_count": 2,
                      "score": 0,
                      "build_scorer_count": 4,
                      "create_weight": 9458,
                      "shallow_advance": 0,
                      "create_weight_count": 1,
                      "build_scorer": 30875
                    }
                  }
                ]
              }
            ],
            "rewrite_time": 8792,
            "collector": [
              {
                "name": "ProfilingAggregator: [all_products]",
                "reason": "aggregation_global",
                "time_in_nanos": 1310536
              }
            ]
          }
        ],
        "aggregations": [
          {
            "type": "AvgAggregator",
            "description": "elitelligence_products",
            "time_in_nanos": 319918,
            "breakdown": {
              "reduce": 0,
              "post_collection_count": 1,
              "build_leaf_collector": 130709,
              "build_aggregation": 2709,
              "build_aggregation_count": 1,
              "build_leaf_collector_count": 2,
              "post_collection": 584,
              "initialize": 4750,
              "initialize_count": 1,
              "reduce_count": 0,
              "collect": 181166,
              "collect_count": 1370
            }
          },
          {
            "type": "GlobalAggregator",
            "description": "all_products",
            "time_in_nanos": 1519340,
            "breakdown": {
              "reduce": 0,
              "post_collection_count": 1,
              "build_leaf_collector": 134625,
              "build_aggregation": 59291,
              "build_aggregation_count": 1,
              "build_leaf_collector_count": 2,
              "post_collection": 5041,
              "initialize": 24500,
              "initialize_count": 1,
              "reduce_count": 0,
              "collect": 1295883,
              "collect_count": 4675
            },
            "children": [
              {
                "type": "AvgAggregator",
                "description": "avg_price",
                "time_in_nanos": 775967,
                "breakdown": {
                  "reduce": 0,
                  "post_collection_count": 1,
                  "build_leaf_collector": 98999,
                  "build_aggregation": 33083,
                  "build_aggregation_count": 1,
                  "build_leaf_collector_count": 2,
                  "post_collection": 2209,
                  "initialize": 1708,
                  "initialize_count": 1,
                  "reduce_count": 0,
                  "collect": 639968,
                  "collect_count": 4675
                }
              }
            ]
          }
        ]
      }
    ]
  }
}

Example request: Non-global aggregation

GET /opensearch_dashboards_sample_data_ecommerce/_search
{
  "size": 0,
  "aggs": {
    "avg_taxful_total_price": {
      "avg": {
        "field": "taxful_total_price"
      }
    }
  }
}

{% include copy-curl.html %}

Example response: Non-global aggregation

The response contains profiling information:

Response {: .text-delta}
{
  "took": 13,
  "timed_out": false,
  "_shards": {
    "total": 1,
    "successful": 1,
    "skipped": 0,
    "failed": 0
  },
  "hits": {
    "total": {
      "value": 4675,
      "relation": "eq"
    },
    "max_score": null,
    "hits": []
  },
  "aggregations": {
    "avg_taxful_total_price": {
      "value": 75.05542864304813
    }
  },
  "profile": {
    "shards": [
      {
        "id": "[LidyZ1HVS-u93-73Z49dQg][opensearch_dashboards_sample_data_ecommerce][0]",
        "inbound_network_time_in_millis": 0,
        "outbound_network_time_in_millis": 0,
        "searches": [
          {
            "query": [
              {
                "type": "ConstantScoreQuery",
                "description": "ConstantScore(*:*)",
                "time_in_nanos": 1690820,
                "breakdown": {
                  "set_min_competitive_score_count": 0,
                  "match_count": 0,
                  "shallow_advance_count": 0,
                  "set_min_competitive_score": 0,
                  "next_doc": 1614112,
                  "match": 0,
                  "next_doc_count": 4675,
                  "score_count": 0,
                  "compute_max_score_count": 0,
                  "compute_max_score": 0,
                  "advance": 2708,
                  "advance_count": 2,
                  "score": 0,
                  "build_scorer_count": 4,
                  "create_weight": 20250,
                  "shallow_advance": 0,
                  "create_weight_count": 1,
                  "build_scorer": 53750
                },
                "children": [
                  {
                    "type": "MatchAllDocsQuery",
                    "description": "*:*",
                    "time_in_nanos": 770902,
                    "breakdown": {
                      "set_min_competitive_score_count": 0,
                      "match_count": 0,
                      "shallow_advance_count": 0,
                      "set_min_competitive_score": 0,
                      "next_doc": 721943,
                      "match": 0,
                      "next_doc_count": 4675,
                      "score_count": 0,
                      "compute_max_score_count": 0,
                      "compute_max_score": 0,
                      "advance": 1042,
                      "advance_count": 2,
                      "score": 0,
                      "build_scorer_count": 4,
                      "create_weight": 5041,
                      "shallow_advance": 0,
                      "create_weight_count": 1,
                      "build_scorer": 42876
                    }
                  }
                ]
              }
            ],
            "rewrite_time": 22000,
            "collector": [
              {
                "name": "MultiCollector",
                "reason": "search_multi",
                "time_in_nanos": 3672676,
                "children": [
                  {
                    "name": "EarlyTerminatingCollector",
                    "reason": "search_count",
                    "time_in_nanos": 78626
                  },
                  {
                    "name": "ProfilingAggregator: [avg_taxful_total_price]",
                    "reason": "aggregation",
                    "time_in_nanos": 2834566
                  }
                ]
              }
            ]
          }
        ],
        "aggregations": [
          {
            "type": "AvgAggregator",
            "description": "avg_taxful_total_price",
            "time_in_nanos": 1973702,
            "breakdown": {
              "reduce": 0,
              "post_collection_count": 1,
              "build_leaf_collector": 199292,
              "build_aggregation": 13584,
              "build_aggregation_count": 1,
              "build_leaf_collector_count": 2,
              "post_collection": 6125,
              "initialize": 6916,
              "initialize_count": 1,
              "reduce_count": 0,
              "collect": 1747785,
              "collect_count": 4675
            }
          }
        ]
      }
    ]
  }
}

Response fields

The aggregations array contains aggregation objects with the following fields.

Field Data type Description
type String The aggregator type. In the non-global aggregation example response, the aggregator type is AvgAggregator. Global aggregation example response contains a GlobalAggregator with an AvgAggregator child.
description String Contains a Lucene explanation of the aggregation. Helps differentiate aggregations with the same type.
time_in_nanos Long The amount of time taken to execute the aggregation, in nanoseconds. In a parent aggregation, the time is inclusive of the execution times of all the child aggregations.
breakdown Object Contains timing statistics about low-level Lucene execution.
children Array of objects If an aggregation has subaggregations (children), this field contains information about the subaggregations.
debug Object Some aggregations return a debug object that describes the details of the underlying execution.

The breakdown object

The breakdown object represents the timing statistics about low-level Lucene execution, broken down by method. Each field in the breakdown object represents an internal Lucene method executed within the aggregation. Timings are listed in wall-clock nanoseconds and are not normalized. The breakdown timings are inclusive of all child times. The breakdown object is comprised of the following fields. All fields contain integer values.

Field Description
initialize Contains the amount of time taken to execute the preCollection() callback method during AggregationCollectorManager creation.
build_leaf_collector Contains the time spent running the getLeafCollector() method of the aggregation, which creates a new collector to collect the given context.
collect Contains the time spent collecting the documents into buckets.
post_collection Contains the time spent running the aggregations postCollection() callback method.
build_aggregation Contains the time spent running the aggregations buildAggregations() method, which builds the results of this aggregation.
reduce Contains the time spent in the reduce phase.
<method>_count Contains the number of invocations of a <method>. For example, build_leaf_collector_count contains the number of invocations of the build_leaf_collector method.