Elasticsearch使用：Scripting API（一）

2021-02-04 16:34:09 浏览数 (1)

简介

官方7.9版本：https://www.elastic.co/guide/en/elasticsearch/reference/7.9/modules-scripting.html

通过ES脚本来解决，其允许用户在一些特定的API中对自定义表达式进行求值。

1. ES Scripting历史

版本

使用脚本

< Elasticsearch 1.4

MVEL 脚本

< Elasticsearch 5.0

Groovy 脚本

‘>= Elasticsearch 5.0

painless 脚本

2. Painless Scripting 简介

Painless是一种简单，安全的脚本语言，专为与Elasticsearch一起使用而设计。它是Elasticsearch的默认脚本语言，可以安全地用于内联和存储脚本。

Painless特点：

  • 性能优秀：Painless脚本运行速度比备选方案（包括Groovy）快几倍。
  • 安全性强：使用白名单来限制函数与字段的访问，避免了可能的安全隐患。
  • 可选输入：变量和参数可以使用显式类型或动态def类型。
  • 上手容易：扩展了java的基本语法，并兼容groove风格的脚本语言特性。
  • 特定优化：是ES官方专为Elasticsearch脚本编写而设计。

3. Scripting 应用场景

增删改查能解决业务场景80%的问题，Painless脚本操作一般应用于相对复杂的业务场景中。

  • 自定义字段
  • 自定义评分
  • 自定义更新
  • 自定义reindex
  • 聚合
  • 其他自定义操作

4. Scripting 使用模板

代码语言：javascript复制
"script": {
    "lang":   "...",  # 代表language脚本语言，默认指定为：painless
    "source" | "id": "...",  # 脚本的核心部分，id应用于：stored script
    "params": { ... }  # 传递给脚本使用的变量参数
  }

Scripting应用

1. 自定义字段

如：需要给每个doc的complexrank字段翻倍并返回翻倍后的值

代码语言：javascript复制
POST sphinx-doctor/_search
{
  "from": 0,
  "size": 20,
  "query": {
    "match_all": {}
  },
  "_source": "complexrank",
  "script_fields": {
    "custom_field": {
      "script": {
        "lang": "expression", # 这里脚本语言选择的expression
        "source": "doc['complexrank'] * multiplier",
        "params": {
          "multiplier": 2
        }
      }
    }
  }
}
说明：对原索引中的complexrank字段值进行2倍返回给custom_field字段

{
    "took":20,
    "timed_out":false,
    "_shards":{
        "total":1,
        "successful":1,
        "skipped":0,
        "failed":0
    },
    "hits":{
        "total":194354,
        "max_score":1,
        "hits":[
            {
                "_index":"sphinx-doctor-20.11.06-103145",
                "_type":"_doc",
                "_id":"740",
                "_score":1,
                "_source":{
                    "complexrank":"5985"
                },
                "fields":{
                    "custom_field":[
                        11970
                    ]
                }
            },
            {
                "_index":"sphinx-doctor-20.11.06-103145",
                "_type":"_doc",
                "_id":"742",
                "_score":1,
                "_source":{
                    "complexrank":"5325"
                },
                "fields":{
                    "custom_field":[
                        10650
                    ]
                }
            }
        ]
    }
}

如：返回日期字段中的“年”或“月”或“日”等

代码语言：javascript复制
POST drug/_search
{
  "from": 0,
  "size": 20,
  "query": {
    "match_all": {}
  },
  "script_fields": {
    "custom_field": {
      "script": {
        "source": "doc.ctime.value.year" #月：month
      }
    }
  }
}

{
    "took":57,
    "timed_out":false,
    "_shards":{
        "total":1,
        "successful":1,
        "skipped":0,
        "failed":0
    },
    "hits":{
        "total":173536,
        "max_score":1,
        "hits":[
            {
                "_index":"drug-20.12.03-151452",
                "_type":"_doc",
                "_id":"1883795984",
                "_score":1,
                "fields":{
                    "custom_field":[
                        2014
                    ]
                }
            },
            {
                "_index":"drug-20.12.03-151452",
                "_type":"_doc",
                "_id":"1883795985",
                "_score":1,
                "fields":{
                    "custom_field":[
                        2014
                    ]
                }
            }
        ]
    }
}

2. 自定义评分

代码语言：javascript复制
POST sphinx-doctor/_search
{
  "from": 0,
  "size": 2,
  "_source": "hospitalname", 
  "query": {
    "function_score": {
      "query": {
        "match": {
          "hospitalname": {
            "query": "北京协和医院"
          }
        }
      },
      "functions": [
        {
          "filter": {
            "match_all": {
              "boost": 1
            }
          },
          "script_score": {
            "script": {
              "source": "_score *params._score   doc['rank'].value * params.rank   doc['adminlevel'].value * params.adminlevel",
              "lang": "painless",  # # 是Lucene’s expressions 脚本语言
              "params": {
                "adminlevel": 2500,
                "rank": 0.5,
                "_score": 1
              }
            }
          }
        }
      ],
      "score_mode": "sum",
      "max_boost": 3.4028235e 38,
      "boost": 1
    }
  },
  "track_scores": true
}

{
  "took" : 487,
  "timed_out" : false,
  "_shards" : {
    "total" : 1,
    "successful" : 1,
    "skipped" : 0,
    "failed" : 0
  },
  "hits" : {
    "total" : 777965,
    "max_score" : 449721.3,
    "hits" : [
      {
        "_index" : "sphinx-doctor-20.12.09-010000",
        "_type" : "_doc",
        "_id" : "175477",
        "_score" : 449721.3,
        "_source" : {
          "hospitalname" : "北京协和医院"
        }
      },
      {
        "_index" : "sphinx-doctor-20.12.09-010000",
        "_type" : "_doc",
        "_id" : "221609",
        "_score" : 440269.34,
        "_source" : {
          "hospitalname" : "北京协和医院"
        }
      }
    ]
  }
}

Java API:排序

String scriptText = "_score *params._score   doc['rank'].value * params.rank   doc['adminlevel'].value * params.adminlevel";

Map<String, Object> params = new HashMap<>();
params.put("_score", 1.0f);
params.put("rank", 0.5f);
params.put("adminlevel", 2500f);

Script script = new Script(ScriptType.INLINE, "painless", scriptText, params);

ScriptScoreFunctionBuilder scriptScoreFunctionBuilder = ScoreFunctionBuilders.scriptFunction(script);
FunctionScoreQueryBuilder functionScoreQueryBuilder = QueryBuilders.functionScoreQuery(boolQueryBuilder, scriptScoreFunctionBuilder)
                        .scoreMode(FunctionScoreQuery.ScoreMode.SUM);

builder.query(functionScoreQueryBuilder);
builder.from(offset);
builder.size(limit);
//当使用排序_sort 来指定依据某些字段排序。就不会计算得分，需要设置"track_scores":true,这样分数就会被计算和跟踪。
builder.trackScores(true);

3. 自定义更新

update

将已有字段值赋值给其他字段。

代码语言：javascript复制
POST sphinx-doctor/_doc/102647/_update
{
  "script": {
    "lang": "painless",
    "source": "ctx._source.hospitalname = params.hospitalname;ctx._source.name = params.name",
    "params": {
      "hospitalname": "北京协和医院",
      "name": "协和医生"
    }
  }
}

update_by_query

代码语言：javascript复制
POST sphinx-doctor/_update_by_query
{
  "query": {
    "term": {
      "id": {
        "value": "102647"
      }
    }
  },
  "script": {
    "lang": "painless",
    "source": """
       if (ctx._source.registerordercount >= 500) {
          ctx._source.registerordercount  = 200;
       } else {
          ctx.op = 1000;
      }
   """
  }
}

对row<=3且sold为false的，将cost字段值减2
POST /seats/_update_by_query
{
    "query": {
        "bool": {
            "filter": [
            {
                "range": {
                    "row": {
                        "lte": 3
                    }
                }
            },
            {
                "match": {
                    "sold": false
                }
            }]
        }
    },
    "script": {
        "source": "ctx._source.cost -= params.discount",
        "lang": "painless",
        "params": {
            "discount": 2
        }
    }
}

ingest pipeline

在ingest pipeline中使用script processor：如果字段locales值为空，则其设置成"en-en"

代码语言：javascript复制
PUT _ingest/pipeline/fix_locales
{
  "processors": [
    {
      "script": {
        "source": """
  if (ctx.locales == "") {
    ctx.locales = "en-en";
  }
"""
      }
    }
  ]
}

值得注意的是，在 ingest processor上下文 中，通过ctx变量访问文档字段是不需要加_source的。

4.自定义reindex

代码语言：javascript复制
POST _reindex
{
  "source": {
    "index": "sphinx-doctor-20.12.02-150616",
    "size": 4000
  },
  "dest": {
    "index": "sphinx-doctor-20.12.03-151452"
  },
  "script": {
    "source": "ctx._source.complexrank  = 10;nctx._source.netcaseprice = 100;"
  }
}

5. 聚合

代码语言：javascript复制
POST sphinx-doctor/_search
{
  "from": 0,
  "size": 20, 
  "query": {
    "match": {
      "hospitalname": "北京协和医院"
    }
  },
  "aggs": {
    "grade": {
      "terms": {
        "script": {
          "source": "doc['grade.keyword'].value",
          "lang": "painless"
        }
      }
    }
  }
}

{
  "took" : 187,
  "timed_out" : false,
  "_shards" : {
    "total" : 1,
    "successful" : 1,
    "skipped" : 0,
    "failed" : 0
  },
  "hits" : {
    "total" : 193445,
    "max_score" : 44.18691,
    "hits" : [
      {
        "_index" : "sphinx-doctor-20.11.06-103145",
        "_type" : "_doc",
        "_id" : "30626487346",
        "_score" : 44.18691,
        "_source" : {
          "registerordercount" : 0,
          "hospitalfacultyname" : "神经内科",
          "idx_doctoridprimary" : "DoctorIdPrimary_335",
          "hospitaldistrict" : "东城",
          "caseopened" : true,
          "isonline" : null,
          "dummy" : "SELECT_ALL",
          "facultyid" : "1007000",
          "price" : "10",
          "rank" : "0",
          "ctime" : "1568269475",
          "id" : "30626487346",
          "clinicprice" : "20.00",
          "idx_hospitalfacultyid" : "HospitalFacultyId_335",
          "educategrade" : "",
          "adminlevel" : "1",
          "isprimarydoctor" : 1,
          "isexpert" : true,
          "bookingvisitnum" : 0,
          "primaryid" : "30626487346",
          "hospitalfacultyid" : "335",
          "spaceid" : "200007660088",
          "hospitalcity" : "北京",
          "isopenvideo" : true,
          "grade" : "主任医师",
          "name" : "3 0626487346",
          "idx_fix_bigcity" : "北京协和医院北京协和医院北京协和医院北京协和医院测试用",
          "phoneopened" : true,
          "onlineschedule" : "20201207,20201214,20201221",
          "isvideotpl" : false,
          "issanjia" : true,
          "hospitalprovince" : "北京",
          "servicelevel" : 2,
          "title" : "",
          "confirmed" : "1",
          "isvip" : false,
          "general" : 0,
          "menzhenprice" : "10",
          "isopencosvideo" : false,
          "hospitalname" : "北京协和医院北京协和医院北京协和医院北京协和医院测试用",
          "netcaseprice" : "20.00",
          "registrprice" : 0,
          "free" : 0,
          "workstatus" : "0",
          "registtationopened" : null,
          "indextype" : "doctor",
          "utime" : 1606978403,
          "complexrank" : "5985",
          "sex" : "1",
          "reservationopened" : null,
          "idx_doctorid" : "DoctorId_30626487346",
          "idx_hospital_info" : "北京协和医院北京协和医院北京协和医院北京协和医院测试用,北京协和医院,33北京协和医院,协和医院,协和东院,协和东院区,北京协和医院东院,协和西院,北京邮电总医院,邮电总医院,北京协和西院,北京协和医院西院区,北京协和医院西院,北京协和,北京市协和,北京邮电医院,协合医院,北京市协和医院,中国医学科学院北京协和医院,北京协合医院45,协和医院,北京协和,北京市协和,协和东院,北京协和医院东院,协和西院,北京邮电医院,北京协和西院,北京协和医院西院,协合医院,北京市协和医院,中国医学科学院北京协和医院,北京协合医院",
          "isopenrecipe" : false,
          "hits" : "0",
          "iscosmetologydoctor" : null,
          "hospitalid" : "1",
          "idx_facultyid" : "FacultyId_1007000",
          "activitytime" : "1568269520",
          "hospitalgrade" : "6",
          "idx_hospitalid" : "HospitalId_1",
          "username" : "francoliu"
        }
      },
      {
        "_index" : "sphinx-doctor-20.11.06-103145",
        "_type" : "_doc",
        "_id" : "310346050824",
        "_score" : 40.138744,
        "_source" : {
          "registerordercount" : 0,
          "hospitalfacultyname" : "心血管内科",
          "idx_doctoridprimary" : "DoctorIdPrimary_341",
          "hospitaldistrict" : "东城",
          "caseopened" : false,
          "isonline" : null,
          "dummy" : "SELECT_ALL",
          "facultyid" : "1010000",
          "price" : 0,
          "rank" : "0",
          "ctime" : "1605859848",
          "id" : "310346050824",
          "clinicprice" : 0,
          "idx_hospitalfacultyid" : "HospitalFacultyId_341",
          "educategrade" : "教授",
          "adminlevel" : "4",
          "isprimarydoctor" : 1,
          "isexpert" : true,
          "bookingvisitnum" : 0,
          "primaryid" : "310346050824",
          "hospitalfacultyid" : "341",
          "spaceid" : "0",
          "hospitalcity" : "北京",
          "isopenvideo" : null,
          "grade" : "主任医师",
          "name" : "地名",
          "idx_fix_bigcity" : "北京协和医院",
          "phoneopened" : false,
          "onlineschedule" : "",
          "isvideotpl" : false,
          "issanjia" : true,
          "hospitalprovince" : "北京",
          "servicelevel" : 0,
          "title" : "",
          "confirmed" : "",
          "isvip" : false,
          "general" : 0,
          "menzhenprice" : 0,
          "isopencosvideo" : false,
          "hospitalname" : "北京协和医院",
          "netcaseprice" : 0,
          "registrprice" : 0,
          "free" : 0,
          "workstatus" : "0",
          "registtationopened" : null,
          "indextype" : "doctor",
          "utime" : 1605859882,
          "complexrank" : "0",
          "sex" : "1",
          "reservationopened" : null,
          "idx_doctorid" : "DoctorId_310346050824",
          "idx_hospital_info" : "北京协和医院,北京协和医院,33北京协和医院,协和医院,协和东院,协和东院区,北京协和医院东院,协和西院,北京邮电总医院,邮电总医院,北京协和西院,北京协和医院西院区,北京协和医院西院,北京协和,北京市协和,北京邮电医院,协合医院,北京市协和医院,中国医学科学院北京协和医院,北京协合医院45,协和医院,北京协和,北京市协和,协和东院,北京协和医院东院,协和西院,北京邮电医院,北京协和西院,北京协和医院西院,协合医院,北京市协和医院,中国医学科学院北京协和医院,北京协合医院",
          "isopenrecipe" : null,
          "hits" : "0",
          "iscosmetologydoctor" : null,
          "hospitalid" : "1",
          "idx_facultyid" : "FacultyId_1010000",
          "activitytime" : null,
          "hospitalgrade" : "6",
          "idx_hospitalid" : "HospitalId_1",
          "username" : ""
        }
      }
    ]
  },
  "aggregations" : {
    "grade" : {
      "doc_count_error_upper_bound" : 0,
      "sum_other_doc_count" : 479,
      "buckets" : [
        {
          "key" : "主任医师",
          "doc_count" : 77699
        },
        {
          "key" : "副主任医师",
          "doc_count" : 72939
        },
        {
          "key" : "主治医师",
          "doc_count" : 20399
        },
        {
          "key" : "",
          "doc_count" : 13558
        },
        {
          "key" : "住院医师",
          "doc_count" : 5731
        },
        {
          "key" : "副主任技师",
          "doc_count" : 896
        },
        {
          "key" : "副主任药师",
          "doc_count" : 612
        },
        {
          "key" : "主管技师",
          "doc_count" : 468
        },
        {
          "key" : "主任药师",
          "doc_count" : 355
        },
        {
          "key" : "副主任检验师",
          "doc_count" : 309
        }
      ]
    }
  }
}

6.自定义排序

两个或多个字段进行运算返回一个值进行排序

代码语言：javascript复制
POST sphinx-doctor/_search
{
  "_source": [
    "clinicprice",
    "menzhenprice"
  ],
  "query": {
    "match_all": {}
  },
  "sort": {
    "_script": {
      "type": "number",  # string
      "order": "desc",
      "script": {
        "lang": "painless",
        "source": "doc['clinicprice'].value   doc['menzhenprice'].value"
      }
    }
  }
}

{
  "took" : 334,
  "timed_out" : false,
  "_shards" : {
    "total" : 1,
    "successful" : 1,
    "skipped" : 0,
    "failed" : 0
  },
  "hits" : {
    "total" : 782852,
    "max_score" : null,
    "hits" : [
      {
        "_index" : "sphinx-doctor-20.12.09-010000",
        "_type" : "_doc",
        "_id" : "102647",
        "_score" : null,
        "_source" : {
          "menzhenprice" : "1400",
          "clinicprice" : "2700.00"
        },
        "sort" : [
          4100.0
        ]
      },
      {
        "_index" : "sphinx-doctor-20.12.09-010000",
        "_type" : "_doc",
        "_id" : "8231",
        "_score" : null,
        "_source" : {
          "menzhenprice" : "2000.00",
          "clinicprice" : "2000.00"
        },
        "sort" : [
          4000.0
        ]
      }
    ]
  }
}

l

逻辑运算符进行判断来影响排序

代码语言：javascript复制
POST sphinx-doctor/_search
{
  "_source": [
    "clinicprice",
    "menzhenprice"
  ],
  "from": 0,
  "size": 2, 
  "query": {
    "match_all": {}
  },
   "sort": [
    {
      "complexrank": {
        "order": "desc"
      }
    },
    {
      "_script": {
        "script": {
          "inline": "'北京 '==doc['hospitalprovince.keyword'].value?0:('陕西'==doc['hospitalprovince.keyword'].value?1:2)"
        },
        "type": "number",
        "order": "asc"
      }
    }
  ]
}

{
  "took" : 80,
  "timed_out" : false,
  "_shards" : {
    "total" : 1,
    "successful" : 1,
    "skipped" : 0,
    "failed" : 0
  },
  "hits" : {
    "total" : 782852,
    "max_score" : null,
    "hits" : [
      {
        "_index" : "sphinx-doctor-20.12.09-010000",
        "_type" : "_doc",
        "_id" : "5279893112",
        "_score" : null,
        "_source" : {
          "menzhenprice" : "500",
          "clinicprice" : 0
        },
        "sort" : [
          981,
          2.0
        ]
      },
      {
        "_index" : "sphinx-doctor-20.12.09-010000",
        "_type" : "_doc",
        "_id" : "124096",
        "_score" : null,
        "_source" : {
          "menzhenprice" : "200.00",
          "clinicprice" : "200.00"
        },
        "sort" : [
          980,
          2.0
        ]
      }
    ]
  }
}

在 update, update-by-query, 或 reindex API中使用脚本时，需要通过ctx去访问文档中的字段。

  • ctx._source： 访问文档_source字段
  • ctx.op: 对文档对应的操作，包括index和delete
  • ctx._index : 访问文档的 meta-fields
  • 其他字段或变量的访问见： update context

7.删除一个字段

我们可以使用脚本删除字段/嵌套字段。 您要做的就是使用 remove 方法并传入字段/嵌套字段名称。 例如，假设我们要删除 ID 为5的文档的嵌套字段 “device”。

代码语言：javascript复制
POST tweets/_update/5
{
  "script": {
    "source": "ctx._source.info.remove(params.fieldname)",
    "params": {
      "fieldname": "device"
    }
  }
}
ElasticsearchService 全文检索

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