Spring Data MongoDB 慢 MongoTemplate.find() 性能 [英] Spring Data MongoDB Slow MongoTemplate.find() Performance

问题描述

我在查询约 12,000 个用户文档时遇到性能问题，按 1 列(公司 ID)索引，没有其他过滤器.整个收藏只有~27000.我花了大约 12 秒来获取 ~12000 行数据...

I'm having performance issues when querying ~12,000 user documents, indexed by 1 column, (companyId), no other filter. The whole collection only has ~27000. It took me about 12 seconds to get the ~12000 rows of data...

我尝试为这个查询运行解释:db.instoreMember.find({companyId:"5b6be3e2096abd567974f924"}).explain();

I tried running explain for this query: db.instoreMember.find({companyId:"5b6be3e2096abd567974f924"}).explain();

结果如下:

{
    "queryPlanner" : {
        "plannerVersion" : 1,
        "namespace" : "production.instoreMember",
        "indexFilterSet" : false,
        "parsedQuery" : {
            "companyId" : {
                "$eq" : "5b6be3e2096abd567974f924"
            }
        },
        "winningPlan" : {
            "stage" : "FETCH",
            "inputStage" : {
                "stage" : "IXSCAN",
                "keyPattern" : {
                    "companyId" : 1,
                    "name" : 1,
                    "phoneNumber" : 1
                },
                "indexName" : "companyId_1_name_1_phoneNumber_1",
                "isMultiKey" : false,
                "multiKeyPaths" : {
                    "companyId" : [ ],
                    "name" : [ ],
                    "phoneNumber" : [ ]
                },
                "isUnique" : true,
                "isSparse" : false,
                "isPartial" : false,
                "indexVersion" : 2,
                "direction" : "forward",
                "indexBounds" : {
                    "companyId" : [
                        "[\"5b6be3e2096abd567974f924\", \"5b6be3e2096abd567974f924\"]"
                    ],
                    "name" : [
                        "[MinKey, MaxKey]"
                    ],
                    "phoneNumber" : [
                        "[MinKey, MaxKey]"
                    ]
                }
            }
        },
        "rejectedPlans" : [
            {
                "stage" : "FETCH",
                "inputStage" : {
                    "stage" : "IXSCAN",
                    "keyPattern" : {
                        "companyId" : 1
                    },
                    "indexName" : "companyId_1",
                    "isMultiKey" : false,
                    "multiKeyPaths" : {
                        "companyId" : [ ]
                    },
                    "isUnique" : false,
                    "isSparse" : false,
                    "isPartial" : false,
                    "indexVersion" : 2,
                    "direction" : "forward",
                    "indexBounds" : {
                        "companyId" : [
                            "[\"5b6be3e2096abd567974f924\", \"5b6be3e2096abd567974f924\"]"
                        ]
                    }
                }
            }
        ]
    },
    "serverInfo" : {

    },
    "ok" : 1
}

看来它实际上是在使用索引的companyId字段，如果我直接通过mongodb shell进行搜索，它的速度非常快:只有1~2秒.

It seems that it is actually using the indexed companyId field, and if i do the search directly via mongodb shell, it's very fast: only 1~2 seconds.

但是通过 Spring MongoDB 数据 - MongoTemplate:

But via Spring MongoDB Data - MongoTemplate:

final Query query = new Query().addCriteria(Criteria.where("companyId").is(adminCompanyId));
final List<InstoreMember> listOfInstoreMembers = mongoTemplate.find(query, InstoreMember.class);

这会变得非常慢~10-12 秒.(我的衡量方法是在 find 语句处放置一个断点，让它逐步执行到下一行，大约需要 10-12 秒)

This becomes very slow ~10-12seconds. (How i measure is that I put a break point at the find statement, let it step through to next line, which took about ~10-12seconds)

我为 mongodb spring bootstrap 添加了 DEBUG 行，这里是 find 语句的记录输出:

I've added the DEBUG line for mongodb spring bootstrap and here is the logged output of the find statement :

2018-08-14 23:53:34.493 DEBUG 22733 --- [bio-8080-exec-2] o.s.data.mongodb.core.MongoTemplate      : 
find using query: { "companyId" : "58fa36dd31d103038e64b061"} fields: null for class: class fn.model.InstoreMember in collection: instoreMember

我使用的 spring-data-mongodb 版本:

Version of spring-data-mongodb i use:

compile ("org.springframework.data:spring-data-mongodb:1.10.7.RELEASE")

推荐答案

我遇到了这个问题.

较慢的部分是将 Document 映射到 Java 对象.Mongo 模板不在编解码器级别映射，因此它转到 bson->Document->POJO.如果您只使用带有 POJO 编解码器的 mongo 驱动程序，它将转到 bson->pojo 并删除模板映射层开销.

The slow part is mapping Document to Java object. Mongo template doesn't map at the codec level so it goes bson->Document->POJO. If you use just the mongo driver with the POJO codec that will go bson->pojo and remove the template mapping layer overhead.

此外，如果您有旧数据并移动了包，这也会破坏它们的映射层并使其在回退到反射时超慢.

Also, if you have old data and have moved packages, this will also break their mapping layer and make it super slow as it falls back to reflection.

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