1.有序操作列表将会串行执行,但如果在一个写操作过程出现异常错误,则不会处理剩余的任何写操作

2.无序操作列表将会并发执行,如果在一个写操作过程出现异常错误,则不影响,继续执行(并发无序)

3.对比无序操作,有序操作在分片中普遍比较慢

4.使用 bulkWrite() 有序操作

5.bulkWrite支持的类型

insertOne
updateOne
updateMany
replaceOne
deleteOne
deleteMany

6.使用bulkWrite操作案例

try {
db.characters.bulkWrite(
[
{ insertOne :
{
"document" :
{
"_id" : 4, "char" : "Dithras", "class" : "barbarian", "lvl" : 4
}
}
},
{ insertOne :
{
"document" :
{
"_id" : 5, "char" : "Taeln", "class" : "fighter", "lvl" : 3
}
}
},
{ updateOne :
{
"filter" : { "char" : "Eldon" },
"update" : { $set : { "status" : "Critical Injury" } }
}
},
{ deleteOne :
{ "filter" : { "char" : "Brisbane"} }
},
{ replaceOne :
{
"filter" : { "char" : "Meldane" },
"replacement" : { "char" : "Tanys", "class" : "oracle", "lvl" : 4 }
}
}
]
);
}
catch (e) {
print(e);
}

Overview

MongoDB provides clients the ability to perform write operations in bulk. Bulk write operations affect a singlecollection. MongoDB allows applications to determine the acceptable level of acknowledgement required for bulk write operations.

New in version 3.2.

The db.collection.bulkWrite() method provides the ability to perform bulk insert, update, and remove operations. MongoDB also supports bulk insert through the db.collection.insertMany().

Ordered vs Unordered Operations

Bulk write operations can be either ordered or unordered.

With an ordered list of operations, MongoDB executes the operations serially. If an error occurs during the processing of one of the write operations, MongoDB will return without processing any remaining write operations in the list. See ordered Bulk Write

With an unordered list of operations, MongoDB can execute the operations in parallel, but this behavior is not guaranteed. If an error occurs during the processing of one of the write operations, MongoDB will continue to process remaining write operations in the list. See Unordered Bulk Write.

Executing an ordered list of operations on a sharded collection will generally be slower than executing an unordered list since with an ordered list, each operation must wait for the previous operation to finish.

By default, bulkWrite() performs ordered operations. To specify unordered write operations, setordered : false in the options document.

See Execution of Operations

bulkWrite() Methods

bulkWrite() supports the following write operations:

Each write operation is passed to bulkWrite() as a document in an array.

For example, the following performs multiple write operations:

The characters collection contains the following documents:

{ "_id" : 1, "char" : "Brisbane", "class" : "monk", "lvl" : 4 },
{ "_id" : 2, "char" : "Eldon", "class" : "alchemist", "lvl" : 3 },
{ "_id" : 3, "char" : "Meldane", "class" : "ranger", "lvl" : 3 }

The following bulkWrite() performs multiple operations on the collection:

try {
db.characters.bulkWrite(
[
{ insertOne :
{
"document" :
{
"_id" : 4, "char" : "Dithras", "class" : "barbarian", "lvl" : 4
}
}
},
{ insertOne :
{
"document" :
{
"_id" : 5, "char" : "Taeln", "class" : "fighter", "lvl" : 3
}
}
},
{ updateOne :
{
"filter" : { "char" : "Eldon" },
"update" : { $set : { "status" : "Critical Injury" } }
}
},
{ deleteOne :
{ "filter" : { "char" : "Brisbane"} }
},
{ replaceOne :
{
"filter" : { "char" : "Meldane" },
"replacement" : { "char" : "Tanys", "class" : "oracle", "lvl" : 4 }
}
}
]
);
}
catch (e) {
print(e);
}

The operation returns the following:

{
"acknowledged" : true,
"deletedCount" : 1,
"insertedCount" : 2,
"matchedCount" : 2,
"upsertedCount" : 0,
"insertedIds" : {
"0" : 4,
"1" : 5
},
"upsertedIds" : { }
}

For more examples, see bulkWrite() Examples

Strategies for Bulk Inserts to a Sharded Collection

Large bulk insert operations, including initial data inserts or routine data import, can affect sharded clusterperformance. For bulk inserts, consider the following strategies:

Pre-Split the Collection

If the sharded collection is empty, then the collection has only one initial chunk, which resides on a single shard. MongoDB must then take time to receive data, create splits, and distribute the split chunks to the available shards. To avoid this performance cost, you can pre-split the collection, as described in Split Chunks in a Sharded Cluster.

Unordered Writes to mongos

To improve write performance to sharded clusters, use bulkWrite() with the optional parameter orderedset to falsemongos can attempt to send the writes to multiple shards simultaneously. For emptycollections, first pre-split the collection as described in Split Chunks in a Sharded Cluster.

Avoid Monotonic Throttling

If your shard key increases monotonically during an insert, then all inserted data goes to the last chunk in the collection, which will always end up on a single shard. Therefore, the insert capacity of the cluster will never exceed the insert capacity of that single shard.

If your insert volume is larger than what a single shard can process, and if you cannot avoid a monotonically increasing shard key, then consider the following modifications to your application:

  • Reverse the binary bits of the shard key. This preserves the information and avoids correlating insertion order with increasing sequence of values.
  • Swap the first and last 16-bit words to “shuffle” the inserts.

EXAMPLE

The following example, in C++, swaps the leading and trailing 16-bit word of BSON ObjectIds generated so they are no longer monotonically increasing.

using namespace mongo;
OID make_an_id() {
OID x = OID::gen();
const unsigned char *p = x.getData();
swap( (unsigned short&) p[0], (unsigned short&) p[10] );
return x;
} void foo() {
// create an object
BSONObj o = BSON( "_id" << make_an_id() << "x" << 3 << "name" << "jane" );
// now we may insert o into a sharded collection
}

SEE ALSO

Shard Keys for information on choosing a sharded key. Also see Shard Key Internals (in particular,Choosing a Shard Key).

20.Bulk Write Operations-官方文档摘录的更多相关文章

  1. Cocos Creator 加载和切换场景(官方文档摘录)

    Cocos Creator 加载和切换场景(官方文档摘录) 在 Cocos Creator 中,我们使用场景文件名( 可以不包含扩展名)来索引指代场景.并通过以下接口进行加载和切换操作: cc.dir ...

  2. ng的概念层次(官方文档摘录)

    官方文档是这么说的: You write Angular applications by: composing HTML templates with Angularized markup, writ ...

  3. Cocos Creator 生命周期回调(官方文档摘录)

    Cocos Creator 为组件脚本提供了生命周期的回调函数.用户通过定义特定的函数回调在特定的时期编写相关 脚本.目前提供给用户的声明周期回调函数有: onLoad start update la ...

  4. Cocos Creator 使用计时器(官方文档摘录)

    在 Cocos Creator 中,我们为组件提供了方便的计时器,这个计时器源自于 Cocos2d-x 中的 cc.Scheduler,我们将它保留在了 Cocos Creator 中并适配了基于组件 ...

  5. angular 模板语法(官方文档摘录)

    https://angular.cn/guide/template-syntax {{}} 和"" 如果嵌套,{{}}里面求完值,""就是原意 <h3&g ...

  6. Qt元类型(MetaType)注册入门(附一些官方文档的关键摘录)

    昨天调试项目时,突然发现如下消息: QObject::connect: Cannot queue arguments of type 'ERROR_LEVEL' (Make sure 'ERROR_L ...

  7. hbase官方文档(转)

    FROM:http://www.just4e.com/hbase.html Apache HBase™ 参考指南  HBase 官方文档中文版 Copyright © 2012 Apache Soft ...

  8. HBase官方文档

    HBase官方文档 目录 序 1. 入门 1.1. 介绍 1.2. 快速开始 2. Apache HBase (TM)配置 2.1. 基础条件 2.2. HBase 运行模式: 独立和分布式 2.3. ...

  9. Spark SQL 官方文档-中文翻译

    Spark SQL 官方文档-中文翻译 Spark版本:Spark 1.5.2 转载请注明出处:http://www.cnblogs.com/BYRans/ 1 概述(Overview) 2 Data ...

  10. Spark Streaming官方文档学习--上

    官方文档地址:http://spark.apache.org/docs/latest/streaming-programming-guide.html Spark Streaming是spark ap ...

随机推荐

  1. Centos7+PHP5.6+MySQL5.7+Zabbix4.0部署

    Centos7+PHP5.6+MySQL5.7+Zabbix4.0部署 系统版本:CentOS Linux release 7.4.1708 (Core) 最小化安装 内核版本:3.10.0-693. ...

  2. typeof关键字

    C语言中 typeof 关键字是用来定义变量数据类型的.在linux内核源代码中广泛使用. 使用方法 1.当x的类型为是 int 时 _min1变量的数据类型则为 int. 2.当x为一个表达式时(例 ...

  3. DDR2基础

    一. DDR2介绍 DDR2由JEDEC(电子设备工程联合委员会)开发的新生代内存技术标准.该标准定义了DDR2封装.寻址及操作.电气等所有特性. DDR相关技术对比 DDR DDR2 DDR3 电压 ...

  4. sqlite3命令读出sqlite3格式的文件内容案例

    /*********************************************************************  * Author  : Samson  * Date   ...

  5. FastDFS 双tracker负载均衡 及多组存储配置

    应用场景: 三台服务器分别做三组存储,并且需要两台tracker地址做主备关系,当一台down机后需要另外一台可以提供正常的访问连接 #注:此处不考虑存储数据安全性,如果需要保障数据不丢失,可以分别每 ...

  6. Softmax回归推导过程

    http://www.cnblogs.com/Deep-Learning/p/7073744.html http://www.cnblogs.com/lutingting/p/4768882.html ...

  7. JavaScript处理JSON

    一.什么是JSON? JSON(JavaScript Object Notation) 是一种轻量级的数据交换格式.易于人阅读和编写.同时也易于机器解析和生成.它基于JavaScript(Standa ...

  8. Android的Parcelable中describeContents方法的作用

    这个方法返回的值通常为0,那什么情况下需要填写其他值呢? 这个方法到目前为止返回其他唯一有效的值就是CONTENTS_FILE_DESCRIPTOR(0x01),指明这个Parcel的内容包含文件描述 ...

  9. 数据库unsigned char*类型图片存进

    loadimage1();测试: void Caccess_test_1Dlg::loadimage1()//存入unsigned char*类型的数据图片 { CFileException e; I ...

  10. VC++ ListCtrl Report使用

    1.在VC++ 6.0中新建基于对话框的MFC应用程序ListCtrl; 2.在主对话框上添加一个List Control至合适的位置及大小: 3.在对话框OnInitDialog中初始化ListCt ...