MongoDB Series (iii): MongoDB Shard

1. Shards of Monogdb (sharding)

Sharding is a data storage method used by MongoDB for terabytes of data above the TB level.

MongoDB uses a solution that splits the collection and then splits the data into several MongoDB instances.

In shard mode, MongoDB instances are divided into three types:

Shards: MongoDB that stores data

Config: Save the set Monogdb

Routing (MONGOs): MongoDB for Shard processing

2. Configuring the Shard 2.1 pilot environment

1 MONGOs, 1 config, 2 shard

Config:  test166:27019mongos:  test166:27020shards:  test166:27017,test167:27017

MongoDB is a single component and does not use a replica set

2.2 Start Config

Start config instance on test166, Port 27019

# Mongod--configsvr--dbpath/var/lib/mongo-c--port 27019

2.3 Start MONGOs

Launching the routing instance on test166, Port 27020

# MONGOs--configdb test166:27019--port 27020

2.4 Start shards

Start the shards on test166 and test167 respectively

#/etc/init.d/mongod Start

2.5 Adding shards

Connection Monogs

# MONGO--port 27020

Add shards

mongos> use adminmongos> sh.addshard ("test166:27017") mongos> Sh.addshard ("test167:27017")

Confirm

Mongos> Db.runcommand ({listshards:1})

2.6 Opening Shards

Turn on sharding for the specified library

Mongos> sh.enablesharding ("new")

Specify the slice key for the Shard

There are two modes of the tablet key: hash mode, Range mode

2.6.1 using hash mode sharding

Mongos> sh.shardcollection ("New.person", {"_id": "Hashed"})

Insert Data Acknowledgement

Mongos> use newmongos> for (Var i=0;i<10;i++) {Db.person.insert ({name: "Bluejoe" +i});

Use hash mode to record the average distribution on each slice

2.6.2 using range mode sharding

Mongos> sh.shardcollection ("New.person2", {"name": 1})

Insert Data Acknowledgement

Mongos> use newmongos> for (Var i=0;i<100;i++) {Db.person2.insert ({name: "Jack" +i});

2.7 Confirm Shard Condition

Mongos> sh.status () or mongos> db.printshardingstatus ()

Confirm data distribution on each shard (hash mode)

> Use new> db.person.find ()

Distribution of data on test166:27017

Distribution of data on test167:27017

2.8 Other

If the library you want to Shard has data, first build index and then specify the slice key

Mongos> sh.enablesharding ("New2") mongos> use new2mongos> db.user2.createIndex ({"username": 1}) mongos> Sh.shardcollection ("New2.user2", {"username": 1})

3. PostScript

This test environment is made up of a MongoDB single, no replica set is used, and the Shard configuration when using the replica set is similar to the one above, not detailed here.

MongoDB Series (iii): MongoDB Shard