MongoDB partitioned cluster

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summary

Sharding is a method to distribute data across multiple machines. MongoDB uses sharding to support deployment with very large data sets and high-throughput operations.

Sharding refers to the process of splitting data and distributing it on different machines. Partitioning is sometimes used to represent this concept. By distributing data to different machines, we can store more data and handle more load without a powerful mainframe computer.

Database systems with large datasets or high-throughput applications can challenge the capacity of a single server. For example, a high query rate will deplete the CPU capacity of the server. Working set sizes larger than the RAM of the system emphasize the I / O capacity of disk drives.

There are two ways to solve system growth: vertical expansion and horizontal expansion.

Vertical expansion means increasing the capacity of a single server, such as using a more powerful CPU, adding more RAM or increasing the amount of storage space. The limitations of available technologies may limit the ability of a single machine to be powerful enough for a given workload. In addition, cloud based providers have a hard upper limit based on the available hardware configurations. As a result, vertical scaling has an actual maximum.
Horizontal expansion means dividing the system dataset and loading multiple servers, and adding other servers to increase capacity as needed. Although the overall speed or capacity of a single machine may not be high, each machine processing a subset of the entire workload may provide higher efficiency than a single high-speed high-capacity server. Expanding deployment capacity requires only adding additional servers as needed, which may be lower than the overall cost of high-end hardware for a single machine. MongoDB supports horizontal expansion through sharding.

assembly

The MongoDB sharded cluster consists of the following components:

Sharding (storage): each shard contains a subset of shard data. Each shard can be deployed as a replica set.
Mongos (routing): mongos acts as a query router and provides an interface between client applications and fragmented clusters.
config servers: configure the metadata and configuration settings of the server storage cluster. From mongodb3 Starting with 4, you must deploy the configuration server as a replica set (CSRS)

The following figure describes the interaction of components in a fragmented cluster:

MongoDB partitions the data at the set level and distributes the set data on the partitions in the cluster.

example

Two fragment node replica sets (3 + 3) + one configuration node replica set (3) + two routing nodes (2), a total of 11 service nodes.

Creating a replica set of sharded nodes

All configuration files are placed directly in sharded_ Under the corresponding subdirectory of cluster, the default configuration file name is mongod conf

First replica set

1. Prepare the directory for storing data and logs

#-----------myshardrs01 
mkdir -p /mongodb/sharded_cluster/myshardrs01_27018/log \ & 
mkdir -p /mongodb/sharded_cluster/myshardrs01_27018/data/db \ & 
mkdir -p /mongodb/sharded_cluster/myshardrs01_27118/log \ & 
mkdir -p /mongodb/sharded_cluster/myshardrs01_27118/data/db \ & 
mkdir -p /mongodb/sharded_cluster/myshardrs01_27218/log \ & 
mkdir -p /mongodb/sharded_cluster/myshardrs01_27218/data/db

2. Create or modify a configuration file: VIM / mongodb / shared_ cluster/myshardrs01_ 27018/mongod. conf

systemLog: 
  #The destination of all log output sent by MongoDB is specified as a file 
  destination: file
  #The path of the log file to which mongod or mongos should send all diagnostic logging information 
  path: "/mongodb/sharded_cluster/myshardrs01_27018/log/mongod.log" 
  #When the mongos or mongod instance restarts, mongos or mongod appends a new entry to the end of the existing log file. 
  logAppend: true 
storage: 
  #The directory where the mongod instance stores its data. storage. The dbpath setting applies only to mongod. 
  dbPath: "/mongodb/sharded_cluster/myshardrs01_27018/data/db" 
  journal: 
    #Enable or disable persistent logging to ensure that data files remain valid and recoverable. 
    enabled: true 
processManagement: 
  #Enable daemon mode for running mongos or mongod processes in the background. 
  fork: true 
  #Specifies the file location where the process ID of the mongos or mongod process is saved, where mongos or mongod will write its PID 
  pidFilePath: "/mongodb/sharded_cluster/myshardrs01_27018/log/mongod.pid" 
net:
  #The service instance binds all IPS, which has side effects. When the replica set is initialized, the node name will be automatically set to the local domain name instead of IP 
  #bindIpAll: true 
  #IP address bound by the service instance 
  bindIp: localhost,192.168.0.2 
  #bindIp 
  #Bound port 
  port: 27018 
replication: 
  #The name of the replica set 
  replSetName: myshardrs01 
sharding: 
  #Slice role 
  clusterRole: shardsvr

sharding.clusterRole:


Value	Description
configsvr	Start this instance as a config server. The instance starts on port 27019 by default.
shardsvr	Start this instance as a shard. The instance starts on port 27018 by default.

be careful:

Setting sharding Clusterrole requires mongod instance to run replication. To deploy an instance as a replica set member, use

replSetName sets and specifies the name of the replica set.

3. Create or modify a configuration file: VIM / mongodb / shared_ cluster/myshardrs01_ 27118/mongod. conf

systemLog: 
  #The destination of all log output sent by MongoDB is specified as a file 
  destination: file
  #The path of the log file to which mongod or mongos should send all diagnostic logging information 
  path: "/mongodb/sharded_cluster/myshardrs01_27118/log/mongod.log" 
  #When the mongos or mongod instance restarts, mongos or mongod appends a new entry to the end of the existing log file. 
  logAppend: true 
storage: 
  #The directory where the mongod instance stores its data. storage. The dbpath setting applies only to mongod. 
  dbPath: "/mongodb/sharded_cluster/myshardrs01_27118/data/db" 
  journal: 
    #Enable or disable persistent logging to ensure that data files remain valid and recoverable. 
    enabled: true 
processManagement: 
  #Enable daemon mode for running mongos or mongod processes in the background. 
  fork: true 
  #Specifies the file location where the process ID of the mongos or mongod process is saved, where mongos or mongod will write its PID 
  pidFilePath: "/mongodb/sharded_cluster/myshardrs01_27118/log/mongod.pid" 
net:
  #The service instance binds all IPS, which has side effects. When the replica set is initialized, the node name will be automatically set to the local domain name instead of IP 
  #bindIpAll: true 
  #IP address bound by the service instance 
  bindIp: localhost,192.168.0.2 
  #bindIp 
  #Bound port 
  port: 27118 
replication: 
  #The name of the replica set 
  replSetName: myshardrs01 
sharding: 
  #Slice role 
  clusterRole: shardsvr

4. Create or modify a configuration file: VIM / mongodb / shared_ cluster/myshardrs01_ 27218/mongod. conf

systemLog: 
  #The destination of all log output sent by MongoDB is specified as a file 
  destination: file
  #The path of the log file to which mongod or mongos should send all diagnostic logging information 
  path: "/mongodb/sharded_cluster/myshardrs01_27218/log/mongod.log" 
  #When the mongos or mongod instance restarts, mongos or mongod appends a new entry to the end of the existing log file. 
  logAppend: true 
storage: 
  #The directory where the mongod instance stores its data. storage. The dbpath setting applies only to mongod. 
  dbPath: "/mongodb/sharded_cluster/myshardrs01_27218/data/db" 
  journal: 
    #Enable or disable persistent logging to ensure that data files remain valid and recoverable. 
    enabled: true 
processManagement: 
  #Enable daemon mode for running mongos or mongod processes in the background. 
  fork: true 
  #Specifies the file location where the process ID of the mongos or mongod process is saved, where mongos or mongod will write its PID 
  pidFilePath: "/mongodb/sharded_cluster/myshardrs01_27218/log/mongod.pid" 
net:
  #The service instance binds all IPS, which has side effects. When the replica set is initialized, the node name will be automatically set to the local domain name instead of IP 
  #bindIpAll: true 
  #IP address bound by the service instance 
  bindIp: localhost,192.168.0.2 
  #bindIp 
  #Bound port 
  port: 27218 
replication: 
  #The name of the replica set 
  replSetName: myshardrs01 
sharding: 
  #Segmented role 
  clusterRole: shardsvr

5. Start the first set of replica sets: one master, one replica and one arbitration

Start three mongod services in sequence:

/usr/yltrcc/mongodb/bin/mongod -f /mongodb/sharded_cluster/myshardrs01_27018/mongod.conf

/usr/yltrcc/mongodb/bin/mongod -f /mongodb/sharded_cluster/myshardrs01_27118/mongod.conf

/usr/yltrcc/mongodb/bin/mongod -f /mongodb/sharded_cluster/myshardrs01_27218/mongod.conf

6 initialize replica set and create master node

Use the client command to connect to any node, but try to connect to the master node: / usr/yltrcc/mongodb/bin/mongo --host 180.76.159.126 --port 27018

Execute command:

# Initialize replica set
> rs.initiate()

# View replica sets
myshardrs01:SECONDARY> rs.status()

# Master node configuration view
myshardrs01:PRIMARY> rs.conf()

7 add replica node and arbitration node

# Add slave node
myshardrs01:PRIMARY> rs.add("180.76.159.126:27118")

# Add quorum node
myshardrs01:PRIMARY> rs.addArb("180.76.159.126:27218")

# View configuration
myshardrs01:PRIMARY> rs.conf()

Second replica set

1. Prepare the directory for storing data and logs

#-----------myshardrs01 
mkdir -p /mongodb/sharded_cluster/myshardrs01_27318/log \ & 
mkdir -p /mongodb/sharded_cluster/myshardrs01_27318/data/db \ & 
mkdir -p /mongodb/sharded_cluster/myshardrs01_27418/log \ & 
mkdir -p /mongodb/sharded_cluster/myshardrs01_27418/data/db \ & 
mkdir -p /mongodb/sharded_cluster/myshardrs01_27518/log \ & 
mkdir -p /mongodb/sharded_cluster/myshardrs01_27518/data/db

2. Create or modify a configuration file: VIM / mongodb / shared_ cluster/myshardrs01_ 27318/mongod. conf

systemLog: 
  #The destination of all log output sent by MongoDB is specified as a file 
  destination: file
  #The path of the log file to which mongod or mongos should send all diagnostic logging information 
  path: "/mongodb/sharded_cluster/myshardrs01_27318/log/mongod.log" 
  #When the mongos or mongod instance restarts, mongos or mongod appends a new entry to the end of the existing log file. 
  logAppend: true 
storage: 
  #The directory where the mongod instance stores its data. storage. The dbpath setting applies only to mongod. 
  dbPath: "/mongodb/sharded_cluster/myshardrs01_27318/data/db" 
  journal: 
    #Enable or disable persistent logging to ensure that data files remain valid and recoverable. 
    enabled: true 
processManagement: 
  #Enable daemon mode for running mongos or mongod processes in the background. 
  fork: true 
  #Specifies the file location where the process ID of the mongos or mongod process is saved, where mongos or mongod will write its PID 
  pidFilePath: "/mongodb/sharded_cluster/myshardrs01_27318/log/mongod.pid" 
net:
  #The service instance binds all IPS, which has side effects. When the replica set is initialized, the node name will be automatically set to the local domain name instead of IP 
  #bindIpAll: true 
  #IP address bound by the service instance 
  bindIp: localhost,192.168.0.2 
  #bindIp 
  #Bound port 
  port: 27318 
replication: 
  #The name of the replica set 
  replSetName: myshardrs01 
sharding: 
  #Slice role 
  clusterRole: shardsvr

3. Create or modify a configuration file: VIM / mongodb / shared_ cluster/myshardrs01_ 27418/mongod. conf

systemLog: 
  #The destination of all log output sent by MongoDB is specified as a file 
  destination: file
  #The path of the log file to which mongod or mongos should send all diagnostic logging information 
  path: "/mongodb/sharded_cluster/myshardrs01_27418/log/mongod.log" 
  #When the mongos or mongod instance restarts, mongos or mongod appends a new entry to the end of the existing log file. 
  logAppend: true 
storage: 
  #The directory where the mongod instance stores its data. storage. The dbpath setting applies only to mongod. 
  dbPath: "/mongodb/sharded_cluster/myshardrs01_27418/data/db" 
  journal: 
    #Enable or disable persistent logging to ensure that data files remain valid and recoverable. 
    enabled: true 
processManagement: 
  #Enable daemon mode for running mongos or mongod processes in the background. 
  fork: true 
  #Specifies the file location where the process ID of the mongos or mongod process is saved, where mongos or mongod will write its PID 
  pidFilePath: "/mongodb/sharded_cluster/myshardrs01_27418/log/mongod.pid" 
net:
  #The service instance binds all IPS, which has side effects. When the replica set is initialized, the node name will be automatically set to the local domain name instead of IP 
  #bindIpAll: true 
  #IP address bound by the service instance 
  bindIp: localhost,192.168.0.2 
  #bindIp 
  #Bound port 
  port: 27418 
replication: 
  #The name of the replica set 
  replSetName: myshardrs01 
sharding: 
  #Slice role 
  clusterRole: shardsvr

4. Create or modify a configuration file: VIM / mongodb / shared_ cluster/myshardrs01_ 27518/mongod. conf

systemLog: 
  #The destination of all log output sent by MongoDB is specified as a file 
  destination: file
  #The path of the log file to which mongod or mongos should send all diagnostic logging information 
  path: "/mongodb/sharded_cluster/myshardrs01_27518/log/mongod.log" 
  #When the mongos or mongod instance restarts, mongos or mongod appends a new entry to the end of the existing log file. 
  logAppend: true 
storage: 
  #The directory where the mongod instance stores its data. storage. The dbpath setting applies only to mongod. 
  dbPath: "/mongodb/sharded_cluster/myshardrs01_27518/data/db" 
  journal: 
    #Enable or disable persistent logging to ensure that data files remain valid and recoverable. 
    enabled: true 
processManagement: 
  #Enable daemon mode for running mongos or mongod processes in the background. 
  fork: true 
  #Specifies the file location where the process ID of the mongos or mongod process is saved, where mongos or mongod will write its PID 
  pidFilePath: "/mongodb/sharded_cluster/myshardrs01_27518/log/mongod.pid" 
net:
  #The service instance binds all IPS, which has side effects. When the replica set is initialized, the node name will be automatically set to the local domain name instead of IP 
  #bindIpAll: true 
  #IP address bound by the service instance 
  bindIp: localhost,192.168.0.2 
  #bindIp 
  #Bound port 
  port: 27518 
replication: 
  #The name of the replica set 
  replSetName: myshardrs01 
sharding: 
  #Slice role 
  clusterRole: shardsvr

5. Start the first set of replica sets: one master, one replica and one arbitration

Start three mongod services in sequence:

/usr/yltrcc/mongodb/bin/mongod -f /mongodb/sharded_cluster/myshardrs01_27318/mongod.conf

/usr/yltrcc/mongodb/bin/mongod -f /mongodb/sharded_cluster/myshardrs01_27418/mongod.conf

/usr/yltrcc/mongodb/bin/mongod -f /mongodb/sharded_cluster/myshardrs01_27518/mongod.conf

6 initialize replica set and create master node

Use the client command to connect to any node, but try to connect to the master node: / usr/yltrcc/mongodb/bin/mongo --host 180.76.159.126 --port 27318

Execute command:

# Initialize replica set
> rs.initiate()

# View replica sets
myshardrs01:SECONDARY> rs.status()

# Master node configuration view
myshardrs01:PRIMARY> rs.conf()

7 add replica node and arbitration node

# Add slave node
myshardrs01:PRIMARY> rs.add("180.76.159.126:27418")

# Add quorum node
myshardrs01:PRIMARY> rs.addArb("180.76.159.126:27518")

# View configuration
myshardrs01:PRIMARY> rs.conf()

Configure node replica set creation

1. Prepare the directory for storing data and logs

#-----------myshardrs01 
mkdir -p /mongodb/sharded_cluster/myconfigrs_27019/log \ & 
mkdir -p /mongodb/sharded_cluster/myconfigrs_27019/data/db \ & 
mkdir -p /mongodb/sharded_cluster/myconfigrs_27119/log \ & 
mkdir -p /mongodb/sharded_cluster/myconfigrs_27119/data/db \ & 
mkdir -p /mongodb/sharded_cluster/myconfigrs_27219/log \ & 
mkdir -p /mongodb/sharded_cluster/myconfigrs_27219/data/db

2. Create or modify a configuration file: VIM / mongodb / shared_ cluster/myconfigrs_ 27019/mongod. conf

systemLog: 
  #The destination of all log output sent by MongoDB is specified as a file 
  destination: file
  #The path of the log file to which mongod or mongos should send all diagnostic logging information 
  path: "/mongodb/sharded_cluster/myconfigrs_27019/log/mongod.log" 
  #When the mongos or mongod instance restarts, mongos or mongod appends a new entry to the end of the existing log file. 
  logAppend: true 
storage: 
  #The directory where the mongod instance stores its data. storage. The dbpath setting applies only to mongod. 
  dbPath: "/mongodb/sharded_cluster/myconfigrs_27019/data/db" 
  journal: 
    #Enable or disable persistent logging to ensure that data files remain valid and recoverable. 
    enabled: true 
processManagement: 
  #Enable daemon mode for running mongos or mongod processes in the background. 
  fork: true 
  #Specifies the file location where the process ID of the mongos or mongod process is saved, where mongos or mongod will write its PID 
  pidFilePath: "/mongodb/sharded_cluster/myconfigrs_27019/log/mongod.pid" 
net:
  #The service instance binds all IPS, which has side effects. When the replica set is initialized, the node name will be automatically set to the local domain name instead of IP 
  #bindIpAll: true 
  #IP address bound by the service instance 
  bindIp: localhost,192.168.0.2 
  #bindIp 
  #Bound port 
  port: 27019 
replication: 
  #The name of the replica set 
  replSetName: myconfigrs
sharding: 
  #Slice role 
  clusterRole: configsvr

3. Create or modify a configuration file: VIM / mongodb / shared_ cluster/myconfigrs_ 27119/mongod. conf

systemLog: 
  #The destination of all log output sent by MongoDB is specified as a file 
  destination: file
  #The path of the log file to which mongod or mongos should send all diagnostic logging information 
  path: "/mongodb/sharded_cluster/myconfigrs_27119/log/mongod.log" 
  #When the mongos or mongod instance restarts, mongos or mongod appends a new entry to the end of the existing log file. 
  logAppend: true 
storage: 
  #The directory where the mongod instance stores its data. storage. The dbpath setting applies only to mongod. 
  dbPath: "/mongodb/sharded_cluster/myconfigrs_27119/data/db" 
  journal: 
    #Enable or disable persistent logging to ensure that data files remain valid and recoverable. 
    enabled: true 
processManagement: 
  #Enable daemon mode for running mongos or mongod processes in the background. 
  fork: true 
  #Specifies the file location where the process ID of the mongos or mongod process is saved, where mongos or mongod will write its PID 
  pidFilePath: "/mongodb/sharded_cluster/myconfigrs_27119/log/mongod.pid" 
net:
  #The service instance binds all IPS, which has side effects. When the replica set is initialized, the node name will be automatically set to the local domain name instead of IP 
  #bindIpAll: true 
  #IP address bound by the service instance 
  bindIp: localhost,192.168.0.2 
  #bindIp 
  #Bound port 
  port: 27119
replication: 
  #The name of the replica set 
  replSetName: myconfigrs
sharding: 
  #Slice role 
  clusterRole: configsvr

4. Create or modify a configuration file: VIM / mongodb / shared_ cluster/myconfigrs_ 27219/mongod. conf

systemLog: 
  #The destination of all log output sent by MongoDB is specified as a file 
  destination: file
  #The path of the log file to which mongod or mongos should send all diagnostic logging information 
  path: "/mongodb/sharded_cluster/myconfigrs_27219/log/mongod.log" 
  #When the mongos or mongod instance restarts, mongos or mongod appends a new entry to the end of the existing log file. 
  logAppend: true 
storage: 
  #The directory where the mongod instance stores its data. storage. The dbpath setting applies only to mongod. 
  dbPath: "/mongodb/sharded_cluster/myconfigrs_27219/data/db" 
  journal: 
    #Enable or disable persistent logging to ensure that data files remain valid and recoverable. 
    enabled: true 
processManagement: 
  #Enable daemon mode for running mongos or mongod processes in the background. 
  fork: true 
  #Specifies the file location where the process ID of the mongos or mongod process is saved, where mongos or mongod will write its PID 
  pidFilePath: "/mongodb/sharded_cluster/myconfigrs_27219/log/mongod.pid" 
net:
  #The service instance binds all IPS, which has side effects. When the replica set is initialized, the node name will be automatically set to the local domain name instead of IP 
  #bindIpAll: true 
  #IP address bound by the service instance 
  bindIp: localhost,192.168.0.2 
  #bindIp 
  #Bound port 
  port: 27219 
replication: 
  #The name of the replica set 
  replSetName: myconfigrs
sharding: 
  #Slice role 
  clusterRole: configsvr

5. Start the first set of replica sets: one master, one replica and one arbitration

Start three mongod services in sequence:

/usr/yltrcc/mongodb/bin/mongod -f /mongodb/sharded_cluster/myconfigrs_27019/mongod.conf

/usr/yltrcc/mongodb/bin/mongod -f /mongodb/sharded_cluster/myconfigrs_27119/mongod.conf

/usr/yltrcc/mongodb/bin/mongod -f /mongodb/sharded_cluster/myconfigrs_27219/mongod.conf

6 initialize replica set and create master node

Use the client command to connect to any node, but try to connect to the master node: / usr/yltrcc/mongodb/bin/mongo --host 180.76.159.126 --port 27219

Execute command:

# Initialize replica set
> rs.initiate()

# View replica sets
myshardrs01:SECONDARY> rs.status()

# Master node configuration view
myshardrs01:PRIMARY> rs.conf()

7 add two replica nodes

# Add slave node
myshardrs01:PRIMARY> rs.add("180.76.159.126:27119")
myshardrs01:PRIMARY> rs.add("180.76.159.126:27219")

# View configuration
myshardrs01:PRIMARY> rs.conf()

Creation of routing node

First routing node

1. Prepare the directory for storing data and logs

#-----------mongos01
mkdir -p /mongodb/sharded_cluster/mymongos_27017/log

2. Create or modify a configuration file: VI / mongodb / shared_ cluster/mymongos_ 27017/mongos. conf

systemLog: 
  #The destination of all log output sent by MongoDB is specified as a file 
  destination: file
  #The path of the log file to which mongod or mongos should send all diagnostic logging information 
  path: "/mongodb/sharded_cluster/mymongos_27017/log/mongod.log" 
  #When the mongos or mongod instance restarts, mongos or mongod appends a new entry to the end of the existing log file. 
  logAppend: true 
storage: 
  #The directory where the mongod instance stores its data. storage. The dbpath setting applies only to mongod. 
  dbPath: "/mongodb/sharded_cluster/mymongos_27017/data/db" 
  journal: 
    #Enable or disable persistent logging to ensure that data files remain valid and recoverable. 
    enabled: true 
processManagement: 
  #Enable daemon mode for running mongos or mongod processes in the background. 
  fork: true 
  #Specifies the file location where the process ID of the mongos or mongod process is saved, where mongos or mongod will write its PID 
  pidFilePath: "/mongodb/sharded_cluster/mymongos_27017/log/mongod.pid" 
net:
  #The service instance binds all IPS, which has side effects. When the replica set is initialized, the node name will be automatically set to the local domain name instead of IP 
  #bindIpAll: true 
  #IP address bound by the service instance 
  bindIp: localhost,192.168.0.2 
  #bindIp 
  #Bound port 
  port: 27017 
sharding: 
  #Specifies the configuration node replica set 
  configDB: myconfigrs/180.76.159.126:27019,180.76.159.126:27119,180.76.159.126:27219

3. Start mongod service:

/usr/yltrcc/mongodb/bin/mongod -f /mongodb/sharded_cluster/mymongos_27017/mongos.conf

4 client login mongos: /usr/yltrcc/mongodb/bin/mongo --host 180.76.159.126 --port 27017

Through the routing node operation, only the configuration node is connected, and the fragmented data node is not connected, so the service data cannot be written.

5. Perform slice configuration on the routing node

Add shard: sh.addShard("IP:Port")

# Add first replica set
sh.addShard("myshardrs01/192.168.0.2:27018,180.76.159.126:27118,180.76.159.126:2 7218")

# Add second replica set
sh.addShard("myshardrs02/192.168.0.2:27318,180.76.159.126:27418,180.76.159.126:2 7518")

Tip: if adding shards fails, you need to manually remove the shards, check the correctness of the information about adding shards, and then add the shards again.

Remove slice reference (understand):

use admin 
db.runCommand( { removeShard: "myshardrs02" } )

Enable sharding functions: sh.enableSharding("library name"), sh.shardCollection("library name. Collection name", {"key":1})

Configuring sharding in the articledb database on mongos

sh.enableSharding("articledb")

# View slice status
 sh.status()

Set sharding: for set sharding, you must use the sh.shardCollection() method to specify the set and sharding keys.

Syntax format: sh.shardCollection(namespace, key, unique)

Parameter Description:


Parameter	Type	Description
namespace	string	Namespace of the target collection to be shared (sharded), format: < Database >< collection>
key	document	An index specification document used as a shard key. The shard key determines how MongoDB distributes documents between Shards. Unless the collection is empty, the index must exist before the shard collection command. If the set is empty, MongoDB creates an index before sharding the set, provided that the index supporting sharding key does not exist. Simply put: it consists of documents containing a field and the index traversal direction of the field.
unique	boolean	When the value is true, the slice key field is restricted to ensure that it is a unique index. Hash policy slice keys do not support unique indexes. The default is false.

6 insert data test after slicing

7 add another routing node

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Keywords: Back-end

Added by ofirf96 on Wed, 19 Jan 2022 13:01:48 +0200

Programming VIP

MongoDB partitioned cluster

One sentence a day

summary

assembly

example

Creating a replica set of sharded nodes

First replica set

Second replica set

Configure node replica set creation

Creation of routing node

First routing node

Beautiful sentences

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