A summary of the commands for MongoDB manual sharding

Operations for manual sharding

Automatic sharding can result in degraded performance. Therefore, it is reasonable to use manual shards. and use with tag together.

# for 4 shard programs, pre-processed instructions
1. Join the Shard server
Sh.addshard ("192.168.1.60:27017")
Sh.addshard ("192.168.1.61:27017")
Sh.addshard ("192.168.1.62:27017")
Sh.addshard ("192.168.1.63:27017")

2. Start the collection shard and specify the Sharding key
Db.location.ensureIndex ({"HostID": 1})
Sh.enablesharding ("MyDB")
Sh.shardcollection ("Mydb.location", {"HostID": 1})

Run Sh.status ()

{"_id": "MyDB", "partitioned": true, "PRIMARY": "Shard0003"}
Mydb.location
Shard key: {"HostID": 1}
Chunks
shard00031
{"HostID": {"$minKey": 1}}-->> {"HostID": {"$maxKey": 1}} on:shard0003 Timestamp (1, 0)

Sh.addshardtag ("shard0000", "TAG0")
Sh.addshardtag ("shard0001", "TAG1")
Sh.addshardtag ("shard0002", "TAG2")
Sh.addshardtag ("shard0003", "TAG3")

# Specific operation
1. Join Tagrange,
Join two +
Sh.addtagrange ("Mydb.location", {hostid: "0000000"}, {hostid: "3100000"}, "TAG0")
Sh.addtagrange ("Mydb.location", {hostid: "3100000"}, {hostid: "3200000"}, "TAG1")

Due to the current primary bit shard0003,
Sh.addtagrange ("Mydb.location", {hostid: "3200000"}, {hostid: "3300000"}, "TAG2")
Sh.addtagrange ("Mydb.location", {hostid: "3300000"}, {hostid: "3500000"}, "TAG3")
Sh.addtagrange ("Mydb.location", {hostid: "3500000"}, {$maxKey: 1}, "TAG3")

4. Add Chunck
Put the primary on the second shard
Db.runcommand ({moveprimary: "MyDB", To: "shard0001"})
View Shard Condition
Db.chunks.find ({ns: "Mydb.location"})

Manually establishing an empty chunk
for (var x=300; x<350; x + +) {
var prefix = String (x*10000);
Sh.splitat ("Mydb.location", {"HostID":p Refix})
}

Then move the chunk to the corresponding place, move the chunk command
Sh.movechunk ("Mydb.location", {hostid: "3000000"}, "shard0000")

==shard0000
for (var x=300; x<310; x + +) {
var prefix = String (x*10000);
Sh.movechunk ("Mydb.location", {"HostID":p Refix}, "shard0000")
}

==shard0001 310-320
==shard0002 320-330
==shard0003 330-350

Some other query operations
Find data that is greater than 340000, and
Db.chunks.find ({ns: "mydb.location", min:{$gte: {"HostID": "3400000"}})

Db.getsiblingdb ("admin"). RunCommand ({movechunk: "Mydb.location",
Find: {"HostID": "3400000"},
To: "Shard0003"})

1. Building an Index
Use MyDB
Db.location.ensureIndex ({"HostID": 1})
Db.location.ensureIndex ({"Postime": 1})
Db.location.ensureIndex ({"Hostno": 1})
Db.location.createIndex ({loc: "2dsphere"})

Db.location.ensureIndex ({"Postime": 1, "loc": "2dsphere"})
Db.location.ensureIndex ({"Postime": 1, "Hostno": 1, "loc": "2dsphere"})
Db.location.getIndexes ()

A summary of the commands for MongoDB manual sharding