MongoDB for Oracle DBA’s Part 7 : Adding a New Shard to existing Cluster in Standalone Server

In this post we will see how to Add a new shard shard2 and new replicaset rs1

• Create Directories
• Create Config Files
• Start the instances in replicaset rs1
• add the instances for replication to replicaset rs1
• add the replicaset rs1 to shard

The final diagram in my single host, Mongos , MongoC, MongoD with replicaset along with shards looks like this. Best way to practice isnt 🙂

### Create directories ###

Note: See the directory shard2 and replicaset rs1, the existing one was in shard1 and rs0.

### Shard1 with Primary & Two Secondaries ###

mkdir -p /backups/data/cluster/shard2/rs1/0/logs

mkdir -p /backups/data/cluster/shard2/rs1/0/data

mkdir -p /backups/data/cluster/shard2/rs1/1/logs

mkdir -p /backups/data/cluster/shard2/rs1/1/data

mkdir -p /backups/data/cluster/shard2/rs1/2/logs

mkdir -p /backups/data/cluster/shard2/rs1/2/data

### Create Configuration file for  node 1 , Note the port number & directory paths ###

Note: Look at the port numbers and replicaset name which is different than existing rs0 replicaset

vi /backups/data/cluster/shard2/rs0.conf

systemLog:

destination: file

path: "/backups/data/cluster/shard2/rs1/0/logs/rs1.log"

logAppend: true

processManagement:

pidFilePath: "/backups/data/cluster/shard2/rs1/0/shard2.pid"

fork: true

net:

bindIp: 127.0.0.1

port: 57018

storage:

engine: "mmapv1"

dbPath: "/backups/data/cluster/shard2/rs1/0/data"

directoryPerDB: true

operationProfiling:

mode: all

replication:

oplogSizeMB: 5120

replSetName: "rs1"

#### Create configuration file for node 2, Note the port number & directory paths ###

vi /backups/data/cluster/shard2/rs1.conf

systemLog:

destination: file

path: "/backups/data/cluster/shard2/rs1/1/logs/rs1.log"

logAppend: true

processManagement:

pidFilePath: "/backups/data/cluster/shard2/rs1/1/shard2.pid"

fork: true

net:

bindIp: 127.0.0.1

port: 57019

storage:

engine: "mmapv1"

dbPath: "/backups/data/cluster/shard2/rs1/1/data"

directoryPerDB: true

operationProfiling:

mode: all

replication:

oplogSizeMB: 5120

replSetName: "rs1"

#### Create configuration file for node 3, Note the port number & directory paths ###

vi /backups/data/cluster/shard2/rs2.conf

systemLog:

destination: file

path: "/backups/data/cluster/shard2/rs1/2/logs/rs1.log"

logAppend: true

processManagement:

pidFilePath: "/backups/data/cluster/shard2/rs1/2/shard2.pid"

fork: true

net:

bindIp: 127.0.0.1

port: 57020

storage:

engine: "mmapv1"

dbPath: "/backups/data/cluster/shard2/rs1/2/data"

directoryPerDB: true

operationProfiling:

mode: all

replication:

oplogSizeMB: 5120

replSetName: "rs1"

### Start the mongod instances in New Shard

mongod -f /backups/data/cluster/shard2/rs0.conf

mongod -f /backups/data/cluster/shard2/rs1.conf

mongod -f /backups/data/cluster/shard2/rs2.conf

### Add the instances to replicaset

MongoDB Enterprise mongos> mongo localhost:57018

MongoDB Enterprise mongos> rs.initiate({_id:"rs1", members: [{"_id":1, "host":"localhost:57018"},{"_id":2, "host":"localhost:57019"},{"_id":3, "host":"localhost:57020"}]})

MongoDB Enterprise mongos> rs.status()

### Add the replicat rs1 to shard2, log to mongos

MongoDB Enterprise mongos> mongo localhost:27017

MongoDB Enterprise mongos>  sh.addShard("rs1/localhost:57018,localhost:57019,localhost:57020");

MongoDB Enterprise mongos> sh.status()

--- Sharding Status ---

sharding version: {

"_id" : 1,

"minCompatibleVersion" : 5,

"currentVersion" : 6,

"clusterId" : ObjectId("5834e646a2c25f3b06d65226")

}

shards:

{  "_id" : "rs0",  "host" : "rs0/localhost:47018,localhost:47019,localhost:47020" }

{  "_id" : "rs1",  "host" : "rs1/localhost:57018,localhost:57019,localhost:57020" }

active mongoses:

"3.2.1" : 1

balancer:

Currently enabled:  yes

Currently running:  no

Failed balancer rounds in last 5 attempts:  0

Migration Results for the last 24 hours:

No recent migrations

databases:

{  "_id" : "mydb",  "primary" : "rs0",  "partitioned" : true }

}

### And finally mongo process looks like this in my standalone server

root@wash-i-03aaefdf-restore /backups/data/cluster/shard1/rs0/1/data/foo $ ps -eaf | grep mongo

root     21615     1  6 11:42 ?        00:02:28 mongod -f /backups/data/cluster/shard1/rs0.conf

root     21678     1  5 11:43 ?        00:01:56 mongod -f /backups/data/cluster/shard1/rs1.conf

root     21744     1  5 11:43 ?        00:01:52 mongod -f /backups/data/cluster/shard1/rs2.conf

root     21827     1  0 11:43 ?        00:00:07 mongod -f /backups/data/cluster/mongoc/mongoc.conf

root     21844     1  4 11:43 ?        00:01:29 mongos -f /backups/data/cluster/mongos/mongos.conf

root     22075     1  0 11:57 ?        00:00:05 mongod -f /backups/data/cluster/shard2/rs0.conf

root     22096     1  0 11:57 ?        00:00:04 mongod -f /backups/data/cluster/shard2/rs1.conf

root     22117     1  0 11:57 ?        00:00:04 mongod -f /backups/data/cluster/shard2/rs2.conf