Import and Export using OPLOG.RS in MongoDB

Edit mongod.conf  to add replicate set

sudo vi /etc/mongod.conf

Add this following lines in mongod.conf

replication:
  replSetName: rs0
  oplogSizeMB: 1024

Then restart mongod by "sudo service mongod restart"

Check for mongo status if everything is fine

sudo service mongod status

if everything is OK you get this result otherwise please check/var/log/mongodb/mongod.log for any errors.

mongod start/running, process 5806

Now go to Shell prompt and type 

>mongo

Then type

> use  //To change your working DB

> rs.initiate()

{

"info2" : "no configuration explicitly specified -- making one",

"me" : "jamesnirmal:27017",

"ok" : 1

}

Now command prompt will changed to 

rs0:PRIMARY>

Now type

rs0:PRIMARY> use local

rs0:PRIMARY> show collections

me

oplog.rs

startup_log

system.indexes

system.replset

MongoRestore:

Now go to Normal shell and create one folder called oplog

and type this following command to create mongo dump under oplog folder.

mongodump --port 27017 -d local -c oplog.rs --query '{"ts" : {$gte: Timestamp(1502285060, 1)}}' -o ./oplog/

Then type cd oplog/local/

mv oplog.rs.bson oplog.bson

rm oplog.rs.metadata.json //if exist

run this command to Destintion server all data will be updated automatically

mongorestore --port 27017 --oplogReplay ./oplog/local/

To verify your changes please type ;

 db..find();