MongoDB_Replica

Running Mongo DB Replica Set on three different server by Docker Swarm.

The oplog size sets to 3 MB, because of 5% of free disk space.

Initialize Manager Node

docker swarm init --listen-addr *manager-ip:2377* --advertise-addr *manager-ip*

Output

$ docker swarm init --advertise-addr *manager-ip*
Swarm initialized: current node (wvkk65249ch286431df31) is now a manager.

To add a worker to this swarm, run the following command:

    docker swarm join \
    --token *token* \
    *manager-ip*

To add a manager to this swarm, run 'docker swarm join-token manager' and follow the instructions.

Join Worker Nodes into network

docker swarm join --token *token* *manager-ip*

Setup Mongo DB on each node

First, you should update label on each node :

ssh <-- The manager node server -->
docker node update --label-add replica=1 *manager-ip*
docker node update --label-add replica=2 *worker1-ip*
docker node update --label-add replica=3 *worker2-ip*

Second, deploy service on manager node :

ssh <-- The manager node server -->
docker stack deploy -c docker-stack.yml overlay

And, you should login Manager node and run the under command :

./initiate.sh

# // if publish port was set before, need to remove first and update it.
# docker service update --publish-rm 27017:27017 mongo_replica_mongo1

docker service update --publish-add 27017:27017 mongo_replica_mongo1

Persistent storage

Data is stored at Docker Swarm Volume, if you want to check the Mountpoint on physical machine. Running the following command:

docker volume inspect *service name*

Data will be persistent between service runs. To remove docker stack and all data. Run the following command:

docker stack rm overlay
docker volume rm $(docker volume ls -qf label=com.docker.stack.namespace=mongo_replica)

Leave smarm mode

docker swarm leave

Run example project

Let's run Koalab :

docker service create --env 'MONGO_URL=mongodb://mongo1:27017,mongo2:27017,mongo3:27017/koalab?replicaSet=rs1' --name koalab --network mongo --replicas 2 --publish 8080:8080 kalahari/koalab

Reference

• Docker Swarm Document
• Learning note about Docker Swarm Mode
• Mongo Documentation - mongod
• Running a MongoDB Replica Set on Docker 1.12 Swarm Mode: Step by Step

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Support

Contributing

1. Fork it !
2. Create your feature branch : git checkout -b my-new-feature
3. Commit your changes : git commit -am 'Add some feature'
4. Push to the branch : git push origin my-new-feature
5. Submit a pull request :D

Issues

Each project may have many problems. Contributing to the better development of this project by reporting them.