How to configure a MongoDB cluster which supports sessions?

Question

I want to explore the new transaction feature of MongoDB and use Spring Data MongoDB. However, I get the exception message \"Sessions are not supported by the MongoDB cl

Answer 1

Replica set is the resolution for the issue for sure

But doing replica of 3 nodes is not mandatory.

Solution 1 (for standalone setup)

For standalone mongo installation you can skip configuring 2nd or 3rd node as described on the official mongo documentations here

And you'll need to set a replSetName in the configuration

replication:
   oplogSizeMB: 
   replSetName: 
   enableMajorityReadConcern: 

and then run details of which are here

rs.initiate()

after this the connection string would be like below:-

mongodb://localhost:27017/?replicaSet=

keys above that you need to replace:-

database_name = name of the database

replSet_Name = name of the replica set you setup in the above configuration

Solution 2 (only for docker based requirement)

Example Docker image with single node replica set acting as primary node for development environment is as below:-

I had hosted the docker image on the docker hub

docker pull krnbr/mongo:latest

Contents of the same Dockerfile are below:-

FROM mongo
RUN echo "rs.initiate({'_id':'rs0','members':[{'_id':0,'host':'127.0.0.1:27017'}]});" > /docker-entrypoint-initdb.d/replica-init.js
RUN cat /docker-entrypoint-initdb.d/replica-init.js
CMD [ "--bind_ip_all", "--replSet", "rs0" ]

Docker run command (replace with the image name that you build yoursef or use the on shared above i.e krnbr/mongo):-

without volume

docker run -d --name mongo -p 27017:27017  mongod --replSet rs0 --port 27017

with volume

docker run -d --name mongo -p 27017:27017 -v ~/.mongodb:/data/db  mongod --replSet rs0 --port 27017

for supporting binding of any ip

docker run -d --name mongo -p 27017:27017 -v ~/.mongodb:/data/db  mongod --bind_ip_all --replSet rs0 --port 27017