MongoDB Upgrade Procedure

In-Depth: https://docs.mongodb.com/manual/release-notes/4.4-upgrade-standalone/

Always update step by step

• Check feature capabilities are set correctly in authenticated mongo shell db.adminCommand( { getParameter: 1, featureCompatibilityVersion: 1 } ) => should be old version
• Stop mongod
• Download new mongo version into ~/mongodb/sources wget https://fastdl.mongodb.org/linux/mongodb-linux-x86_64-ubuntu1604-4.4.0.tgz
• Extract tar xfz mongodb-linux-x86_64-ubuntu1604-4.4.0.tgz && rm mongodb-linux-x86_64-ubuntu1604-4.4.0.tgz
• Update symlink in ~/mongodb rm mongo && ln -s sources/mongodb-linux-x86_64-ubuntu1604-4.4.0/ mongo
• Check versions of mongo and mongod with --version
• Start mongod
• Set new feature capabilities in authenticated mongo shell db.adminCommand( { setFeatureCompatibilityVersion: "4.4" } )
• Check feature capabilities are set correctly in authenticated mongo shell db.adminCommand( { getParameter: 1, featureCompatibilityVersion: 1 } ) => should be new version