Required MongoDB versions can change across different major versions. It is very important that you choose the correct database version when deploying and also to make sure your existing installation is using a supported version.
Using release notes
You can always check the supported version list on our GitHub releases page.
Use the following "template" link to inspect the release notes and supported MongoDB releases.
If it is an existing deployment, being fairly in the middle of the supported list is a good idea. We know how hard it is to update our databases, especially if it's a large deployment.
If you're going to deploy fresh, we recommend choosing the latest version that is supported. For example, in case of Rocket.Chat version 4.5.0, for new deployments the recommended version would be 5.0. This will make sure you don't have to update the DB anytime soon.
One way you can get the latest MongoDB version that is supported by the current latest Rocket.Chat, is by using curl with jq:
We don't remove MongoDB support overnight. A version marked to be removed from support is first deprecated and you should see a deprecation warning not only in your Rocket.Chat logs but also the server admins should see a deprecation notice banner on their instances.
Note Without the MongoDB version we can't ensure you are running a compatible version. If you are running your mongodb with auth enabled and a user different from admin you may need to grant permissions for this user to check cluster data. You can do it via mongo shell running the following command replacing the string YOUR_USER by the correct user\'s name:
Mmapv1 is no longer supported in MongoDB since version 4.2. So to make sure you update your Rocket.Chat installations easily in the future, use the WiredTiger storage engine. If you're already running mmapv1, please migrate to wiredTiger as soon as possible.