dwmkerr.com

The mongo-monitor CLI is a lean and simple tool to check the status of a MongoDB server or cluster. The code is on GitHub: github.com/dwmkerr/mongo-monitor Here’s how it looks in action: In this animation I am monitoring a simple sharded cluster, and running some example maintenance operations, adding a node to a replicaset, stepping down a primary and shutting down a replicaset node. A simple CLI which shows the status in real-time can be very useful to keep open when performing admin, letting you see how your changes affect the cluster as you work on it.

tl;dr? Check your mongodb.conf bind_ip settings to make sure that you’re not allowing connections only from localhost. This may just end up being the first part of a wider troubleshooting guide, but this is one I’ve spent a few hours fixing, after assuming I was making terrible mistakes with my security groups. If you find you cannot connect to your MongoDB server from an EB app server (or anything for that matter), before you spend ages checking your Elastic IP, VPC and Security Group config, don’t forget that you may have simply used bind_ip in your config file.