AWS Glue Unable to Connect to MongoDB on EC2 — Simple Fix

Problem

While working on AWS Glue jobs for our Customer Data Platform, we needed to connect Glue to a MongoDB database hosted on an EC2 instance in the same AWS account.

Here is a diagram of the use case: Use Case Diagram

Even after configuring:

  • Correct VPC and subnet
  • Security groups (allowing traffic as per AWS docs)
  • MongoDB (unmanaged) Glue connector

…the Glue job kept failing with a connection timeout.

We initially used the MongoDB (unmanaged) connector provided by AWS Glue and configured all required networking details.
Despite everything looking correct, the connection never succeeded.

Resolution

Instead of using the MongoDB-specific connector, we switched to a Network-type Glue connection.

Since the MongoDB URI was already defined inside the Glue script, only basic network access was required.

Steps:

  1. Go to AWS Glue → Data Connections
  2. Create a new connection
  3. Select Data source = Network
  4. Configure the same:
    • VPC
    • Subnet
    • Security group (used by MongoDB EC2)

Attach this Network connection to the Glue job.

I was able to connect to MongoDB successfully with this approach.

Key Takeaway

If your MongoDB connection string is already handled in the Glue script,
using a Network connection is simpler and more reliable than the MongoDB connector.

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