How to set up Active Active configuration?

Summary: Guide for Configuring MDSS Active-Active Setup

Description: Below is a detailed guide to configure an Active-Active setup for MDSS, along with a recommended startup approach to ensure stability.

Step 1 — Deploy External Services

Set up the following services on dedicated servers (separate from MDSS nodes):

• PostgreSQL — Install and create the MDSS database and user

• RabbitMQ — Install and create a user with appropriate permissions

• Redis — Install and configure a password for remote access

Reference documentation: External Services Configuration - MetaDefender Storage Security

Step 2 — Configure MDSS to Use External Services

On each MDSS node, update the /etc/mdss/customer.env file:

Step 3 — Disable Bundled Services

Since external services are used, disable the built-in services:

DISABLED_SERVICES=postgres,rabbitmq,redis

This ensures each MDSS node does not start local instances.

Step 4 — Start MDSS Nodes (Recommended Approach)

To ensure stable initialization:

1. Start only one MDSS node first

2. Verify all services are running properly

3. Perform a test scan (e.g., upload a sample file)

4. Once validated, start additional nodes using the same configuration

Step 5 — (Optional) Load Balancer

A load balancer is optional but recommended:

• Provides high availability for Web UI/API via a single endpoint

• Should include health checks (e.g., port 443)

Note: Not required for scanning, as workload distribution is handled via RabbitMQ.

Step 6 — (Optional) Automate Active-Passive Failover

If your requirement is failover rather than parallel processing, a reference script is available that monitors the active node and triggers a scan on the passive node once the active one stops responding:

OPSWAT/mdss-active-passive-failover

Configuration is done entirely through PASSIVE_MODE_* environment variables (active and passive URLs and ports, API key, storage ID, workflow ID, check interval and failure threshold). The repository README documents the prerequisites, every variable and how to run the script as a service.

How It Works

• File events (e.g., RTP) are published to the shared RabbitMQ queue

• The first available MDSS node processes the request

• All nodes share the same PostgreSQL database, ensuring consistent state and no duplicate scanning