How to Reduce the High Memory Usage on the SQL Server Used by MetaDefender MFT?

Summary

When MetaDefender Managed File Transfer (MFT) is configured to use an external Microsoft SQL Server, administrators may observe high memory usage on the SQL Server machine. This behavior is expected and is related to SQL Server’s built-in memory management and caching mechanisms.
However, if SQL Server consumes too much memory, it may reduce system responsiveness, so setting a maximum memory limit for SQL Server would resolve the issue.

Issue

The SQL Server connected to MetaDefender MFT shows high RAM utilization, and the server may become slow or unresponsive. Symptoms can include:

• Slow MFT application responses when performing SQL queries

• Delayed backups, monitoring operations, or scheduled tasks

• High page file usage (disk swapping)

• General OS sluggishness on the SQL Server host

Cause

This is not a defect in MetaDefender MFT.
The behavior is caused by SQL Server’s intentional memory caching strategy.

SQL Server is designed to use as much memory as possible to cache:

• Data pages

• Execution plans

• Indexes

This design leads to SQL Server:

• Allocating RAM up to the available system limit

• Holding onto memory even when the workload decreases

• Not automatically releasing memory unless OS memory pressure occurs or a hard memory cap is set

Because SQL Server aggressively caches, it may starve the operating system or other applications, causing performance issues.

Resolution

Configure SQL Server’s Maximum Server Memory setting to ensure the operating system and other services retain sufficient RAM.

Recommended Rule

Leave at least 4 GB (or more, depending on the server role) for the OS and background services.

Example

For a SQL Server host with 20 GB RAM:

• Required for OS + background services: ~4 GB

• Recommended SQL Server max memory: 16 GB

This prevents SQL Server from consuming all available RAM and ensures stable system performance.

How to Set the Maximum Memory Limit in SQL Server

1. Open SQL Server Management Studio (SSMS)

2. Connect to your SQL Server instance

3. Right-click the server name → Properties

4. Navigate to the Memory page

5. Under Server Memory Options, set:

   • Maximum server memory (in MB) → enter the desired limit (e.g., 16000 MB for 16 GB)

6. Click OK to apply the new memory configuration

The change takes effect immediately and does not require a SQL Server restart.

Additional Notes

• This configuration is safe and recommended in most production environments.

• You may need to adjust values based on:

  • Total server RAM

  • Number of instances

  • Other applications on the server

• Monitoring tools such as Task Manager may still show SQL Server holding allocated memory, but it will no longer grow beyond the configured limit.