Amazon SageMaker is a fully managed machine learning service that enables data scientists and developers to build, train, and deploy ML models at scale. While SageMaker simplifies many aspects of the ML workflow, proper network configuration is critical for security, compliance, and performance. This article explores best practices for networking in AWS SageMaker environments.
Understanding SageMaker Network Architecture
SageMaker resources can operate in two modes: internet-facing or VPC-isolated. Understanding these modes is fundamental to implementing proper network security.
Internet-Facing vs. VPC Mode
By default, SageMaker notebook instances, training jobs, and endpoints are created with direct internet access. While convenient for getting started, this approach may not meet security requirements for production workloads. VPC mode places SageMaker resources within your Virtual Private Cloud, giving you complete control over network access.
VPC Configuration Best Practices
Use Private Subnets
Always deploy SageMaker resources in private subnets rather than public ones. Private subnets prevent direct internet access to your ML infrastructure, reducing the attack surface significantly.
Creating a SageMaker notebook instance in a private subnet
Implement Multiple Availability Zones
For production workloads, especially SageMaker endpoints serving real-time inference, distribute resources across multiple Availability Zones (AZs). This ensures high availability and fault tolerance.
Network Isolation for Training Jobs
SageMaker training jobs should run in network isolation mode when dealing with sensitive data. This prevents the training container from making outbound network calls.
Enabling network isolation for SageMaker training jobs
Security Groups and NACLs
Principle of Least Privilege
Configure security groups with the minimum required permissions. For SageMaker notebook instances, typically only HTTPS (port 443) needs to be allowed inbound for Jupyter access through the AWS console.
Inbound Rules:
- Type: HTTPS
- Protocol: TCP
- Port: 443
- Source: Your VPC CIDR or specific IP ranges
Outbound Rules:
- Allow necessary AWS service endpoints
- Block all other traffic by default
Separate Security Groups by Function
Create distinct security groups for different SageMaker components:
Security Group Type
Purpose
Notebook Security Group
For development and experimentation
Training Security Group
For training jobs
Endpoint Security Group
For model serving
Data Source Security Group
For databases and data storage
This separation enables fine-grained control and simplifies troubleshooting.
Use Network ACLs as a Second Layer
While security groups provide instance-level security, Network ACLs (NACLs) offer subnet-level protection. Implement NACLs as an additional defense layer, especially for subnets hosting production endpoints.
VPC Endpoints for AWS Services
Why VPC Endpoints Matter
VPC endpoints allow SageMaker resources to communicate with AWS services without traversing the public internet. This improves security, reduces latency, and can lower data transfer costs.
resource"aws_vpc""main"{cidr_block="10.0.0.0/16"enable_dns_support=trueenable_dns_hostnames=true}# Or modify existing VPC attributesdata"aws_vpc""existing"{id="vpc-xxxxx"}resource"aws_vpc_attribute""enable_dns_support"{vpc_id=data.aws_vpc.existing.idenable_dns_support=true}resource"aws_vpc_attribute""enable_dns_hostnames"{vpc_id=data.aws_vpc.existing.idenable_dns_hostnames=true}
importpulumi_awsasawsvpc=aws.ec2.Vpc("main",cidr_block="10.0.0.0/16",enable_dns_support=True,enable_dns_hostnames=True)# Or modify existing VPCexisting_vpc=aws.ec2.get_vpc(id="vpc-xxxxx")# Note: Pulumi manages these through VPC resource properties
import*asec2from'aws-cdk-lib/aws-ec2';constvpc=newec2.Vpc(this,'MainVPC',{maxAzs:2,// DNS support and hostnames are enabled by default in CDK});// For existing VPC, these attributes should be set on the VPC construct// CDK VPCs have enableDnsHostnames and enableDnsSupport set to true by default
Enabling DNS resolution and hostnames in VPC
Private Hosted Zones
For custom endpoints or when integrating with on-premises resources, use Route 53 private hosted zones to manage DNS resolution within your VPC.
Data Encryption in Transit
Enforce TLS for All Communications
Always use TLS encryption for data in transit. SageMaker supports TLS 1.2 and higher for all API calls and notebook access.
VPN or Direct Connect for Hybrid Environments
If your ML workflow involves on-premises data sources, establish secure connectivity using AWS VPN or Direct Connect rather than transmitting data over the public internet.
Monitoring and Logging
VPC Flow Logs
Enable VPC Flow Logs to capture network traffic metadata. This is invaluable for security analysis, compliance auditing, and troubleshooting network issues.
importpulumi_awsasawsimportpulumilog_group=aws.cloudwatch.LogGroup("vpc-flow-logs",name="/aws/vpc/flowlogs",retention_in_days=7)# Create IAM role for VPC Flow Logsflow_logs_role=aws.iam.Role("vpc-flow-logs-role",assume_role_policy=pulumi.Output.json_dumps({"Version":"2012-10-17","Statement":[{"Action":"sts:AssumeRole","Effect":"Allow","Principal":{"Service":"vpc-flow-logs.amazonaws.com"}}]}))# Attach policy to roleflow_logs_policy=aws.iam.RolePolicy("vpc-flow-logs-policy",role=flow_logs_role.id,policy=pulumi.Output.json_dumps({"Version":"2012-10-17","Statement":[{"Action":["logs:CreateLogGroup","logs:CreateLogStream","logs:PutLogEvents","logs:DescribeLogGroups","logs:DescribeLogStreams"],"Effect":"Allow","Resource":"*"}]}))# Create VPC Flow Logflow_log=aws.ec2.FlowLog("vpc-flow-log",vpc_id="vpc-xxxxx",traffic_type="ALL",log_destination_type="cloud-watch-logs",log_destination=log_group.arn,iam_role_arn=flow_logs_role.arn)
import*asec2from'aws-cdk-lib/aws-ec2';import*aslogsfrom'aws-cdk-lib/aws-logs';import*asiamfrom'aws-cdk-lib/aws-iam';constlogGroup=newlogs.LogGroup(this,'VPCFlowLogs',{logGroupName:'/aws/vpc/flowlogs',retention:logs.RetentionDays.ONE_WEEK});// Create VPC Flow Log (IAM role created automatically)constvpc=ec2.Vpc.fromLookup(this,'VPC',{vpcId:'vpc-xxxxx'});vpc.addFlowLog('FlowLog',{destination:ec2.FlowLogDestination.toCloudWatchLogs(logGroup),trafficType:ec2.FlowLogTrafficType.ALL});
Implement AWS Config rules to ensure network configurations remain compliant:
Verify SageMaker notebooks are in VPCs
Confirm network isolation is enabled for training jobs
Validate security group configurations
Cost Optimization
Use S3 Gateway Endpoints
S3 gateway endpoints are free and eliminate data transfer charges for S3 access within the same region. This can result in significant cost savings for data-intensive ML workloads.
Right-Size VPC Endpoints
Interface endpoints incur hourly charges and data processing fees. Only create endpoints for services you actually use, and share endpoints across workloads when possible.
NAT Gateway Optimization
If you need internet access for certain operations (like installing packages), use NAT Gateways judiciously:
Share NAT Gateways across multiple private subnets
Consider NAT instances for dev/test environments
Use VPC endpoints instead of NAT for AWS service access
Compliance and Governance
Network Segmentation
Segregate different environments (dev, staging, production) into separate VPCs or subnets. This prevents cross-contamination and simplifies compliance controls.
Tagging Strategy
Implement a comprehensive tagging strategy for all network resources:
When integrating with third-party ML tools or data sources, use AWS PrivateLink to maintain private connectivity without exposing your VPC to the internet.
Troubleshooting Common Network Issues
Connection Timeouts
If SageMaker resources can't reach required services:
Verify security group rules allow outbound traffic
Confirm route tables direct traffic correctly
Check VPC endpoint configuration and policies
Validate IAM role permissions
DNS Resolution Failures
If DNS isn't resolving for VPC endpoints:
Ensure DNS resolution is enabled in the VPC
Verify private DNS is enabled for interface endpoints
Check DHCP options sets are correct
Performance Issues
If experiencing slow data transfer or inference latency:
Review VPC endpoint placement across AZs
Check for cross-AZ data transfer
Validate network bandwidth isn't saturated
Consider using Enhanced Networking for EC2-based components
Example: Secure Production Architecture
Here's a complete example of a secure SageMaker architecture:
importboto3fromsagemakerimportSession,get_execution_roleec2=boto3.client('ec2')sagemaker_client=boto3.client('sagemaker')# VPC Configurationvpc_id='vpc-xxxxx'private_subnet_1='subnet-aaaaa'# us-east-1aprivate_subnet_2='subnet-bbbbb'# us-east-1b# Security Groupstraining_sg='sg-training'endpoint_sg='sg-endpoint'# Create VPC Endpointsendpoints=['com.amazonaws.us-east-1.sagemaker.api','com.amazonaws.us-east-1.sagemaker.runtime','com.amazonaws.us-east-1.ecr.api','com.amazonaws.us-east-1.ecr.dkr','com.amazonaws.us-east-1.s3','com.amazonaws.us-east-1.logs']# Training job with network isolationsagemaker=Session()role=get_execution_role()fromsagemaker.estimatorimportEstimatorestimator=Estimator(image_uri='my-secure-training-image',role=role,instance_count=2,instance_type='ml.p3.2xlarge',volume_size=100,subnets=[private_subnet_1,private_subnet_2],security_group_ids=[training_sg],enable_network_isolation=True,encrypt_inter_container_traffic=True)# Deploy model with VPC configurationpredictor=estimator.deploy(initial_instance_count=2,instance_type='ml.m5.xlarge',endpoint_name='secure-ml-endpoint',vpc_config={'Subnets':[private_subnet_1,private_subnet_2],'SecurityGroupIds':[endpoint_sg]})
Proper networking configuration is essential for secure, compliant, and performant SageMaker deployments. By following these best practices—using private subnets, implementing VPC endpoints, configuring security groups correctly, and enabling comprehensive monitoring—you can build ML infrastructure that meets enterprise security requirements while maintaining the agility needed for rapid model development and deployment.
Remember that network architecture should evolve with your ML operations maturity. Start with basic VPC isolation for development, then progressively add more sophisticated controls as you move toward production. Regular security audits and configuration reviews ensure your network remains secure as your ML workloads grow and change.