Multiple Model Endpoint Routing with AWS Load Balancer Target Groups
PythonTo facilitate multiple model endpoint routing using AWS Load Balancer Target Groups, we will set up resources to direct traffic to different endpoints based on specified routing rules. Here's how this can be achieved using Pulumi and AWS:
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Load Balancer (ALB): The Application Load Balancer will receive incoming traffic and distribute it across multiple target groups based on the defined listener rules.
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Target Groups: Each model endpoint will be associated with its own target group. A target group allows you to route requests to one or more registered targets, such as EC2 instances, containers, or IP addresses.
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Listener Rules: We will define rules on the load balancer's listener to check for conditions such as path patterns or host headers and forward the requests to the corresponding target group based on these conditions.
Here's a Pulumi program in Python that shows how you can define these resources. For simplicity, we assume that the EC2 instances or containers serving the model endpoints are already running.
import pulumi import pulumi_aws as aws # Create a new VPC if not using the default one. vpc = aws.ec2.Vpc("vpc") # Create an Internet-facing Application Load Balancer. load_balancer = aws.lb.LoadBalancer("loadBalancer", subnets=[], # Specify the subnets for the Load Balancer. load_balancer_type="application", security_groups=[], # Attach appropriate security groups. enable_http2=True, ) # Create a target group for Model A Endpoint. target_group_model_a = aws.lb.TargetGroup("targetGroupModelA", port=80, protocol="HTTP", vpc_id=vpc.id, health_check={ "path": "/health", # Path for the health check endpoint. "interval": 30, }, ) # Create a target group for Model B Endpoint. target_group_model_b = aws.lb.TargetGroup("targetGroupModelB", port=80, protocol="HTTP", vpc_id=vpc.id, health_check={ "path": "/health", "interval": 30, }, ) # Assume you have a listener set up on the load balancer. listener = aws.lb.Listener("listener", load_balancer_arn=load_balancer.arn, port=80, protocol="HTTP", ) # Create a listener rule to route traffic to Model A Endpoint based on the path. listener_rule_model_a = aws.lb.ListenerRule("listenerRuleModelA", actions=[{ "type": "forward", "target_group_arn": target_group_model_a.arn, }], conditions=[{ "path_pattern": { "values": ["/model-a*"], }, }], listener_arn=listener.arn, priority=10, ) # Create a listener rule to route traffic to Model B Endpoint based on the path. listener_rule_model_b = aws.lb.ListenerRule("listenerRuleModelB", actions=[{ "type": "forward", "target_group_arn": target_group_model_b.arn, }], conditions=[{ "path_pattern": { "values": ["/model-b*"], }, }], listener_arn=listener.arn, priority=20, ) # Export the Load Balancer DNS name to access the model endpoints. pulumi.export("load_balancer_dns_name", load_balancer.dns_name)
In this program:
-
A
LoadBalancer
resource is created to handle incoming requests. We specify that it's an application load balancer withload_balancer_type="application"
, and it is internet-facing by default. -
Two
TargetGroup
resources represent groups for each of the model's endpoints. You need to provide theprotocol
,port
,vpc_id
, andhealth_check
configurations. -
A
Listener
is attached to the load balancer to listen to the HTTP traffic on port 80. -
Two
ListenerRule
resources are defined, one for Model A withpath_pattern
: "/model-a*" and one for Model B withpath_pattern
: "/model-b*". These rules forward traffic to the respective target groups based on the URL path requested.
Please replace placeholders for
subnets
andsecurity_groups
with actual values from your setup, and modify thepath
in thehealth_check
configuration to point to the correct path for health checking each of the endpoints.The
priority
value in the listener rules is used to determine the order of rule evaluation when requests are received; lower numbers have higher precedence.Finally, we export the DNS name of the load balancer, which you can use to access your model endpoints from the internet.
This setup will route traffic to
http://<load_balancer_dns_name>/model-a
to the Model A endpoint and traffic tohttp://<load_balancer_dns_name>/model-b
to the Model B endpoint. To view the Load Balancer DNS name after deployment, you can runpulumi stack output load_balancer_dns_name
.Ensure that the target EC2 instances or containers are properly registered with their respective target groups and are configured to respond to the health check path you've specified.
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