Amazon AWS application ELB Service discovery

Release version: Washingtondc

Updated February 1, 2024

2 minutes to read

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Summary of Amazon AWS Application ELB Service Discovery

The Amazon AWS application ELB Service discovery pattern in ServiceNow ITOM Visibility enables customers to visualize all load balancers in their environment through a comprehensive map. This pattern leverages Elastic Load Balancing (ELB) to efficiently distribute incoming application traffic across multiple targets and supports top-down discovery for enhanced visibility.

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Key Features

Supports ultra-high performance, TLS offloading at scale, and centralized certificate deployment.
Compatible with UDP and static IP addresses for applications.
Entry point for top-down discovery is the HTTP(s) Endpoint, with outgoing relations to Amazon EC2 instances.
Utilizes Amazon Commercial Cloud Services (C2S) for discovery and cloud governance.
Requires ServiceNow Kingston or later releases for implementation.

Key Outcomes

To effectively use this discovery pattern, ensure the following:

Run a horizontal discovery using Cloud API (CAPI).
Create application services for each load balancer once data is stored in the Configuration Management Database (CMDB).
Set read-only permissions for specified REST APIs necessary for data retrieval.
Download relevant Discovery and Service Mapping Patterns from the ServiceNow Store for installation and configuration guidance.
Use the Cloud Discovery patterns spreadsheet to manage user permissions and access patterns effectively.

Testing of AWS REST APIs can be conducted using platforms like Postman for validation purposes. Regular updates to discovery patterns are released quarterly, so checking for new versions is advisable.

Discovery uses the Amazon AWS application ELB Service discovery pattern to show all load balancers in your environment in a map.

Elastic Load Balancing (ELB) automatically distributes incoming application traffic across multiple targets.

The Amazon AWS application ELB Service discovery pattern supports top-down discovery. This pattern discovers all load balancers with these characteristics:

Use ultra-high performance, TLS offloading at scale, and centralized certificate deployment
Support UDP and static IP addresses for your application

For top-down discovery, the entry point is HTTP(s) Endpoint. Outgoing relations are to Amazon EC2 instances.

The ServiceNow AI Platform supports Amazon Commercial Cloud Services (C2S) for discovery and cloud governance. C2S is the government program that brings AWS into the Intelligence Community.

You can use this pattern on the ServiceNow platform using Kingston or later releases.

Visit the ServiceNow Store website to view all the available apps and for information about submitting requests to the store. For cumulative release notes information for all released apps, see the ServiceNow Store version history release notes.

Prerequisites

Run a horizontal discovery, using Cloud API (CAPI). This is necessary because this discovery pattern supports top-down discovery only. For Cloud Discovery, you can run the horizontal discovery as usual.
When the load balancers data has been stored in the Configuration Management Database (CMDB), create an application service for each load balancer.
Set read-only permissions for these REST APIs:
- https://elasticloadbalancing.<REGION>.amazonaws.com/?Action=DescribeLoadBalancers&LoadBalancerArns.member.1=<LB_ARN>&Version=2015-12-01
- https://elasticloadbalancing.<REGION>.amazonaws.com/?Action=DescribeLoadBalancers&Version=2015-12-01
- https://elasticloadbalancing.<REGION>.amazonaws.com/?Action=DescribeListeners&LoadBalancerArn=<LB_ARN>&Version=2015-12-01
- https://elasticloadbalancing.<REGION>.amazonaws.com/?Action=DescribeRules&ListenerArn=<LISTENER_ARN>&Version=2015-12-01
- https://elasticloadbalancing.<REGION>.amazonaws.com/?Action=DescribeTargetHealth&TargetGroupArn=<TARGET_GROUP_ARN>&Version=2015-12-01
- https://ec2.<REGION>.amazonaws.com/?Action=DescribeInstances&Version=2016-11-15&Filter.1.Name=instance-state-name&Filter.1.Value=running&Filter.2.Name=instance-id&Filter.2.Value=<INSTANCE_ID>
For Cloud Discovery, download the Discovery and Service Mapping Patterns from the ServiceNow Store.
When installing the MID Server, ensure that the host machine meets or exceeds the MID Server system requirements published on the ServiceNow documentation site.

Verify the REST API Permissions

Download the Cloud Discovery patterns spreadsheet so you can grant user permissions required for running the Discovery patterns. In addition to permissions, the spreadsheet also includes useful information such as pattern names, types, CI Classes, and links to vendor documentation. New patterns are available quarterly, so check periodically to be sure you have the latest version of the spreadsheet.

Note:

You can test the AWS REST APIs using Postman API platform. For more information, see the How to test AWS REST API using POSTMAN [KB0782183] article in the Now Support Knowledge Base.

Data collected by Discovery during horizontal discovery

The discovered data includes the following tables and fields.


Table and field	Description
Load Balancer Services [cmdb_ci_lb_service]
Fully qualified domain name [fqdn]	Fully Qualified Domain Name (FQDN) of the load balancer. The DNS name.
Name [name]	Name of the load balancer, in the following format: <LB name>:<LB port>.
Serial Number [serial_number]	Serial number of the load balancer, in the following format: ##Object_ID=<LB_ARN>.
Port [port]	Port of the load balancer.
Object ID [object_id]	Unique identifier of the load balancer.
IP Address [ip_address]	IP address of the FQDN.