Amazon OpenSearch Service makes it easy for you to perform interactive log analytics, real-time application monitoring, website search, and more. Amazon OpenSearch is an open source, distributed search and analytics suite. Amazon OpenSearch Service offers the latest versions of OpenSearch, support for 19 versions of Elasticsearch (1.5 to 7.10 versions), as well as visualization capabilities powered by OpenSearch Dashboards and Kibana (1.5 to 7.10 versions). Amazon OpenSearch Service currently has tens of thousands of active customers with hundreds of thousands of clusters under management processing trillions of requests per month.
To meet the needs of customers who want simplicity in their network setup with the Amazon OpenSearch Service, you can now use Amazon OpenSearch Service-managed virtual private cloud (VPC) endpoints (powered by AWS PrivateLink) to connect to your applications using Amazon OpenSearch Service domains launched in Amazon Virtual Private Cloud (VPC). With Amazon OpenSearch Service-managed VPC endpoints, you can privately access your Amazon OpenSearch Service domain from multiple VPCs in your account or other AWS accounts based on your application needs without configuring other services features such as VPC peering, AWS Transit Gateway (TGW), or other more complex network routing strategies that place operational burden on your support and engineering teams.
The feature is built using AWS PrivateLink. AWS PrivateLink provides private connectivity between VPCs, supported AWS services, and your on-premises networks without exposing your traffic to the public internet. It provides you with the means to connect multiple application deployments effortlessly to your Amazon OpenSearch Service domains.
This post introduces Amazon OpenSearch Service-managed VPC endpoints that build on top of AWS PrivateLink and shows how you can access a private Amazon OpenSearch Service from one or more VPCs hosted in the same account, or even VPCs hosted in other AWS accounts using AWS PrivateLink managed by Amazon OpenSearch Service.
Amazon OpenSearch Service managed VPC endpoints
Before the launch of Amazon OpenSearch Service managed VPC endpoints, if you needed to gain access to your domain outside of your VPC, you had three options:
- Use VPC peering to connect your VPC with other VPCs
- Use AWS Transit Gateway to connect your VPC with other VPCs
- Create your own implementation of an AWS PrivateLink setup
The first two options require you to setup your VPCs so that the Classless Inter-Domain Routing (CIDR) block ranges don’t overlap. If they did, then your options are more complicated. The third option, create your own implementation of AWS PrivateLink, involve configuring a network load balancer (NLB) and associating a target group with the NLB as one of the steps in the setup. The architecture discussed in this post, demonstrates these additional layers of complexity.
With Amazon OpenSearch Service managed VPC endpoints (i.e., powered by AWS PrivateLink), these complex setups and processes are no longer needed!
You can access your Amazon OpenSearch Service private domain as if it were deployed in all the VPCs that you want to connect to your domain. If you need private connectivity from your on-premises hybrid deployments, then AWS PrivateLink helps you bring access from your Amazon OpenSearch Service domain to your data centers with minimal effort.
By using AWS PrivateLink with Amazon OpenSearch Service, you can realize the following benefits:
- You simplify your network architecture between hybrid, multi-VPC, and multi account solutions
- You address a multitude of compliance concerns by better controlling the traffic that moves between your solutions and Amazon OpenSearch Service domains
Shared search cluster for multiple development teams
Imagine that your company hosts a service as a software (SaaS) application that provides a search application programming interface (API) for the healthcare industry. Each team works on a different function of the API. The development teams API team 1 and API team 2 are in two different AWS accounts and each has their own VPCs within these accounts. Another team (data refinement team) works on the ingestion and data refinement to populate the Amazon OpenSearch Service domain hosted in the same account as API team 2 but in different VPC. Each team shares the domain during the development cycles to save costs and foster collaboration on the data modeling.
Solution overview
Self-managed AWS PrivateLink architecture to connect different VPCs
In this scenario prior to Amazon OpenSearch Service manage VPC endpoints (i.e., powered by AWS PrivateLink), you would have to create the following items:
- Deploy an NLB in your VPC
- Create a target group that points to the IP addresses of the Elastic Network Interfaces (ENIs), which the Amazon OpenSearch Service creates in your VPC and is used to launch the Amazon OpenSearch Service
- Create an AWS PrivateLink deployment and reference your newly created NLB
When you implement the NLB, a target group can only reference IP addresses, an Amazon EC2 instance, or an Application Load Balancer (ALB). If you referenced the IP addresses as targets, then you had to build a process that detected the changes in the IP address if the domain changed due to service initiated or self-initiated blue/green deployments. You must maintain yet another complex process to ensure that you always have active ENIs with which to point your target groups or you lose connectivity.
Typically, customers use an AWS Lambda with scheduled events in Amazon CloudWatch. This means that you use the AWS Lambda to detect the current state where the ENIs that provided the IP addresses were marked as active for the description that matched the ENIs your domain creates. You schedule AWS Lambda to wake up within the time to live (TTL) of the Domain Name Service (DNS) settings (typically 60 seconds) and compare the existing IP addresses in the target group with any new ones found when you query all ENIs with a description referencing your domain in the VPC. You then build a new target group with the deltas and you swap the target groups and drop the old one. It’s tricky, it’s complex, and you have to maintain the solution!
With the new simplified networking architecture, your teams go through the following steps.
OpenSearch Service managed VPC endpoints architecture (powered by AWS PrivateLink)
Since the Amazon OpenSearch Service takes care of the infrastructure described previously — but not necessarily on the same implementation — all you really need to concern yourself with is creating the connections using the instructions in our service documentation.
Once you complete the steps in the instructions and remove your own implementation, your architecture is then simplified as seen in the following diagram.
At this point, the development teams (API team 1 and API team 2) can access the Amazon OpenSearch cluster via Amazon OpenSearch Service Managed VPC Endpoint. This option is highly scalable with a simplified network architecture in which you don’t have to worry about managing a NLB, or setting up target groups and the additional resources. If the number of development teams and VPCs grow in the future, you associate the domain with the associated interface VPC endpoint. You can access services in VPCs in same or different accounts, even if there are overlapping CIDR Block IP ranges.
Conclusion
In this post, we walked through the architectural design of accessing Amazon OpenSearch cluster from different VPCs across different accounts using OpenSearch Service-managed VPC endpoint (AWS PrivateLink). Using Transit Gateway, self-managed AWS PrivateLink or VPC peering required complex networking strategies that increased operation burden. With the introduction of VPC endpoints for Amazon OpenSearch Service, the complexity of your solutions is greatly simplified and what’s even better, it’s managed for you!
About the authors
Aish Gunasekar is a Specialist Solutions architect with a focus on Amazon OpenSearch Service. Her passion at AWS is to help customers design highly scalable architectures and help them in their cloud adoption journey. Outside of work, she enjoys hiking and baking.
Kevin Fallis (Kevin Fallis (@AWSCodeWarrior) is an AWS specialist search solutions architect. His passion at AWS is to help customers leverage the correct mix of AWS services to achieve success for their business goals. His after-work activities include family, DIY projects, carpentry, playing drums, and all things music.