As serverless architectures become increasingly popular, businesses are faced with new challenges in managing their costs and preventing security threats such as denial of wallet attacks. A denial of wallet attack occurs when an attacker abuses an application’s functionality to cause excessive usage of serverless resources, resulting in unexpected bills for the victim. In this post, we will explore several strategies that businesses can use to mitigate the risk of a denial of wallet attack and optimize their serverless costs. We will discuss rate limiting, setting up a budget and alerts, using serverless cost optimization tools, caching, and other best practices that businesses can implement to protect their serverless infrastructure and ensure the long-term sustainability of their applications.
1. Rate Limiting
Rate limiting requests is an effective way to prevent a denial of wallet attack. By limiting the number of requests that can be made to your serverless infrastructure, you can prevent your costs from spiraling out of control due to excessive traffic.
One way to implement rate limiting is by using a service like AWS API Gateway. AWS API Gateway allows you to set a limit on the number of requests that can be made to your API within a specified time period. This can help prevent excessive traffic from overwhelming your infrastructure and racking up costs.
Another way to implement rate limiting is by using a custom code-based solution. For example, you could write a Lambda function that monitors the number of requests being made to your infrastructure and throttles them if they exceed a certain limit. This can be a more flexible solution than using a service like AWS API Gateway, as you can customize the behavior of the throttling based on your specific needs.
Regardless of the approach you take, it’s important to set reasonable limits on the number of requests that can be made to your infrastructure. This will help ensure that your costs remain manageable, even in the event of unexpected traffic spikes.
Rate Limiting Vectors
There are several vectors on which you can implement rate limiting to prevent a denial of wallet attack. Some of the commonly used vectors for rate limiting include:
- IP Address: By limiting the number of requests from a particular IP address within a specified time period, you can prevent a single user or bot from overwhelming your infrastructure.
- API Keys: If you provide API keys to your customers, you can use them to implement rate limiting. By limiting the number of requests per API key within a specified time period, you can prevent a single user or application from making too many requests.
- User Accounts: If you require users to create accounts to access your infrastructure, you can implement rate limiting on a per-account basis. This allows you to limit the number of requests that each user can make within a specified time period.
- Geolocation: If your infrastructure serves a specific geographic area, you can implement rate limiting based on the location of the request. By limiting the number of requests from certain regions or countries, you can prevent excessive traffic from outside your target audience.
- Request Type: You can also implement rate limiting based on the type of request being made. For example, you may want to limit the number of requests for certain resource-intensive operations, such as file uploads or downloads.
It’s important to choose the appropriate vector for rate limiting based on the specific needs of your infrastructure. By implementing rate limiting on the appropriate vectors, you can prevent excessive traffic and keep your costs under control.
2. Set up Budget and Alerts
Setting up a budget and alerts is another effective way to mitigate the risk of a denial of wallet attack. By monitoring your spending and setting up alerts when you approach your budget limits, you can stay on top of your serverless costs and avoid unexpected bills.
To set up a budget and alerts, you can use the cost management tools provided by your cloud provider, such as AWS Cost Explorer. These tools allow you to set up a budget for your serverless infrastructure and receive alerts when you approach your budget limits. You can also configure alerts for specific types of spending, such as data transfer or storage.
In addition to using cloud provider tools, you can also use third-party cost management tools to monitor your serverless costs. For example, CloudCheckr and Cloudability are two popular cost management tools that can help you monitor your serverless spending and identify areas where you can optimize your costs.
When setting up your budget and alerts, it’s important to choose appropriate spending limits that reflect the needs of your infrastructure. You should also consider setting up alerts for unexpected spikes in traffic or spending, which can be an indication of a potential denial of wallet attack.
By monitoring your serverless spending and setting up appropriate alerts, you can stay in control of your costs and prevent unexpected bills. This can help you avoid the financial impact of a denial of wallet attack and ensure the long-term sustainability of your serverless infrastructure.
3. Use Serverless Cost Optimization Tools
In addition to implementing rate limiting and setting up a budget and alerts, businesses can also use serverless cost optimization tools to further optimize their serverless costs.
There are several third-party tools available that can help businesses optimize their serverless infrastructure, including:
- Lumigo: Lumigo is a serverless monitoring and troubleshooting tool that helps businesses optimize their AWS Lambda costs. It provides real-time visibility into Lambda performance and costs and identifies areas where businesses can optimize their Lambda functions.
- Thundra: Thundra is another serverless monitoring tool that provides deep insights into the performance and cost of serverless applications. It helps businesses identify performance bottlenecks and cost-saving opportunities.
- Epsagon: Epsagon is a distributed tracing and monitoring platform for serverless architectures. It helps businesses identify and troubleshoot issues in real-time, and provides insights into serverless costs and usage.
- Dashbird: Dashbird is a monitoring and error reporting tool for serverless architectures. It provides real-time insights into the performance and costs of serverless applications and helps businesses optimize their serverless costs.
These tools can help businesses identify areas where they can optimize their serverless costs, such as inefficient code, excessive memory usage, and unnecessary resource allocation. By optimizing their serverless infrastructure, businesses can reduce their costs and prevent unexpected bills from a denial of wallet attack.
4. Use Caching
Caching is another effective way to shield against denial of wallet attacks by reducing the number of requests made to your serverless infrastructure. By caching frequently accessed data, you can serve requests more quickly and reduce the load on your serverless infrastructure.
There are several caching strategies that businesses can use to optimize their serverless infrastructure and prevent a denial of wallet attack, including:
- Content Delivery Networks (CDNs): CDNs are a type of caching service that distribute content across a network of servers. By caching frequently accessed content on these servers, CDNs can reduce the load on your serverless infrastructure and serve content more quickly to end-users.
- Edge Caching: Edge caching is a type of caching that is performed at the edge of a network, closer to the end-user. By caching content closer to the end-user, edge caching can reduce latency and improve the user experience.
- In-Memory Caching: In-memory caching is a type of caching that stores frequently accessed data in memory, rather than on disk. This can improve the performance of serverless applications by reducing the amount of time it takes to access data.
- Browser Caching: Browser caching is a type of caching that stores frequently accessed data on the end-user’s browser. By caching content on the browser, businesses can reduce the number of requests made to their serverless infrastructure and improve the user experience.
By implementing caching strategies, businesses can shield their serverless infrastructure from a denial of wallet attack by reducing the number of requests made to their infrastructure. This can also improve the performance of serverless applications and reduce the risk of unexpected bills due to excessive usage.
In summary, businesses can shield their serverless infrastructure from a denial of wallet attack by implementing caching strategies such as CDNs, edge caching, in-memory caching, and browser caching. By reducing the load on their serverless infrastructure, businesses can improve the performance of their applications and reduce the risk of unexpected bills from a denial of wallet attack.
