What are the performance differences between DNS load Balancing and reverse proxy?

The main performance differences between DNS load balancing and reverse proxy are as follows:

Response speed and latency:

DNS load balancing: Since the results of DNS resolution are usually cached on the local DNS server or client, there may be some delay, especially when the DNS record is updated, the caching may cause users to still be directed to the old server address. This delay can affect the user experience.
Reverse proxy: Requests are sent directly to the reverse proxy server, which then forwards them to the back-end server, typically with lower latency and faster response times because there is no need to wait for DNS resolution.
Granularity and flexibility of load balancing:

DNS load balancing: coarse-grained, based on domain names and IP addresses, traffic cannot be intelligently allocated based on server loads or request content.
Reverse proxy: The reverse proxy can control load balancing policies in a more detailed manner, for example, intelligent allocation based on request content, URL, and header information to provide more flexible load balancing capabilities.
Health check and Failover:

DNS load balancing: Real-time health checks are not supported, and if a backend server fails, DNS resolution may still send requests to an unavailable server.
Reverse proxy: Performs health check, monitors the status of back-end servers in real time, and quickly transfers traffic to a healthy server when the server is unavailable, improving system availability and reliability.
Security and hiding back-end servers:

DNS load balancing: The IP address of the back-end server cannot be hidden, and the client can communicate with the back-end server directly.
Reverse proxy: The real IP address of the back-end server can be hidden, which enhances system security, because the client can only see the reverse proxy server.
Scalability and management:

DNS load balancing: Poor scalability, control in the domain name service provider, can not do more customized functions and extended features based on service characteristics.
Reverse proxy: Has better scalability, can add or reduce back-end servers as needed, and can be customized to suit different business needs.
Cache capability:

DNS load balancing: does not have the caching capability and cannot cache static content to improve response speed.
Reverse proxy: Can cache static content, reduce the direct access to the back-end server, improve the response speed and reduce the burden on the back-end server.
To sum up, DNS load balancing and reverse proxy are significantly different in performance, and reverse proxy is generally superior to DNS load balancing in terms of response speed, load balancing flexibility, health check, security, scalability, and caching capabilities.

What are the performance differences between DNS load Balancing and reverse proxy?

Click to expand...

DNS load balancing typically relies on distributing traffic based on DNS queries, so it’s more “hands-off” once the user’s device or ISP caches the DNS record. The upside is it’s generally simpler and adds minimal overhead, but it can take time for any changes to propagate due to DNS caching. Reverse proxies, on the other hand, directly handle incoming requests in real-time, making more dynamic routing decisions based on server load or health. They also let you implement caching, compression, or security measures. However, since they operate at the application layer, they add a bit more processing overhead. In practice, DNS load balancing is great for geographical distribution or a basic “round-robin” approach, while reverse proxies offer greater flexibility and performance tuning for complex sites or applications.