HAProxy vs Varnish

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HAProxy

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2.1K
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560
Varnish

12.4K
2.6K
+ 1
370
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HAProxy vs Varnish: What are the differences?

Introduction:

HAProxy and Varnish are both widely used open-source software that serve specific purposes in the web application stack. Although they are both used for optimizing and managing web traffic, there are key differences between HAProxy and Varnish that make them distinct from each other.

  1. Load Balancing vs Caching: The primary purpose of HAProxy is to act as a load balancer, evenly distributing incoming requests across multiple backend servers to ensure high availability and scalability. On the other hand, Varnish is mainly used as a caching reverse proxy, storing and serving static or dynamically-generated content from cache to improve website performance and reduce server load.

  2. Layer 7 vs Layer 4 Load Balancing: HAProxy operates at the application layer (Layer 7) of the Open Systems Interconnection (OSI) model, allowing it to make routing decisions based on HTTP headers, cookies, and other application-specific information. This enables advanced load balancing and routing techniques such as content-based routing. Varnish, however, works at the transport layer (Layer 4) and operates primarily based on IP addresses and port numbers, without inspecting the contents of the application payload.

  3. Request Processing vs Content Serving: HAProxy excels at efficiently processing and forwarding incoming requests to the appropriate backend servers, ensuring the responsiveness and performance of web applications. Varnish, on the other hand, focuses on serving static or cached content directly from memory, reducing the need to access backend servers for frequently accessed data. By serving content directly from cache, Varnish significantly improves response times and reduces the load on backend servers.

  4. SSL Termination: HAProxy has built-in SSL termination capabilities, allowing it to handle secure connections and perform SSL offloading. It can encrypt and decrypt SSL/TLS traffic, reducing the computational burden on backend servers. Varnish, on the other hand, does not offer native SSL termination and usually relies on other components in the architecture, such as a load balancer or a web server, to handle secure connections.

  5. Flexible Configuration vs Domain-Specific Language: HAProxy provides a flexible and powerful configuration language that allows administrators to define complex load balancing, traffic routing, and health-checking rules. This flexibility enables fine-grained control and customization of the load balancing behavior. In contrast, Varnish uses its own domain-specific language (VCL) for configuration, which is optimized for caching and content serving. While VCL offers flexibility in cache management and content manipulation, it requires a learning curve for administrators who are not familiar with VCL.

  6. Community and Ecosystem: HAProxy has a large and active community, with extensive documentation, a rich set of features, and many plugins and integrations. It is widely adopted by organizations of various sizes and has a proven track record in high-performance load balancing. Varnish also has a vibrant community and ecosystem, but it is more focused on caching and content delivery rather than load balancing. Varnish is often used in combination with other software, such as a load balancer, to provide a complete web application delivery solution.

In Summary, HAProxy is a highly versatile and powerful load balancer, whereas Varnish is a caching reverse proxy that excels at serving static and cached content. While HAProxy focuses on load balancing at the application layer and offers SSL termination capabilities, Varnish specializes in caching and content serving. Both have their specific use cases and can be used together to optimize web application performance and availability.

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Pros of HAProxy
Pros of Varnish
  • 131
    Load balancer
  • 102
    High performance
  • 69
    Very fast
  • 58
    Proxying for tcp and http
  • 55
    SSL termination
  • 31
    Open source
  • 27
    Reliable
  • 20
    Free
  • 18
    Well-Documented
  • 12
    Very popular
  • 7
    Runs health checks on backends
  • 7
    Suited for very high traffic web sites
  • 6
    Scalable
  • 5
    Ready to Docker
  • 4
    Powers many world's most visited sites
  • 3
    Simple
  • 2
    Work with NTLM
  • 2
    Ssl offloading
  • 1
    Available as a plugin for OPNsense
  • 104
    High-performance
  • 67
    Very Fast
  • 57
    Very Stable
  • 44
    Very Robust
  • 37
    HTTP reverse proxy
  • 21
    Open Source
  • 18
    Web application accelerator
  • 11
    Easy to config
  • 5
    Widely Used
  • 4
    Great community
  • 2
    Essential software for HTTP

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Cons of HAProxy
Cons of Varnish
  • 6
    Becomes your single point of failure
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    - No public GitHub repository available -

    What is HAProxy?

    HAProxy (High Availability Proxy) is a free, very fast and reliable solution offering high availability, load balancing, and proxying for TCP and HTTP-based applications.

    What is Varnish?

    Varnish Cache is a web application accelerator also known as a caching HTTP reverse proxy. You install it in front of any server that speaks HTTP and configure it to cache the contents. Varnish Cache is really, really fast. It typically speeds up delivery with a factor of 300 - 1000x, depending on your architecture.

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    What companies use HAProxy?
    What companies use Varnish?
    See which teams inside your own company are using HAProxy or Varnish.
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    What tools integrate with HAProxy?
    What tools integrate with Varnish?

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    Blog Posts

    May 6 2020 at 6:34AM

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    What are some alternatives to HAProxy and Varnish?
    NGINX
    nginx [engine x] is an HTTP and reverse proxy server, as well as a mail proxy server, written by Igor Sysoev. According to Netcraft nginx served or proxied 30.46% of the top million busiest sites in Jan 2018.
    Traefik
    A modern HTTP reverse proxy and load balancer that makes deploying microservices easy. Traefik integrates with your existing infrastructure components and configures itself automatically and dynamically.
    Envoy
    Originally built at Lyft, Envoy is a high performance C++ distributed proxy designed for single services and applications, as well as a communication bus and “universal data plane” designed for large microservice “service mesh” architectures.
    Squid
    Squid reduces bandwidth and improves response times by caching and reusing frequently-requested web pages. Squid has extensive access controls and makes a great server accelerator. It runs on most available operating systems, including Windows and is licensed under the GNU GPL.
    Pound
    Pound was developed to enable distributing the load among several Web-servers and to allow for a convenient SSL wrapper for those Web servers that do not offer it natively.
    See all alternatives