48 lines
2.4 KiB
Markdown
48 lines
2.4 KiB
Markdown
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noatcards = True
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isdraft = False
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# Reverse proxy (web server)
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## Reverse proxy (web server) introduction
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[Source: Wikipedia](https://commons.wikimedia.org/wiki/File:Proxy_concept_en.svg)
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A reverse proxy is a web server that centralizes internal services and provides unified interfaces to the public. Requests from clients are forwarded to a server that can fulfill it before the reverse proxy returns the server's response to the client.
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## Reverse Proxy benefit
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Additional benefits include:
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- Increased security - Hide information about backend servers, blacklist IPs, limit number of connections per client
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- Increased scalability and flexibility - Clients only see the reverse proxy's IP, allowing you to scale servers or change their configuration
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- SSL termination - Decrypt incoming requests and encrypt server responses so backend servers do not have to perform these potentially expensive operations
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- Removes the need to install [X.509 certificates](https://en.wikipedia.org/wiki/X.509) on each server
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- Compression - Compress server responses
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- Caching - Return the response for cached requests
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- Static content - Serve static content directly
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- HTML/CSS/JS
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- Photos
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- Videos
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- Etc
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## Load balancer vs reverse proxy
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- Deploying a load balancer is useful when you have multiple servers. Often, load balancers route traffic to a set of servers serving the same function.
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- Reverse proxies can be useful even with just one web server or application server, opening up the benefits described in the previous section.
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- Solutions such as NGINX and HAProxy can support both layer 7 reverse proxying and load balancing.
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## Disadvantage(s) : reverse proxy
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- Introducing a reverse proxy results in increased complexity.
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- A single reverse proxy is a single point of failure, configuring multiple reverse proxies (ie a [failover](https://en.wikipedia.org/wiki/Failover)) further increases complexity.
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## Source(s) and further reading
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- [Reverse proxy vs load balancer](https://www.nginx.com/resources/glossary/reverse-proxy-vs-load-balancer/)
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- [NGINX architecture](https://www.nginx.com/blog/inside-nginx-how-we-designed-for-performance-scale/)
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- [HAProxy architecture guide](http://www.haproxy.org/download/1.2/doc/architecture.txt)
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- [Wikipedia](https://en.wikipedia.org/wiki/Reverse_proxy)
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