#Http request analysis full

For our example, we want to know whether the image is being delivered by the StackPath CDN.

The second column is where you can analyze the cache headers. Here we did not customize the HTTP request but you can do so to detect security problems and further test server performance. In the example below we send a GET request for an image published in an article by Techspot, a StackPath customer. The first column is where you can select a request type and a URL. The ReqBin web app is separated into two columns (see below). While they donвЂ™t perform bulk requests like Request-as-a-Service (RaaS) tools, they master the act of displaying details of a single response in a streamlined way.

#Http request analysis full

Plus theyвЂ™re free and full of functionality. This is because theyвЂ™re easy to use and produce a clean output. Online ToolsДЄfter you find an online request tool you like, it will quickly become your most frequented URL. Below weвЂ™ll cover these browser-specific tool as well as other tools that make header inspection easy, even easy to automate. There are hundreds of tools available for generating and inspecting responses, including tools within browsers like Chrome and Firefox. A common use case with no-store is to prevent a cache from storing sensitive data such as login information or banking details. no-store prevents a cache from storing the response.

no-cache / no-store - no-cache prevents a resource from being cached, forcing the cache to revalidate the resource each time itвЂ™s requested.

If set to private, the response wonвЂ™t be cached by a proxy or CDN.

public / private - These dictate whether or not a response is intended for a specific user.

proxy-revalidate - proxy-revalidate is similar to must-revalidate, except it applies only to proxies.

If must-revalidate is set, the cache has to honor any lifespan limitations set on a resource regardless of the clientвЂ™s configuration. In some cases, a cache may deliver stale content based on the clientвЂ™s configuration.

must-revalidate - This forces a cache to validate the вЂњfreshnessвЂќ of a resource before delivering it.

An alternative in this case would be to use X-Accel-Expires. Nginx doesnвЂ™t honor this header, which means it doesnвЂ™t apply to some CDNs.

s-maxage - The s-maxage header is identical to max-age except itвЂ™s designed specifically for proxies such as CDNs.

(This header overrides the previously used вЂњExpiresвЂќ header.) When the max age is reached, the cache requests a new copy from the origin.

max-age= (time in seconds) - This tells the cache how long to store a resource before it expires.

Some of the more common Cache-Control values are listed below. These values are usually set by the origin server and interpreted by any caching mechanism that receives the resource, including the userвЂ™s browser. It consists of several values that define how a resource should be cached. The Cache-Control header determines many of the actual caching mechanisms. This header determines your cache hit ratio and is affected by your caching policy. If the resource was fetched from the origin server, the header reads MISS. X-Cache describes whether or not a resource was served from a CDN. LetвЂ™s go over two of the more relevant headers for CDNs: X-Cache and Cache-Control. This makes it easier to identify and troubleshoot problems that wouldnвЂ™t otherwise be apparent. In the context of CDNs, headers sent in response to a request from a user tells you about the performance and availability of a cacheable asset. HTTP headers carry critical information about the delivery of HTTP objects. Familiarizing yourself with these headers will make test results more valuable to you as a CDN user. But before reviewing the tools, letвЂ™s go over the headers that are specific to CDNs and caching. Depending on your preferences and feature requirements, one tool will work better for you than another. While there are hundreds of tools available for generating HTTP responses, in this post weвЂ™ll cover those that are the most popular. This is where HTTP request tools come in handy. But to generate a response, first you need to send a request. Knowing what to look for in a response can help you optimize content delivery and troubleshoot CDN-related issues. Not only do they describe the resources being fetched, but they give insight into how those resources were delivered. HTTP headers can tell you a lot about the state of your CDN, web server and API. This post was originally posted on the MaxCDN Blog and has been updated with the latest HTTP request tools.