Caching and Its Main Types

Caching and Its Main Types

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  Caching and ItsMain Types
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  Table of Contents 2 Introduction Caching WebBrowser Web Browser Cache’s Function Clearing a Browser Cache Major Types of Caching Web Caching (Browser/Proxy/Gateway) Data Caching Application/Output Caching Distributed Caching Conclusion
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   The contentof this PPT is meant for providing information on the process of caching and its different types. Despite having encountered the term “caching” frequently, many are unaware of what it entails.  The information contained in this PPT will prove to be useful for understanding the concept of caching. 3 Introduction
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  The process ofcaching involves storage of files’ copies in a cache or in a temporary location for storage. This is meant for accessing the files more quickly. Usually, a cache indicates a storage location that is temporary in nature and is meant for data or copies of files. Some examples are-  Web browsers which cache JavaScript, images and HTML files for the purpose of loading websites quickly.  DNS servers which cache DNS records to ensure faster lookups.  CDN servers cache content to ensure reduction in latency. 4 Caching
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   A webbrowser, which is commonly known as a browser, is essentially an application software that serves the function of accessing the World Wide Web. The use of web browsers happens on a range of devices, which includes laptops, smartphones, tablets, desktops, etc.  Every user of the Internet needs to have a web browser installed in his device in order to connect to the server of a website and to display the web pages of that website. The contents of websites are stored in the form of files on the web servers of web hosting companies and are processed on it and delivered from there to the web browsers. Whenever a user looks for a certain web page on the Internet, the web browser retrieves its contents from the corresponding web server and displays the web page on the device of the user.  Web hosting service providers that provide excellent web hosting services are often referred to as the “Best Web Hosting Company”, the “Best Cloud Hosting Company”, the “Best Windows Hosting Company”, etc. 5 Web Browser
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   Each timethat a web page loads onto a user’s device, the web browser has to download a huge volume of data for the purpose of displaying the web pages.When browsers cache most of the content of the webpage, it shortens page load times by saving a copy of the content of the web page on the hard drive of the device of the user.The next time that the user visits the same web page and its contents get loaded onto the user’s device, the page loads comparatively faster, as most of the site’s contents are already stored locally.  These files are stored on the browsers till their TTL expires or until the cache of the hard drive is full, whichever happens earlier.TTL refers to Time to Live and indicates the duration for which content needs to be cached. It is also possible for users to clear their browser cache. 6 Web Browser Cache’s Function
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  7 1-800-123 -8156 Whoa!That’s abig number, aren’t you proud?
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   The resultof deliberately clearing a browser cache by a user is that web pages, despite being revisited, would load in a way as if those were loading for the first time.The advantage with regard to faster web page loading would cease to exist.  One advantage of clearing a browser cache is that if any web content didn’t load correctly the first time and was cached, it might load correctly on clearing the cache.The biggest disadvantage of clearing the browser cache reflects in slow page load times. 8 Clearing a Browser Cache
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  Web development andweb hosting typically entails four main types of caching.These are as follows-  Web Caching (Browser/Proxy/Gateway)  Data Caching  Application/Output Caching  Distributed Caching Next, each of these four types of caching will be elaborated on, individually. 9 MajorTypes of Caching
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   Although Browser,Gateway and Proxy caching work in different ways; these cater to the same goal of reducing overall network traffic and latency. Browser caching is controlled at the individual user level. On the other hand, proxy and gateway are on a much larger scale.The latter, proxy and gateway, enable the sharing of cached information across larger groups of users. Usually, cached data can be DNS (Domain Name Server) data, which is used for resolving domain names to IP addresses and mail server records.This data type doesn’t change frequently and can be cached for a long duration by the Proxy and/or Gateway servers.  Browser caching enables faster navigation with regard to the web pages that have been visited recently. This caching feature, which is free, is often overlooked by most hosting companies and developers.The presence of Cache-Control and ETag headers is required by this process, for instructing the browser of the user to cache certain files for a certain duration of time. 10 Web Caching (Browser/Proxy/Gateway)
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   Database drivenapplications as well as CMS solutions reap the benefits of data caching. This type of caching serves well for frequent calls to data, which don’t alter rapidly. Data caching enhances user experience by ensuring that websites and applications load faster. This is attained by cutting down on extra visits to the DB for retrieving data sets which are known to have not changed. Data are stored on the server’s local memory and provide the fastest route for retrieval of information on a web server. The less the number of DB calls, the better it is. Usually attempts are made by most of the DB solutions to cache those queries that are frequently used. This is done to ensure reduction in turnaround time.  Standard practice calls for clearing of any cache data post data alteration. This ensures that the front- end of CMS always has the most recent data and prevents it from hitting the database for each user that hits a page. Memory issues can result from the overuse of data caching, due to constant addition and removal of data to and from cache. 11 Data Caching
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   Application/Output Cachingensures a drastic reduction in website load times as well as reduces server overhead.This type of caching differs from data caching, wherein raw data sets are stored. Server level caching techniques, which cache raw HTML, are often utilized in application/output caching. It delivers page load times that are almost 50% faster. 12 Application/Output Caching
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   Distributed Cachingenables web servers to pull and store from the memory of distributed servers. It is used by most of the high-volume systems, such as Amazon,YouTube, etc. Post implementation, it enables the web server to serve web pages without having to face any issue with regard to running out of memory. In it, the distributed cache is made of a cluster of machines that serve memory.A new machine of memory can be added at any time when the cluster has been set up and this can be done without causing any issue to existing users. Distributed caching provides a powerful solution once it is deployed. Memcached for Linux and AppFabric forWindows Server are some of the well-known systems. 13 Distributed Caching
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   Web cachingaids substantially in speeding up loading times.Web caches can be of many different types. Each of the different web caches proves to be useful in a different set of circumstances. Hence, it is important to not only understand the types of cache that are available but also the levels of control that these offer to end-users. 14 Conclusion
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