Computer Science 9618 Notes

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DNS and Cloud Computing

Apr 16, 2024, 3 min read

  • DNS (Domain name system)

    • It is a hierarchical distributed database installed on domain name servers that is responsible for mapping a domain name to an IP address (it is also known as domain name service).

  • URL (Universal Resource Allocator)

  • DNS Systems

  • Allocates readable domain names for Internet hosts

  • Provides a system for finding the IP Address for an individual domain name

    • Also converts a host name into an IP a computer understands
    • This is the same for your phone’s address book (it can only dial numbers, not Pete)

  • Hierarchical distributed database installed on a large number of domain name servers covering the whole of the Internet.

  • DNS name space divided into non overlapping zones, with each one having its own primary name server with the database stored on it.

  • DNS system, URL

  • Secondary servers get info from this primary server

  • 250+ top-level domains

    • Generic (.gov, .com)
    • Or represent countries (.uk, .gr)

  • The domain name is included in a universal resource allocator (URL), which identifies a web page or an email address.

  • Cloud computing

  • Storing data online instead of on your own hard drive

    • Dropbox, iCloud, Google Drive, Streamable, YouTube, Amazon AWS, Wasabi Hot Storage, Hetzner Storage Boxes

  • Computers and servers that store our date and back it up to ensure there is still a copy if the server breaks down

  • Public Clouds

    • Eg amazon, Microsoft, google, OVH, Hetzner

    • Services and infrastructure provided and shared by all customers

    • Massive amounts of available space – easily scalable

    • Give access to IaaS and SaaS

      • Infrastructure as a Service (IaaS) – a virtualised infrastructure
        • providing processing power and storage
      • Software as a Service (SaaS) – specialised software programs that
        • are easy to implement and use

    • Advantages: versatility; pay as you go structure to get more capacity on demand

    • Disadvantages: infrastructure and OS controlled solely by cloud provider

    • Private Clouds

      • Usually behind a firewall and used by one organisation
      • Same as public in that authorised users can access, use and share data from anywhere but no one else can
      • Advantages: security, control
      • Disadvantages: expensive (company is responsible for software and infrastructure), not as scalable

    • Cloud computing drawbacks

      • Worry about security – not “in charge” of storage
      • Privacy – usernames, passwords, authentications methods needed
      • Who owns the data?
      • No Internet = no data

    • Cloud computing benefits

      • Access data and files anywhere any time
      • Reduced hardware costs
      • Don’t need for physical space to store servers (servers will be at cloud company’s site)

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