ICTWEB424 Evaluate and select a web hosting service

Transcription

1 ICTWEB424 Evaluate and select a web hosting service Learner Guide

2 Copyright, 2015 by North Coast Date last saved: 13 October 2015 by Sharon Lehman Version: 1 # of Pages = 22 ICT team Content writer and course adviser Resource Development Team Instructional and graphic design Copyright of this material is reserved to the Crown in the right of the State of New South Wales. Reproduction or transmittal in whole, or in part, other than in accordance with the provisions of the Copyright Act, is prohibited without written authority of North Coast. Disclaimer: In compiling the information contained within, and accessed through, this document ("Information") DEC has used its best endeavours to ensure that the Information is correct and current at the time of publication but takes no responsibility for any error, omission or defect therein. To the extent permitted by law, DEC and its employees, agents and consultants exclude all liability for any loss or damage (including indirect, special or consequential loss or damage) arising from the use of, or reliance on, the Information whether or not caused by any negligent act or omission. If any law prohibits the exclusion of such liability, DEC limits its liability to the extent permitted by law, to the re-supply of the Information. Third party sites/links disclaimer: This document may contain website contains links to third party sites. DEC is not responsible for the condition or the content of those sites as they are not under DEC's control. The link(s) are provided solely for your convenience and do not indicate, expressly or impliedly, any endorsement of the site(s) or the products or services provided there. You access those sites and use their products and services solely at your own risk.

3 Contents Getting Started... i About this unit... i Elements and performance criteria... i Icon Legends... ii Topic 1 Hosting services... 3 What is a host?... 3 What is a server?... 4 What is a web server?... 5 What kinds of web hosting service are there?... 6 The common types of hosting... 7 Features and benefits from different web hosting providers... 9 How can I be sure the hosting service does what it says it does? How long do I have to wait for help? What kinds of web hosting client are there? Summary... 18

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5 Getting Started About this unit This unit describes the skills and knowledge required to determine a client s current and future internet service providers (ISPs) needs. It applies to individuals working in information and communications technology (ICT) who take responsibility for comparing and evaluating internet service provider (ISP) services, and are technically adept and proficient communicators, with a broad knowledge of internet technologies. Elements and performance criteria Elements define the essential outcomes of a unit of competency. The performance criteria specify the level of performance required to demonstrate achievement of the element. They are also called essential outcomes. Follow this link to find the essential outcomes needed to demonstrate competency in this Unit: i P age

6 Icon Legends Learning Activities Learning activities are the tasks and exercises that assist you in gaining a clear understanding of the content in this workbook. It is important for you to undertake these activities, as they will enhance your learning. Activities can be used to prepare you for assessments. Refer to the assessments before you commence so that you are aware which activities will assist you in completing your assessments. Case Studies Case studies help you to develop advanced analytical and problem-solving skills; they allow you to explore possible options and/or solutions to complex issues and situations and to subsequently apply this knowledge and these newly acquired skills to your workplace and life. Discussions/Live chat Whether you discuss your learning in an online forum or in a face-to-face environment discussions allow you to create and consolidate new meaningful knowledge. Readings (Required and suggested) The required reading is referred to throughout this Learner Guide. You will need the required text for readings and activities. The suggested reading is quoted in the Learner Guide, however you do not need a copy of this text to complete the learning. The suggested reading provides supplementary information that may assist you in completing the unit. Reference A reference will refer you to a piece of information that will assist you with understanding the information in the Learner Guide or required text. References may be in the required text, another textbook on the internet. Self-check A self-check is an activity that allows you to assess your own learning progress. It is an opportunity to determine the levels of your learning and to identify areas for improvement. Work Flow Shows a logical series of processes for completing tasks. ii P age

7 Topic 1 Hosting services As a Web Developer you will be creating and maintaining web sites on a regular basis. When other people need to see these sites, where are they placed? They could be anywhere as long as they are hosted on a computer connected to the internet. You could host the website yourself as in house, your employer could also have their own dedicated web servers, or you could outsource it and have someone else to host it for you. But before we go any further we need to ask the question. What is a host? In networking speak, a host is an end-point (a node) on the internet. It can be a large or small machine that sends or receives end-user data. Each host has its own unique IP address formed by the computer's local number and the particular number of the network it belongs to. 3 P age

8 A network host doesn t always distribute web pages to end users but could also host video files, serve as a dedicated server or used purely for remote backups. What is a server? Network-based or distributed computing has data processed on different end-points of a network. At one end-point can be a client computer or device, an example of this is an internet browser that sends a request for data (the web page). Another end-point can be a server, e.g. a web server that continuously listens for requests and responds to them with the web page(s) you requested. The client-server connection only works if the end-points share the same application layers and relevant protocols. For a standard web based client-server connection this is HyperText Transfer Protocol (HTTP). It is good to note one server can work with many clients at once and vice versa. Servers come in many different types which don t always serve up web pages. There are servers for: > Files > Databases > Mail > Applications > DNS Domain Name System > Game Servers. Each of these types of servers often utilise their own relative protocols depending on the purpose the server is being used for. ADDITIONAL RESOURCES RECOMMENDED 1 Follow this link for definitions of the various types of servers: > 4 P age

9 LEARNING ACTIVITIES ACTIVITY 1 The Webopedia link above will have basic explanations of the protocol list below, but to see a full range of the available suites of protocols try the following link: Now find the correct server types for the following list protocols. > FTP (File Transfer Protocol) > SQL (Structured Query Language) > SMTP (Simple Mail Transfer Protocol) > SOAP (Simple Object Access Protocol) > POP3 (Post Office Protocol) > SSH (Secure Shell) What is a web server? A web server is a host computer which provides (serves) web pages to an end user. Generally this is simply sending the entire contents of files via the Hypertext Transfer Protocol (HTTP). The most common and basic structure of the web pages relies on the HyperText Markup Language (HTML) as the programming language used to structure a web document. A web server can do much more by running applications or programs installed on the server. This allows for more dynamic websites which can respond and provide different and relevant information according to user interactions with previous or current pages. Often this is used for retrieving and modifying information from databases. Server based programming languages are generally used for these types of database interactions between the client and server. But for now we get back to the basics. 5 P age

10 Any end-point of the internet can communicate with another end-point using TCP/IP: > Transmission Control Protocol (TCP ensures reliable delivery of packets containing application layer data. > Internet Protocol (IP) is responsible for addressing information that enables data packets to be routed in a network. Both are examples of transmission layer protocols, these protocols use a port number that allows many applications to share the same end-to-end connection. By default, common servers use common ports to listen for requests: > Web servers using HTTP listen on port 80 > Web servers using HTTPS (HTTP Secure, also known as SSL, Secure Sockets Layer) listen on port 443. Non-default port numbers can be configured, often used in servers for games or purpose built software. What kinds of web hosting service are there? Web hosting services may be offered local and overseas. There are pros and cons with both. You will need to think about some of the factors associated with this when evaluating if the host is local or overseas. Local > Do they speak your language? > Are they in your time zone? > Is advice and support free for setting up or does it cost extra? Overseas > Often less expensive due to economies of scale > Sometimes close to target client base 6 P age

11 The common types of hosting There are four major types of hosting services available. Dedicated stand-alone hosting An entire physical machine supplied by the hosting service with exclusive use by the customer. Often management software may also be supplied to ease remote control by the client, e.g. cpanel or Plesk are common. ADDITIONAL RESOURCES RECOMMENDED 2 Follow this link for a comparison of web hosting control panels Co-hosting or co-located This is where the customer supplies a physical machine but uses the hosting service infrastructure, for example: > power > network > air-con > physical security Often it is easier to initially setup in-house although management software may also be supplied by a hosting company. ADDITIONAL RESOURCES RECOMMENDED 3 Follow this link for more information on colocation centres: 7 P age

12 Virtual Private Server (VPS) A VPS is physical machine which runs a number of virtual machines; each of these virtual machines is a program that thinks it is running on its own physical machine. An example of this is VMware and some benefits are: > less physical machines needed > less maintenance better reliability > less power consumption > each virtual machine can run one or more servers. ADDITIONAL RESOURCES RECOMMENDED 4 Follow this link for more information on virtual private servers: Clustered or cloud hosting This is where a number of physical machines sharing a number of VPS s. The physical machines are connected together by high a speed network which gives an easy advantage to add more physical machines or scale up. ADDITIONAL RESOURCES RECOMMENDED 5 Follow this link for more information on clustered web hosting: 8 P age

13 LEARNING ACTIVITIES ACTIVITY 2 If you already have web hosting account, make sure you can ftp to the account and upload html files and view them. If you don t have an account, tafenow@tafensw.edu.au asking for an account to be created so you can. Please put Web Hosting account request in the subject. Your online teacher will reply with the correct details and a guide for doing so. Features and benefits from different web hosting providers Cost Budget and value customers will look for competitive pricing after side-by-side comparison of other features. Hosting companies often have monthly plans but you can get betters deals by paying up front for a year or two in advance. Payment Individual and small business customers will be happy with credit card or bank transfers. Medium to large business customers will want an account with delayed payment terms. Performance Larger customers will be after higher traffic, but even individual customers who have media rich content (e.g. streaming video) will want high performance. Reliability All businesses will be after high reliability, downtime = lost business = money! 9 P age

14 support All good business websites provide receipts and shipping confirmations via which keeps their customers informed and helps build their trust. A hosting service should always come with a POP3 and IMAP account. Normally there is no limit of addresses you can add to your domain. Scripting support For web applications that interact with the client such as PHP (Hypertext Preprocessor) based shopping carts, database support. Configuration Without a doubt the first and most important question you should ask a hosting provider is What control do I have over web server configuration? Many of the easiest and most important performance improvements you can make to your web application, such as HTTP compression and caching, are configured at the web server level. Storage of business data Database holding online order details that can be accessed via server scripting. Popular relational web hosting databases include: > MySQL (it's powerful, it s free, and it is popular) > Microsoft SQL (MS SQL) (powerful and very popular on Windows servers - not free) > PostgreSQL (free but includes a few more advanced features than MySQL). Logging This allows for reliability, performance and security monitoring often with a control panel or management interface. Management interface Allows clients to remotely control web server features and settings through the use of a control panel. 10 P age

15 Hosting control panel software commonly lets you: > Add domain names > Add and manage accounts > View visitor statistics > View server errors and log files > View disk space and bandwidth used > Upload and edit files > Set-up and manage databases > Manage FTP users In addition, some web hosting control panels let you: > Set-up spam filtering > Make back-ups > Set-up SSH logins > Enable HotLink and Leech Protection > Password protect directories > Configure scripting languages > Set-up cron jobs > Install scripts > Install free Content Management Systems (CMS) such as Wordpress, Joomla > Install free Blogging tools and Discussion Forums How can I be sure the hosting service does what it says it does? To manage any kind of system you must measure what matters. With this in mind there are automated tools for measuring web hosting. Uptime or availability By periodically sending and receiving a test message to the web server you can check if the server is up or online. Traditionally this has been done with a PING (Packet INternet Groper), sometimes known as an Echo Request. 11 P age

16 Since ping messages have been used by hackers to flood network connections, many routers have now been configured to block them so an alternative is to use HTTP requests and responses to and from a dummy web page on the web host. LEARNING ACTIVITIES ACTIVITY 3 Sign up to a free account on Add your one free check using the details in the image below. 12 P age

17 After adding the check let it run for a while, 10 minutes, an hour, a day. After some time come back to the check and monitor the progress by selecting some of the reports pingdom can generate as below. Performance This can be measured by response time, how long does it take for the response to start, the throughput and finally how fast the entire response has taken. The response is often measured in bytes or transactions per second. LEARNING ACTIVITIES ACTIVITY 4 Go to and enter the site Run a web page test and view the results. Try other websites at peak and off peak times and review the performance. 13 P age

18 These reports are needed to provide evidence to the hosting service. They should show activity against time. A good hosting provider will display both peak and off-peak activity. How can I get services fixed? A good web hosting service will be constantly monitoring for problems and be pro-actively fixing them. A help desk should also be a convenient method for clients to report errors with the option of correspondence via website, voice, and SMS. They should anticipate common problems and install a strategy to rapidly fix them. Redundancy This means that additional components are on stand-by to instantly take over components such as processors, storage, network connections and power supplies. With these excess components you can understand any redundancy comes at a high cost. A common redundancy technique for data is RAID (Redundant Array of Independent or Inexpensive Disks). RAID is where many hard disks act as one. They can be configured to mirror data in case one disk fails, do not confuse this with data backup. Data backup is usually separate from mirroring and should be stored is in a separate location. There are pro and cons with off-site backup. It does takes longer to restore but complete data is not lost if site suffers catastrophe. ADDITIONAL RESOURCES RECOMMENDED 6 Follow this link for more information on redundancy: Integrity Data integrity means the original data can be accessed without corruption whereas data security means that data does not fall into the wrong hands. All good web hosting services will ensure a high degree of both electronic and physical protection. 14 P age

19 > They will require strong passwords for remote administration. > They will have a locked and alarmed data centre How long do I have to wait for help? Stuff happens; things break often out of our control, waiting for a web hosting service to fix a problem could cost your business. The term used for this is called the service time, i.e. the response time to a service request or ticket. If the service time is too long there needs to be a procedure where the client can have the problem escalated. This usually means that more resources are brought to bear on the problem by the service provider. Not usually more people but a technically higher level (more expensive and experienced) person. A good web hosting service should supply automated service reports for outages and maintenance which affect services, they should periodically report any problems and how long they took to fix them. Open signing up for a hosting service you will agree to a SLA (Service Level Agreement) An SLA is a negotiated contract and describes: > How fast different types of problems should be fixed during various times of the week > The escalation procedure > How much the client should pay for this level of service > What penalties apply if the service provider defaults > A procedure to resolve service level conflicts. A good web hosting service should be easy to contact to review reports on: > Hosting performance > Service levels > Costs 15 P age

20 What kinds of web hosting client are there? In the technological sense of client Web browsers do a lot of the work to display content on many different platforms. Hardware > Desktops/Laptops > Mobile phones > Tablets Software, Operating System (OS) > Proprietary > Open source In the business sense of client - the customer Budget hosting Where a client prefers to pay the least for what is needed: > e.g. Students > Not for profit organisations > Businesses with a limited budget Value for money hosting Where a client wants to pay the least for the most and look for package deals that suit their needs, e.g. small businesses. Premium hosting Often when we want the best with the least effort, e.g. big business. Whatever the situation is today it very likely to change, hopefully with more business activity. Will the hosting service easily accommodate that need to change? This is called capacity planning. 16 P age

21 ADDITIONAL RESOURCES RECOMMENDED 7 Use this web site to make a preliminary investigation for your assessment P age

22 Summary Choosing a web hosting service requires a professional consideration of the intended uses of the website. Knowing the questions to ask your employer and yourself will enable the business plan (objectives) into action. Supportive strategies can then be put into place that align and ideally enhance the business plan objectives. This study unit has enabled you to gather a variety of resource material that will help to assess the suitability of a web hosts according to a set of assessment criteria. The assessment criterion that is provided on the preceding pages is a generalised but very good list to use as a start and which can be modified to suit your clients needs. 18 P age