Building Managing Web Sites Webserver Fundamentals 12142021 1999

Server Fundamentals • Software that answers requests for files, printing, communications, etc. • Server software normally accessed by many different users via a network. • Server software normally run on a dedicated computer (“box”). • The “Box” is often called a server as well. • Server boxes typically more powerful than workstations. 12/14/2021 © 1999, 2000 Valtara Digital Design/Blitzkrieg Software 2

Web Server Fundamentals A webserver is software that does the following: • Server receives requests from browser/client for resources – A resource is any chunk of information that can be identified by a URL like HMTL or image files, scripts, streaming media, etc. • • Server retrieves and/or processes the resource Server sends the resource back to the client Server logs the transaction Responses/requests occur using the HTTP protocol, typically on port 80 12/14/2021 © 1999, 2000 Valtara Digital Design/Blitzkrieg Software 3

Sample HTTP Exchange To retrieve the resource at http: //www. host. com/path/file. html Browser sends request to host www. host. com, port 80: GET /path/file. html HTTP/1. 0 From: 156. 123. 456. 798 User-Agent: Mozilla/4. 01 The server sends a response back to the client: HTTP/1. 0 200 OK Date: Fri, 31 Dec 1999 23: 59 GMT Content-Type: text/html Content-Length: 1354 <html><body><h 1>Happy New Millenium!</h 1> (more file contents) </body> </html> 12/14/2021 © 1999, 2000 Valtara Digital Design/Blitzkrieg Software 4

Common Response Status Codes • 200 OK - Request succeeded, resulting resource is returned in the message body • 404 Not Found --The requested resource doesn't exist. • 301 Moved Permanently • 302 Moved Temporarily • 303 See Other (HTTP 1. 1 only) Resource has moved to another URL (given by the Location: response header), and should be automatically retrieved by the client. • 500 Server Error -- Unexpected server error. Common caused by a server-side script that has bad syntax, fails, or otherwise can't run correctly. 12/14/2021 © 1999, 2000 Valtara Digital Design/Blitzkrieg Software 5

Web Server Fundamentals • Webservers process response/requests, log activity, and handle scripts. • Personal Web Server a good example. • BUT -- Life gets complicated when… – Additional services are desired (FTP, Listservers, NNTP, Streaming Media, etc. ) – Server-side dynamic content can quickly overwhelm a server “box” 12/14/2021 © 1999, 2000 Valtara Digital Design/Blitzkrieg Software 6

Establishing a Web Presence • Different paths for different needs: – Develop a small local webserver (PWS). – Use space provided by your ISP. – Lease space with a web hosting service. – Lease a server with a web hosting service. – Create and manage your own webserver. – Create and manage a webserver farm. 12/14/2021 © 1999, 2000 Valtara Digital Design/Blitzkrieg Software 7

Key Considerations (1) • Web site goals and architecture – – Static vs. dynamic content Internet vs. Intranet vs. Extranet Domain name required? Special technologies needed for some resources (e. g. , streaming media, secure e-commerce)? • Resources (Time, money, and expertise) A balance between: – How much can you spend (including personnel)? – How much time and expertise do/can you have? 12/14/2021 © 1999, 2000 Valtara Digital Design/Blitzkrieg Software 8

Key Considerations (2) • Site Usage – How much traffic initially and in future? – Secure access required for some/all of content? • Control and Accountability – What level of service/support is acceptable? – Who gets the blame? • Technology – Are specific platforms/technologies required (e. g. , Unix vs. NT, Front. Page Server Extensions)? 12/14/2021 © 1999, 2000 Valtara Digital Design/Blitzkrieg Software 9

Develop a small webserver • Use Personal Web Server or other free/inexpensive webserver software locally. • Can use nearly any type of computer. • Typically used only for very small Intranets (10 -50 users) or development purposes. • Low or no cost. • Limited number of connections possible. • Limited capabilities and reliability. 12/14/2021 © 1999, 2000 Valtara Digital Design/Blitzkrieg Software 10

Using your ISP • Many ISPs offer space on their webservers. Typically access pages via FTP. • Minimal or no cost. • Most ISPs provide few capabilities (limited dynamic content, no Front. Page Extensions, etc. ) • Limited reliability and support – not a primary business activity for ISPs. • No domain name gives less professional impression. 12/14/2021 © 1999, 2000 Valtara Digital Design/Blitzkrieg Software 11

Using a “free” service • Other sites offer free web sites • Typically must include advertisements or other promotions in your web pages • Limited disk space • Example: – Geocities (www. geocities. com) • Check out http: //www. freewebspace. net/ 12/14/2021 © 1999, 2000 Valtara Digital Design/Blitzkrieg Software 12

Web hosting services Leasing space • Many companies specialize in providing equipment and services to “host” your web site. • They set up multiple “virtual webservers” on their webservers. • Server and maintenance costs spread among many users. • Most services will handle registering your domain. • Typical monthly costs (comparison difficult): – Bare bones $10 -20 – Front. Page Extensions, ASP, etc. $25 -35 – Small/medium e-commerce site, $35 -65 12/14/2021 © 1999, 2000 Valtara Digital Design/Blitzkrieg Software 13

Web hosting services Advantages • Low entry cost • Service monitors your virtual server: 24 hours, 365 days/yr. • Most offer multiple links to the Internet backbone. • Most services claim/offer high uptime (98%+). • Service manages hardware and server maintenance. 12/14/2021 © 1999, 2000 Valtara Digital Design/Blitzkrieg Software 14

Web hosting services Disadvantages • • • Sharing server causes less reliable response times. Quality, support, and professionalism vary widely. Very competitive -- some go under. Very difficult to compare prices. Hassles moving from one service to another. 12/14/2021 © 1999, 2000 Valtara Digital Design/Blitzkrieg Software 15

Web hosting services Leased servers • Typically have expensive multiple, redundant connections to Internet. • Control of your server through Root or Administrator access. Typically connect using PC Anywhere or similar software. • Services typically offer uninterruptible power supply and generator back-ups. • Typical monthly costs: • $200 -1000 depending on machine and features. 12/14/2021 © 1999, 2000 Valtara Digital Design/Blitzkrieg Software 16

Web hosting services Shopping hints • Define everything you must have (or will need) before you shop (FP Extensions, ASP, Index Server, CGI, etc. ) • Use Hosting Service pages to identify good prospects: – http: //www. hostsearch. com/ – http: //www. webhosters. com/ 12/14/2021 © 1999, 2000 Valtara Digital Design/Blitzkrieg Software 17

More shopping hints • Compare services/prices carefully. – You get what you pay for – if it sounds too good to be true, it is! – Look for at 20 MB of disk space for growth. – Be careful of bandwidth – look for 1 GB monthly minimum. – Ask for specific on SSL implementations. – Domain registration should be free (although Inter. NIC will charge you $70 for two years registration) • Ask for a list of sites they are currently hosting. – Check periodically for availability/response. – E-mail webmaster for a quick comment of the service 12/14/2021 © 1999, 2000 Valtara Digital Design/Blitzkrieg Software 18

STOP AND THINK HARD! • Before you think about managing your own webserver, explore all outsourcing options. • Managing your own webserver is resource intensive. • Don’t do it unless you need very high control/accountability, extreme reliability, or special technologies. • Outsourcing is getting better and better… 12/14/2021 © 1999, 2000 Valtara Digital Design/Blitzkrieg Software 19

What you need for your webserver • Staff – Knowledgeable and/or trainable staff in web management • Connectivity – A dependable connection to the Internet. • Server – A server box(s) for your webserver software and web content. • Webserver software – Software to handle HTTP requests for resources. 12/14/2021 © 1999, 2000 Valtara Digital Design/Blitzkrieg Software 20

Staffing • Training takes time – Expertise takes longer! – Start small and build up… • Hiring experts in-house takes time and is difficult. – Limited pool of experts • Contractors are costly… – You will spend much time working with and managing your contractors. – If use contractors, try to have contractors train your inhouse staff. 12/14/2021 © 1999, 2000 Valtara Digital Design/Blitzkrieg Software 21

Connecting to the Internet (1) • Dial-up or Dedicated Phone Line – Use an analog modem (up to 56 kbps) via the PSTN (Public Switched Telephone Network) – Low-cost, available everywhere, slow, analog/digital translation introduces problems, long-connection time, not scalable • ISDN (Integrated Services Digital Network) – Connections between 64 -128 kbps. – Pretty good cost/value, pretty good availability (uses existing lines), continuous connection possible, limited scalability 12/14/2021 © 1999, 2000 Valtara Digital Design/Blitzkrieg Software 22

Connecting to the Internet (2) • DSL/ADSL – Digital Subscriber Lines • Provides a dedicated digital circuit between a residence and a telephone company's central office • A is for asynchronous – different speeds coming in and going out – not ideal for a busy webserver. • Current typical speeds of 1. 5 MBPS downstream and 384 KBPS upstream (or 384/128 KBPS). • Must be located within about 17, 500 feet of their central telephone switching office. • Costs in flux – $35 -200/month • Good value, continuous connection, limited scalability 12/14/2021 © 1999, 2000 Valtara Digital Design/Blitzkrieg Software 23

Connecting to the Internet (3) • Digital Data Service (DDS) – Lease a digital line from a ISP or Telco. – Requires a dedicated line and some type of unit (Channel Service Unit/Data Service Unit) for converting signals & protecting provider’s network – Available in many forms: fractional T 1, T 3, etc. – Most common connections at: • DS 1/T 1 – 1. 544 mbps • Fractional DS 1/T 1 available in 64 kbps increments • DS 3/T 3 – 44. 736 mbps (typically used by ISPs) – Typical costs: $1000/month plus ISP costs 12/14/2021 © 1999, 2000 Valtara Digital Design/Blitzkrieg Software 24

Setting up a Server • General considerations – Avoid future problems and costs by purchasing off-theshelf, name-brand systems and components. – Purchase as much machine (“more power!”) as you can afford. – Purchase a service agreement. – Locate server in clean, cool, dry location. – Make sure the equipment you buy will work with the operating system. • For NT, see: http: //www. microsoft. com/isapi/hwtest/hcl. idc 12/14/2021 © 1999, 2000 Valtara Digital Design/Blitzkrieg Software 25

Basic Server Security • Server “box” should be in a physically secure location. • Webservers should be located carefully on LANs. – Webservers located within a LAN should not be located on busy network segments. – Routers can filter inappropriate packets. – Firewall software/hardware can be used to screen traffic more carefully. – Ideally, Internet servers should be outside LAN. 12/14/2021 © 1999, 2000 Valtara Digital Design/Blitzkrieg Software 26

Server Operating Systems • Windows NT Server – – GUI orientation Lower entry cost… Mass market appeal Integrated with other Microsoft products • Unix - Solaris/HP-UX/AIX/SCO/s 5 r 4 – Not cheap – Well supported – Additional web server required (most of the time) • Unix – Linux/Free. BSD – Cheap – Support issues – Includes Apache webserver, most popular in the world 12/14/2021 © 1999, 2000 Valtara Digital Design/Blitzkrieg Software 27

Server CPU • Buy as much as you can -- stay behind leading edge. • Static content requires considerably less CPU than dynamic content. • Consider whether dynamic content can be presented/converted into static content. • Partition dynamic content onto separate servers to increase performance. • Server with average CPU load of >60% needs upgrading. 12/14/2021 © 1999, 2000 Valtara Digital Design/Blitzkrieg Software 28

Server Memory • The most critical portion of a webserver. • Don’t skimp. Buy as much as you can afford! • Commonly used resources (e. g. , web pages) are cached in memory. • Many webservers run multiple services, each which require memory. • Consider your memory upgrade path. • For Windows NT webservers: – 128 MB is bare bones – 256 MB is a good entry point – Rumor: Windows 2000 happy at 512 MB 12/14/2021 © 1999, 2000 Valtara Digital Design/Blitzkrieg Software 29

Server Hard Disks • 3 -5% chance of failing over a 3 year period. • SCSI better (but more expensive) than ATA/IDE. – Typically better throughput. – Multiple drives can be active simultaneously. – Supports RAID arrays. (see next slide) • Better to have multiple disks – o/s and services on one – data on additional disks • Isolate differing parts of a site on different volumes • Particularly place data on a different “spindle” then you FTP content or web pages 12/14/2021 © 1999, 2000 Valtara Digital Design/Blitzkrieg Software 30

RAID Arrays • RAID (Redundant Array of Independent Disks) joins several disks together to increase performance and fault tolerance. • RAID 1 or 5 is usually the best choice for a Web server. • RAID 1 (disk mirroring): data written to redundantly to two separate hard drives working together. – Should one drive fail, the others can take over automatically. • RAID 5 (Striped Volume Sets) – Even higher reliability across multiple volumes. Can be “hot swapped”. 12/14/2021 © 1999, 2000 Valtara Digital Design/Blitzkrieg Software 31

Other Server Features • CD-ROM • Use a quality (expensive) network interface card (NIC), which unburdens CPU. • Quality SCSI/disk controller card • Back-up technologies – Tape – Optical media – CDR and CD/RW 12/14/2021 © 1999, 2000 Valtara Digital Design/Blitzkrieg Software 32

Configuring NT as a webserver • Boot drive should be NTFS for security. • Swap file should be on a separate physical disk from the operating system. • FTP Server should be on its own partition to avoid filling attacks that fill up drive. • Optimize o/s for server operation. • Disable unnecessary services. • Avoid loading unnecessary network protocols. • If have multiple web servers, configure them the same for simpler maintenance. 12/14/2021 © 1999, 2000 Valtara Digital Design/Blitzkrieg Software 33

Webserver Software Top placed servers in March 1999 Source: http: //www. netcraft. com/survey Apache 2, 409, 056 Microsoft-IIS 1, 030, 892 Netscape Enterprise 205, 645 Rapid. Site 85, 076 Web. Site Pro 78, 515 12/14/2021 © 1999, 2000 Valtara Digital Design/Blitzkrieg Software 54. 89% 23. 49% 4. 69% 1. 94% 1. 79% 34

IIS - Internet Information Server • Includes many services and features: – Web services (HTTP) – Front. Page Server Extensions – Supports CGI, and more importantly Active Server Pages (ASP) – Content Indexing (Index Server) – FTP Server (FTP) – Certificate Server – Newsgroups (NNTP) – Mail services (SMTP) – Transaction/Application Server (MTS) 12/14/2021 © 1999, 2000 Valtara Digital Design/Blitzkrieg Software 35

IIS Gotchas and Tips • Requires NT Server and latest version of Internet Explorer. • Don’t use IIS 3, upgrade to IIS 4. • Keep up to date with service packs and patches. – Particularly be aware of IP related security patches – If things are working, wait a little before installing service packs. 12/14/2021 © 1999, 2000 Valtara Digital Design/Blitzkrieg Software 36