Web Servers
While the domain name system, web design standards, and email protocols reflect the main aspects of functionality that web servers are designed to implement on the internet for the various purposes of web publishing, ecommerce, and online communications, it is also important to look at server hardware, stack software, and data center technology as they integrate together to build a formal understanding of the web hosting industry. Web server hardware differs from desktop home and business computers in important ways due to the specialized aspects of web hosting requirements. Similarly, the operating systems and software installed on web servers are customized versions of Windows or Linux used to optimize computer hardware performance to meet these same industry-specific platform requirements. The architecture and infrastructure fundamentals of the data center environment are also designed to support the technological issues unique to web hosting professionally. By looking at all of these components individually and as they fit together into a larger system through deployment, the operation of large scale distributed networks in the web hosting industry can be better illustrated.
Worldwide Web Server Sales estimated at $52 Billion USD in 2016. Source: Server Vendor Revenue Estimates, 2Q16 (Gartner, Inc.)
Did You Know? Industry sources estimate around $52 billion in sales of server hardware in 2016, with an additional $70 billion in revenue generated from web hosting services worldwide. International business related to data center and colocation services combines for another $36 billion.
HARDWARE
Web server hardware can be benchmarked for evaluation by using three main aspects that most determine website and database performance in web hosting applications, specifically the characteristics of the CPU, RAM, and storage drives installed on the machines. With the CPU, the chip manufacturer, model, year of production, number of cores, threads, and speed are all standardized values that can be referenced for the comparison of hardware. With RAM, it is generally the total amount installed on the web server that is most important, as well as the type and particular amount of RAM allocated to each web hosting account. For storage, the differences between hard disk drives (HDDs) and solid state drives (SSDs) will most determine performance in web hosting, while the total amount of storage drive space available on a hosting plan will determine value. Most web hosting companies sell their various shared, dedicated, and VPS plans with these aspects of the underlying hardware configurations clearly labeled. For other details like the layers of the software stack installed on the web servers or the data center networking equipment used by a web hosting company, it may be more difficult to get the complete specifications for comparative platform benchmark testing due to proprietary reasons or lack of transparency in business operations.
CPU
Currently there are only two main manufacturers producing the majority of CPUs that are used in the web servers deployed by hosting companies in data centers: Intel & AMD. Intel specializes in a line of Xeon servers that use the same micro-architecture (Sandy Bridge, Ivy Bridge, Haswell, Broadwell, & Skylake) as their Core CPUs manufactured for desktop PCs and laptops. The main difference is that the Xeon chips lack integrated graphics support, have a larger available CPU cache, are optimized for more than 2x the I/O performance, and support at least two additional memory channels. Intel also manufactures a “system on a chip,” low power Atom line of server CPUs that has not gained widespread use in the web hosting industry. AMD’s Opteron line of CPUs is broadly equivalent with the Intel Xeon chips and provide competitive performance at lower comparable prices. Opteron chips include x86-based processors, ARM-based processors, and the X-series with APUs for remote graphics processing.
Like desktop PCs, there are a variety of different manufacturers for server motherboards. While Intel is the most popular, Asus, Supermicro, GIGABYTE, and ASRock are also common in the marketplace. Web servers based on Intel CPUs will support Hyperthreading, Turbo Boost, AVX, Direct I/O, and other vPro extensions by installing the drivers provided by the company on the assembled hardware after the operating system is installed. Web servers can either be built as rackmount units or tower systems, but are normally not equipped with a computer monitor. Instead a rackmount KVM system is used which is a combination of a Keyboard, Video monitor, and Mouse (KVM). Web servers also often have two power supplies built-in as a backup measure to safeguard against potential equipment failure. The other main aspect of rackmount server hardware construction is the cooling system, which is normally an internal fan that circulates the air from an external climate control environment in the data center. A custom motherboard may be used to construct multi-processor servers, provide more RAM slots, or add extra storage drive connections depending on the platform requirements of the hardware deployment.
RAM
Another main difference between web servers and desktop computers is that with a few motherboard exceptions only servers will support ECC RAM. ECC stands for “Error-Correcting Code” and this type of RAM provides a higher level of verified accuracy in data transmission and numerical computations, although with a slightly slower (~2% less) performance. Otherwise the current standard is DDR3 and DDR4 RAM in web servers:
The main difference between DDR3 and DDR4 RAM is the speed of data transmission and the voltage required by the memory chips. As with most silicon technology, the latest standards provide significant performance gains vs. the previous generation and are the preferred choice for high performance applications, whereas the older versions are available at more significant cost savings.
It is also important to remember that in web hosting, unless a dedicated server is contracted, the resources on a server will be shared. Web hosting companies vary in the amount of RAM that they allocate to shared hosting accounts. There may also be a significant difference in the amount of physical RAM and virtual RAM that is allocated to a particular hosting plan. Because the amount of RAM resources available is important to CMS script and MySQL database performance, also determining the amount of simultaneous user traffic that can be supported on a website or the number of concurrent processes that can be managed by the server on a limited web hosting plan, this factor should also be used when evaluating web hosting companies. Burstable RAM is a feature included on some VPS accounts that allows for a website to exceed its normal memory allocation limits to meet unexpected spikes in web traffic, using the available system resources on the web server on a temporary basis.
Storage
The difference between solid state drives (SSDs) and hard disk drives (HDDs) is an example of two completely different technologies that compete in doing the same task, which in this instance is file storage for computer hardware integration. Hard disk drive technology actually dates back all the way to 1956 when it was first introduced by IBM with the 350 RAMAC drive, which used 50 disks together to provide 3.75 MB of total storage capacity. HDDs function in a similar manner to phonograph or CD recordings with data encoded magnetically on a wheel or disk which spins in the unit to be read by a sensor device which may also employ laser technology. Benchmarks with HDDs are: seek time, write time, data transfer speeds, and latency. IDE, SATA, SCSI, SAS, and Fibre Channel are the main bus types used to connect storage drives to the motherboard of a computer hardware device.
In contrast to hard disk drive construction, solid state drives (SSDs) have no spinning parts but rather use Flash memory chips similar to those used in digital cameras, mobile phones, and USB drives to store data. Solid state drives are designed to work interchangeably with HDDs in computer hardware configurations, using the same ports for connections and managing the same files or software. In benchmark tests, SSDs have faster seek & write times, higher data transfer speeds, and lower latency. InMotion Hosting benchmarks revealed 20x faster access times for files on a web server using SSDs vs. HDDs with about 2x the total amount of data per second being transferred. A2 Hosting tests showed 300% better overall website performance using SSDs over HDDs on a web server. Quantifying this data:
- SSDs provide data access times as low as 0.1 millisecond, compared to 5 to 8 ms for HDDs
- SSDs can manage 6000 I/O operations per second, compared to ~400 per second on HDDs
- SSDs require 20 milliseconds to complete a server I/O request that takes 400 to 500 ms on HDDs
This benchmark data shows that when competing web hosting companies offer account storage capacity for web publishing, cloud applications, and database support on their servers, there are significant performance differences involved with the use of HDDs and SDDs for the same GB of storage provided. With this there is also a price differential, with SSD storage on average 5x more expensive per GB than HDD storage across the variety of drives sold by industry hardware vendors in 2016. Because of this, it is important to discern which form of storage is being offered by a web hosting company when comparing account plans, and to favor SSD storage over HDDs for any web application requiring a high performance environment. There is a lot of variation between companies in the web hosting industry currently, with some web hosts offering SSD storage standard on all accounts, some companies using SSDs for MySQL database support with HDDs in RAID arrays deployed for serving website files, and some companies not offering SSD storage at all on their data center hardware.
This image shows a rackmount solid state storage drive (SSD) unit manufactured for web hosting that uses DDR RAM for file storage instead of a traditional hard disk drive. The RamSan-400 offers 3 GB per second data bandwidth speeds, with 100x faster response times and support for 100x more simultaneous users than a comparable hard disk drive with the same storage capability.
Otherwise, the most common storage method being used in web hosting currently are RAID systems which allow a server to access arrays of HDDs or SSDs with much higher storage capacities than available on a single drive. RAID arrays contain multiple storage drives that are used to mirror data in duplicate copies on a server. For example, in RAID-1 systems, two copies of website data are available for access by multi-threaded, multi-core CPU processors or for use as backups of site data in case of failure of one drive. In RAID-5 systems, parity is mirrored over three disks for increased security. RAID-6 uses double-distributed parity and requires a minimum of four storage drives. RAID 10 or RAID 1+0 combines the functionality of RAID 1 data mirroring with the direct data access procedures of RAID 0. In summary, the use of RAID storage arrays in web hosting guarantees that client data loss is an exceedingly rare occurrence as a result of storage drive failure in a data center. Some companies may also use additional off-site or external SCSI-based data backup procedures for an even higher level of data security in client operations, but this is generally more common in enterprise IT data centers than in web hosting.
STACK SOFTWARE
After the basic fundamentals of web server hardware are introduced, the technical details of the software that is used in web hosting can be understood in the wider context of data center operations. The current practice in web development and systems administration involves the conceptualization of web server software as a stack, due to the manner in which the different programs operate in layers on top of the same underlying computer hardware and networking technology. Stack software begins with the operating system, of which Linux and Windows are most common, but may also include FreeBSD, UNIX, or enterprise software. The next layer is the web server framework that provides support for all of the internet protocols used by domain names, HTTP transfers, FTP, and email. Most Linux and Windows servers use Apache HTTP Server software for this, which was originally released in 1995. On top of this layer, systems administrators install support for databases and programming languages like MySQL and PHP. From these combinations, web server stack software is frequently abbreviated as LAMP, WAMP, or LEMP. Nginx was released in 2004 and is a reverse proxy server that replaces Apache with load balancing and advanced caching features that allow it to scale to meet higher levels of web traffic.
LAMP
The LAMP stack includes a Linux operating system, Apache HTTP Server software, the MySQL database framework, along with the combination of the PHP, Python, and Perl programming languages. Most web servers operate on this standard and it is the preferred platform for open source web development. LAMP may include any one of the numerous Linux operating systems as the base installation, as Apache, MySQL, and PHP will all operate in the same manner on each. There a wide number of variants of the LAMP stack and many web hosting companies develop their own unique version as a “Platform as a Service” (PaaS) or “Infrastructure as a Service” (IaaS) business model when offering hosting plans.
• WAMP
The WAMP stack includes Windows Server software as the OS, an installation of the Apache HTTP Server package, MySQL database support, along with the PHP, Python, and Perl programming languages. Alternatively, the use of MSSQL databases in Windows development can be considered part of this stack. The WAMP stack is popular in enterprise IT and corporate web development, due to the requirements of integration with Microsoft software across multiple departments in a company or the use of legacy systems in operations. WIMP is another version similar to WAMP stack with IIS replacing Apache as the web server. Windows Server 2016 is the most recent version of the operating system.
LEMP
The LEMP (or LNMP) stack includes the replacement of Apache HTTP Server with Nginx, and is one of the fastest growing platform standards in web development. Nginx relates particularly to cloud computing and big data, as it was originally developed to address the problem with Apache of supporting more than 10,000 simultaneous users on a website. As this problem effects only the largest websites by traffic on the web, it is more common as a custom solution implemented by the most popular websites and media companies to support their user community requirements. For example, newspapers, popular blogs, or social networks can use Nginx to scale more efficiently on server hardware to meet traffic spikes than possible using Apache. Nginx is also free to use and published under an open source license, with Igor Sysoev the inventor and lead developer of the project.
This graphic shows the various layers of the LAMP stack and how they relate to web server hardware in serving files and documents over internet protocols.
DATA CENTER
To complete the general overview of the use of web servers in web hosting, it is required to show how the hardware and software are positioned in a data center environment. Technically almost any computer device can be configured to function as a web server. However, just as web server hardware has optimized features that are different from desktop computers or laptops, and the operating system for web servers, including the layers of stack software that are added for web development and online communication, are all specifically designed for internet publishing and network file transfer protocol requirements, so also the data center must be considered as a specialized environment with particular architectural and infrastructure design requirements that are implemented to meet the needs of the web hosting industry. Primarily these requirements involve optimizing the performance of web servers for the purpose of web publishing, network file transfer, online communication, and ecommerce.
Fiber Optic Bandwidth
The primary aspect that makes data centers unique is their connection to the “internet backbone” through fiber optic connections provided by telecommunication companies. Most web hosting companies contract with multiple service providers to have more than one connection available in case of systems failure. The high-speed bandwidth facilities offered by these connections is much faster than that available to home computers through cable broadband, mobile 3G/4G standards, wifi, or dial-up connections. By connecting networks of web servers to the internet through fiber optic cables, web hosting companies provide a unique utility service that is fundamental to web publishing.
Systems Administration
On the most basic level, web hosting companies must manage the hardware and software requirements of web servers which requires skilled systems administration. This means buying and installing the hardware in the data center, maintaining the equipment, making administrative choices on the operating system and platform software to be deployed, as well as managing the operation of the facilities and applying regular security updates. Along with this there are business model aspects such as brand identity, sales & marketing, customer relations, and technical support services for clients. Some web hosting companies also employ programmers to innovate in platform software.
Web Security
Because many customers trust their website data to web hosting companies, and hacking is a common part of the internet, web security is another fundamental that is essential to managing server networks. This can include configuring firewalls, monitoring network traffic, combating spam, managing DDoS attacks, blacklisting IP addresses from malicious users, applying security patches to operating systems installations and server extension platforms, or physical measures like keeping the data center premises secure from intruders. Because of the level of malicious activity present on the web, as well as the sophistication of attacks, and the value of hosted client website data, most web hosting companies must dedicate significant resources to this aspect of web server network management.
What to Look for in a Web Server
Having completed the basic introduction to web servers by looking at the hardware components, software stack, and data center environment, there are a few main points that can be summarized and used as a means to evaluate competitive web hosting services and plans when making decisions for web publishing or ecommerce. Some of these are:
Benchmark Performance of the Hardware
Benchmark testing of computer hardware is the best means of evaluating a web server, with numerous software tools and review sites available online to assist with the process. However, while it is easy to document what hardware is being provided for a dedicated server plan available through a web hosting company, it is not always equally simple to accurately benchmark the underlying hardware used on shared hosting and VPS plans. Similarly, other factors relating to the data center environment, such as the DNS server or the amount of resources allocated to a shared web hosting account, can also affect website performance. It is also not feasible for most individuals to sign-up for a web hosting account at every company in order to benchmark server performance on shared hosting plans. Because of this, the best recommendation is to research professional benchmark tests in order to compare service providers within the web hosting industry, balancing different opinions with verified hardware reviews.
Use of SSD Storage on Web Hosting Plans
As demonstrated in the benchmark test information provided above, the use of solid state drives (SSDs) in web hosting is one of the most important factors in improving website performance, which includes page load times and data transfer speeds. Most web hosting companies that offer SSDs on their services prominently advertise the feature in their sales & marketing promotions. Because the speed that web pages load at has become a primary aspect of Google’s PageRank algorithms, the use of SSDs in web hosting can also relate to SEO. Most business and ecommerce websites, as well as media publications and blogs, demand the best performance from a web server to support CMS scripts and database-driven content. In order to attain this, start with a web hosting account that is based on SSD storage.
The Uptime Record of the Hosting Company
Because most web hosting companies use multiple fiber optic providers for connection of their web servers to the internet, and nearly all promise a 99.9x% uptime guarantee, there is not any real reason for websites to go offline. If this happens frequently with a web hosting company data center, it is usually symptomatic of deeper problems or issues within the enterprise that makes for a reason to avoid the service in favor of other options. Because website owners are trusting their data, which includes customer private information, with a web hosting company, any group that advertises a 99.99% uptime guarantee but does not maintain their services up to the standard or who misleads in advertising over the issue without honoring the pledge is generally better off avoided as a service provider in favor of one of the many other upstanding, innovative, and ethical companies in the industry.
High Performance Platform Optimization
With over $50 billion in web server hardware sales and over $36 billion in revenue generated by web hosting internationally in 2016, there are a lot of different options, plans, and service providers to choose from in the industry. Most web hosting customers are simply ordering a fraction of resources of made available on a single server at $2.50 to $10 per month to keep their websites online. Because of this it can be recommended to look for “Platform as a Service” packages from companies that are actively innovating in cloud computing and web server software in order to get the best performance on services received for the cost invested. On a practical level, if a company is investing millions of dollars in time and resources on their platform development, or serving the hosting needs of the most demanding web applications in the marketplace at a high level, then making these same services available on the consumer level at a price equivalent to a few cups of coffee at Starbucks… this can be said to be a good deal, made possible by the unique way that software platforms can be easily replicated and reproduced digitally on web servers. In web hosting it is important to recognize which companies are doing the most important platform innovation in cloud computing and then take advantage of the tools through the purchase of “Platform as a Service” offerings, which will typically have a better hardware basis as well.
The Version of Software Extensions Installed
Web developers or programmers who use many web hosting services will quickly notice that while many plans offer the same services at equivalent prices there is actually a lot of variance between the different companies in the support for different standards related to programming languages, database frameworks, and other server extensions. While this may not matter for many website applications, for support of the latest web standards, or the newest versions of modules in popular content management systems, it can be very important. Therefore, it is recommended to pay close attention and do a detailed analysis of the version of the software extensions installed on a web server or hosting plan offered by the various companies. For example, most web hosting plans will support PHP, but the difference between PHP 5.4, 5.6, and 7.0 can be critical in various aspects of web development. Most platform extensions have similar differences, and web hosting companies that consistently lead in implementing advance support of the latest web standards are to be preferred in contracts over those who do not.
Network Security & Systems Administration
Network security and systems administration is fairly standardized across the web hosting industry, for example where almost all companies will be using the same operating systems, Apache server software, programming language extensions, and databases frameworks. Because systems administration and security updates takes place behind the scenes, in the data center, and generally involves anonymous technicians, there is no good way to verify or benchmark these services in web hosting companies other than their previous service records. Often times, the issues related to platform software exploits or release of security patches are out of the hands and scope of operations of the web hosting companies completely. Extensive use of proprietary code in building a custom platform for web hosting also requires expert testing for potential security issues. Open source code is not inherently more secure than proprietary code and vice versa. Therefore, the best recommendation with reference to network security and systems administration in web hosting is to look for transparency in operations, with all platform software used by a company well documented and published for reference on the account plans. Otherwise, the service record of the company itself is only a general guide with no guarantee of future service quality of operations.
Cost of the Resources Provided vs. Competitors
Since most of the web hosting companies are using the same hardware from the same manufacturers, and the software used in web hosting is also standardized, available from third-party development companies and open source projects, the main issue distinguishing the different web server plans provided by the various companies often comes down to a cost-value analysis. While the determination of this often requires reading the fine print on web hosting plans and researching the underlying hardware used by the different companies in providing services, doing so can lead to an accurate judgment as to which company or web hosting plan is offering the best prices or including the most platform features in relation to the relative costs of the services. With this it is not always the lowest overall cost that wins, but the provision of the most valuable web hosting and web development services in a package in relation to the cost of other comparable plans that is most determinative.