File hosting service

Most online file storage services offer space on a per-gigabyte basis, and sometimes include a bandwidth cost component as well. Usually these will be charged monthly or yearly. Some companies do offer the service for free, relying on advertising revenue. Some hosting services do not place any limit on how much space your account can consume. Some services require a software download which makes files only available on computers which have that software installed, others allow users to retrieve files through any web browser. With the increased inbox space offered by webmail services, many users have started using their webmail service as an online drive. Some sites offer free unlimited file storage but have a limit on the file size.
Increasingly, organizations are recognizing the benefits of co-locating their mission-critical equipment within a data centre. Colocation is becoming increasingly popular because of the time and cost savings a company can realize as a result of using shared data centre infrastructure. Significant benefits of scale (large power and mechanical systems) result in large colocation facilities, typically 5,000-10,000 m² (50,000 to 100,000 square feet). With IT and communications facilities in safe, secure hands, telecommunications, Internet, ASP and content providers, as well as enterprises, enjoy less latency and the freedom to focus on their core business.
Additionally, customers reduce their traffic back-haul costs and free up their internal networks for other uses. Moreover, by outsourcing network traffic to a colocation service provider with greater bandwidth capacity, web site access speeds should improve considerably.
Major types of colocation customers are:
Web commerce companies, who use the facilities for a safe environment and cost-effective, redundant connections to the Internet
Major enterprises, who use the facility for disaster avoidance, offsite data backup and business continuity
Telecommunication companies, who use the facilities to interexchange traffic with other telecommunications companies and access to potential clients
Most network access point facilities provide colocation.

the year of the LAN”.

The development and proliferation of CP/M-based personal computers from the late

1970s and then DOS-based personal computers from 1981 meant that a single site

began to have dozens or even hundreds of computers. The initial attraction of

networking these was generally to share disk space and laser printers, which were

both very expensive at the time. There was much enthusiasm for the concept and for

several years, from about 1983 onward, computer industry pundits would regularly

declare the coming year to be “the year of the LAN”.

In practice, the concept was marred by proliferation of incompatible physical Layer

and network protocol implementations, and a plethora of methods of sharing

resources. Typically, each vendor would have its own type of network card, cabling,

protocol, and network operating system. A solution appeared with the advent of

Novell NetWare which provided even-handed support for dozens of competing

card/cable types, and a much more sophisticated operating system than most of its

competitors. Netware dominated[8] the personal computer LAN business from early

after its introduction in 1983 until the mid 1990s when Microsoft introduced Windows

NT Advanced Server and Windows for Workgroups.

Of the competitors to NetWare, only Banyan Vines had comparable technical

strengths, but Banyan never gained a secure base. Microsoft and 3Com worked

together to create a simple network operating system which formed the base of

3Com's 3+Share, Microsoft's LAN Manager and IBM's LAN Server. None of these were

particularly successful, Unix computer workstations from vendors such as Sun

Microsystems, Hewlett-Packard, Silicon Graphics, Intergraph, NeXT and Apollo were

using TCP/IP based networking. Although this market segment is now much reduced,

the technologies developed in this area continue to be influential on the Internet and

in both Linux and Apple Mac OS X networking—and the TCP/IP protocol has now

almost completely replaced IPX, AppleTalk, NBF and other protocols used by the

early PC LANs.

computing, the Global File System (GFS)

In computing, the Global File System (GFS) is a shared disk file system for Linux

computer clusters.

GFS and GFS2 differ from distributed file systems (such as AFS, Coda, or InterMezzo)

because they allow all nodes to have direct concurrent access to the same shared

block storage. In addition, GFS or GFS2 can also be used as a local filesystem.

GFS has no disconnected operating-mode, and no client or server roles. All nodes in

a GFS cluster function as peers. Using GFS in a cluster requires hardware to allow

access to the shared storage, and a lock manager to control access to the storage.

The lock manager is a separate module and thus GFS and GFS2 can use the

Distributed Lock Manager (DLM) for cluster configurations and the "nolock" lock

manager for local filesystems. Older versions of GFS also support GULM, a server

based lock manager which implements redundancy via failover.

A Red Hat cluster suite when configured for high availability

A Red Hat cluster suite when configured for high availability attempts to ensure

service availability by monitoring other nodes of the cluster. All nodes of the cluster

must agree on their configuration and shared services state before the cluster is

considered Quorate and services are able to be started.

The primary form of communicating node status is via a network device (commonly

Ethernet), although in the case of possible network failure, quorum can be decided

through secondary methods such as shared storage or multicast.

Software services, filesystems and network status can be monitored and controlled by

the cluster suite, services and resources can be failed over to other network nodes in

case of failure.

The Cluster suite forcibly terminates a cluster node's access to services or resources

to ensure the node and data is in a known state. The node is terminated by removing

power or access to the shared storage.

Service locking and control is guaranteed through fencing and STONITH, more recent

versions of Red Hat use a distributed lock manager (DLM), to allow fine grained

locking and no single point of failure. Earlier versions of the cluster suite relied on

GULM (Grand Unified Lock Manager) which could be clustered, but still presented a

point of failure) if the nodes acting as gulm servers were to fail. GULM as a locking

manager is available but deprecated in Red Hat Cluster Suite 5.

Compute clusters basics

Compute clusters

Often clusters are used primarily for computational purposes, rather than handling

IO-oriented operations such as web service or databases. For instance, a cluster

might support computational simulations of weather or vehicle crashes. The primary

distinction within compute clusters is how tightly-coupled the individual nodes are.

For instance, a single compute job may require frequent communication among

nodes - this implies that the cluster shares a dedicated network, is densely located,

and probably has homogenous nodes. This cluster design is usually referred to as

Beowulf Cluster. The other extreme is where a compute job uses one or few nodes,

and needs little or no inter-node communication. This latter category is sometimes

called "Grid" computing. Tightly-coupled compute clusters are designed for work that

might traditionally have been called "supercomputing". Middleware such as MPI

(Message Passing Interface) or PVM (Parallel Virtual Machine) permits compute

clustering programs to be portable to a wide variety of clusters.

Grid computing basics

Grids are usually computer clusters, but more focused on throughput like a

computing utility rather than running fewer, tightly-coupled jobs. Often, grids will

incorporate heterogeneous collections of computers, possibly distributed

geographically, sometimes administered by unrelated organizations.

Grid computing is optimized for workloads which consist of many independent jobs

or packets of work, which do not have to share data between the jobs during the

computation process. Grids serve to manage the allocation of jobs to computers

which will perform the work independently of the rest of the grid cluster. Resources

such as storage may be shared by all the nodes, but intermediate results of one job

do not affect other jobs in progress on other nodes of the grid.

An example of a very large grid is the Folding@home project. It is analyzing data that

is used by researchers to find cures for diseases such as Alzheimer's and cancer.

Another large project is the SETI@home project, which may be the largest distributed

grid in existence. It uses approximately three million home computers all over the

world to analyze data from the Arecibo Observatory radiotelescope, searching for

evidence of extraterrestrial intelligence. In both of these cases, there is no inter-node

communication or shared storage. Individual nodes connect to a main, central

location to retrieve a small processing job. They then perform the computation and

return the result to the central server. In the case of the @home projects, the software

is generally run when the computer is otherwise idle. U of C Berkley has developed an

open source application BOINC to allow individual users to contribute to the above

and other projects such as lhc@home (Large Hadron Collider) from a single manager

which can then be set to allocate a percentage of idle time to each of the projects a

node is signed up for. The Software can be downloaded and a project list can be

found here BOINC

The grid setup means that the nodes can take however many jobs they are able to

process in one session and then return the results and acquire a new job from a

central project server.

The history of cluster computing

The history of cluster computing is best captured by a footnote in Greg Pfister's In Search of Clusters: “Virtually every press release from DEC mentioning clusters says ‘DEC, who invented clusters…’. IBM did not invent them either. Customers invented clusters, as soon as they could not fit all their work on one computer, or needed a backup. The date of the first is unknown, but it would be surprising if it was not in the 1960s, or even late 1950s.”[4]

The formal engineering basis of cluster computing as a means of doing parallel work of any sort was arguably invented by Gene Amdahl of IBM, who in 1967 published what has come to be regarded as the seminal paper on parallel processing: Amdahl's Law. Amdahl's Law describes mathematically the speedup one can expect from parallelizing any given otherwise serially performed task on a parallel architecture. This article defined the engineering basis for both multiprocessor computing and cluster computing, where the primary differentiator is whether or not the interprocessor communications are supported "inside" the computer (on for example a customized internal communications bus or network) or "outside" the computer on a commodity network.

Consequently the history of early computer clusters is more or less directly tied into the history of early networks, as one of the primary motivation for the development of a network was to link computing resources, creating a de facto computer cluster. Packet switching networks were conceptually invented by the RAND corporation in 1962. Using the concept of a packet switched network, the ARPANET project succeeded in creating in 1969 what was arguably the world's first commodity-network based computer cluster by linking four different computer centers (each of which was something of a "cluster" in its own right, but probably not a commodity cluster). The ARPANET project grew into the Internet—which can be thought of as "the mother of all computer clusters" (as the union of nearly all of the compute resources, including clusters, that happen to be connected). It also established the paradigm in use by all computer clusters in the world today—the use of packet-switched networks to perform interprocessor communications between processor (sets) located in otherwise disconnected frames.

The development of customer-built and research clusters proceeded hand in hand with that of both networks and the Unix operating system from the early 1970s, as both TCP/IP and the Xerox PARC project created and formalized protocols for network-based communications. The Hydra operating system was built for a cluster of DEC PDP-11 minicomputers called C.mmp at C-MU in 1971. However, it was not until circa 1983 that the protocols and tools for easily doing remote job distribution and file sharing were defined (largely within the context of BSD Unix, as implemented by Sun Microsystems) and hence became generally available commercially, along with a shared filesystem.

The first commercial clustering product was ARCnet, developed by Datapoint in 1977. ARCnet was not a commercial success and clustering per se did not really take off until DEC released their VAXcluster product in 1984 for the VAX/VMS operating system. The ARCnet and VAXcluster products not only supported parallel computing, but also shared file systems and peripheral devices. The idea was to provide the advantages of parallel processing, while maintaining data reliability and uniqueness. VAXcluster, now VMScluster, is still available on OpenVMS systems from HP running on Alpha and Itanium systems.

Two other noteworthy early commercial clusters were the Tandem Himalaya (a circa 1994 high-availability product) and the IBM S/390 Parallel Sysplex (also circa 1994, primarily for business use).

No history of commodity computer clusters would be complete without noting the pivotal role played by the development of Parallel Virtual Machine (PVM) software in 1989. This open source software based on TCP/IP communications enabled the instant creation of a virtual supercomputer—a high performance compute cluster—made out of any TCP/IP connected systems. Free form heterogeneous clusters built on top of this model rapidly achieved total throughput in FLOPS that greatly exceeded that available even with the most expensive "big iron" supercomputers. PVM and the advent of inexpensive networked PCs led, in 1993, to a NASA project to build supercomputers out of commodity clusters. In 1995 the invention of the "beowulf"-style cluster—a compute cluster built on top of a commodity network for the specific purpose of "being a supercomputer" capable of performing tightly coupled parallel HPC computations. This in turn spurred the independent development of Grid computing as a named entity, although Grid-style clustering had been around at least as long as the Unix operating system and the Arpanet, whether or not it, or the clusters that used it, were named.

Reseller hosting :host websites on behalf of third parties

Reseller hosting is a form of web hosting wherein the account owner has the ability to use his/her allotted hard drive space and bandwidth to host websites on behalf of third parties. The reseller purchases the host's services wholesale and then sells them to customers for a profit. A certain portion of hard drive and bandwidth is allocated to the reseller account. The reseller may rent a dedicated server from a hosting company, or resell shared hosting services. In the latter case, the reseller is simply given the permission to sell a certain amount of disk space and bandwidth to his own customers without renting a server from a web hosting company he signed for a reseller account with.

The typical web hosting reseller might be a web design firm, web developer or systems integrator who offers web hosting as an add-on service. Reseller hosting is also an inexpensive way for web hosting entrepreneurs to start a company. Most reseller hosting plans allow resellers to create their own service plans and choose their own pricing structure. In many cases, resellers are able to establish their own branding via customized control panels and name servers.

Reseller hosting does not require extensive knowledge of the technical aspects of web hosting. Usually, the data center operator is responsible for maintaining network infrastructure and hardware, and the dedicated server owner configures, secures, and updates the server. A reseller is responsible for interfacing with his/her own customer base, but any hardware, software and connectivity problems are typically forwarded to the server provider from whom the reseller plan was purchased. It should be noted that being a profitable reseller firm usually involves extensive advertising to get customers. While the monthly fees with major hosts are only a few dollars a month, it's a low margin business, and resellers must devote large advertising budgets to compete with established competitors. However, web hosting is one of the biggest online businesses, because every website needs hosting.

Resellers can set up and manage customer accounts via a web interface, usually point and click "Control Panels."

Online backup services and uses

The amount of data used by businesses has increased exponentially, in the past five years alone.
Corporate scandals, international unrest and glaring security flaws in computer operating systems
and software applications have resulted in intense and detailed analysis of data, as it enters and
leaves an individual’s PC/enterprise computer.

With the proliferation of the Internet, data sensitive resources like computers cannot be viewed in
isolation – they have become supply chains in themselves. This supply chain has now gotten
integrated with the next level of data movement of data backups - from end user’s
(individual/enterprise) PC to online backup locations, located at an offsite location in a different
geography.

It is this data movement – from the end user’s PC to the online backup location that will be
the focus of this white paper.

Service scope

Service scope

The scope of hosting services varies widely. The most basic is web page and

small-scale file hosting, where files can be uploaded via File Transfer Protocol (FTP)

or a Web interface. The files are usually delivered to the Web "as is" or with little

processing. Many Internet service providers (ISPs) offer this service free to their

subscribers. People can also obtain Web page hosting from other, alternative service

providers. Personal web site hosting is typically free, advertisement-sponsored, or

cheap. Business web site hosting often has a higher expense.

Single page hosting is generally sufficient only for personal web pages. A complex

site calls for a more comprehensive package that provides database support and

application development platforms (e.g. PHP, Java, Ruby on Rails, ColdFusion, and

ASP.NET). These facilities allow the customers to write or install scripts for

applications like forums and content management. For e-commerce, SSL is also

highly recommended.

The host may also provide an interface or control panel for managing the Web server

and installing scripts as well as other services like e-mail. Some hosts specialize in

certain software or services (e.g. e-commerce). They are commonly used by larger

companies to outsource network infrastructure to a hosting company.

A shared web hosting service or virtual hosting service or derive host

The hosting service must include system administration since it is shared by many users; this is a benefit for users who do not want to deal with it, but a hindrance to power users who want more control. In general shared hosting will be inappropriate for users who require extensive software development outside what the hosting provider supports. Almost all applications intended to be on a standard web server work fine with a shared web hosting service. But on the other hand, shared hosting is cheaper than other types of hosting such as dedicated server hosting. Shared hosting usually has usage limits and most hosting providers have extensive reliability features in place. [1]

Shared hosting typically uses a web-based control panel system, such as cPanel, Ensim, DirectAdmin, Plesk, InterWorx, H-Sphere or one of many other control panel products. Most of the large hosting companies use their own custom developed control panel. Control panels and web interfaces can cause controversy however, since web hosting companies sometimes sell the right to use their control panel system to others. Attempting to recreate the functionality of a specific control panel is common, which leads to many lawsuits over patent infringement.[2]

In shared hosting, the provider is generally responsible for managing servers, installing server software, security updates, technical support, and other aspects of the service. Most servers are based on the Linux operating system and LAMP (software bundle), which is driven by the low cost of open source software. But some providers offer Microsoft Windows-based or FreeBSD-based solutions. For example, the Plesk and Ensim control panels are both available for two operating systems, Linux and Windows. Versions for either OS have very similar interfaces and functionality, with the exception of OS-specific differences (for example: ASP.NET, SQL Server and Access support under Windows; MySQL under Linux).

There are thousands of shared hosting providers in the United States alone. They range from mom-and-pop shops and small design firms to multi-million-dollar providers with hundreds of thousands of customers. A large portion of the shared web hosting market is driven through pay per click (PPC) advertising or Affiliate programs.

Shared web hosting can also be done privately by sharing the cost of running a server in a colocation centre; this is called cooperative hosting.

A system administrator, or sysadmin systems administrator

A system administrator, systems administrator, or sysadmin, is a person employed to

maintain and operate a computer system and/or network. System administrators may

be members of an information technology department.

The duties of a system administrator are wide-ranging, and vary widely from one

organization to another. Sysadmins are usually charged with installing, supporting,

and maintaining servers or other computer systems, and planning for and responding

to service outages and other problems. Other duties may include scripting or light

programming, project management for systems-related projects, supervising or

training computer operators, and being the consultant for computer problems beyond

the knowledge of technical support staff. A system administrator must demonstrate a

blend of technical skills and responsibility in order to perform their job well.

FFmpeg hosting--assortment of software

FFmpeg hosting is a term that is used to refer to any "assortment of software which is

available free, which helps in recording, converting and streaming a digital video or

an audio", and to those domain registrars and web hosting companies which provide

the above assortment of software to video hosting services. It is known as FFmpeg

hosting due to the usage by several video hosting services of the FFmpeg software

library in the server-side conversion of files with variously-encoded video and audio

formats into a single preferred video or audio format that is both playable from the

video hosting service and embeddable into any offsite webpage. As of 2010, the

preferred format for the presentation of converted video is the .mp4 format.

Typically, most hosting infrastructures are based on the paradigm of using a single

physical machine to host multiple hosted services, including web, database, email,

FTP and others. A single physical machine is not only a single point of failure, but

also has finite capacity for traffic, that in practice can be troublesome for a busy

website or for a website that is experiencing transient bursts in traffic.

By clustering services across multiple hardware machines, and using load balancing

you can eliminate single points of failure increasing availability of your website and

other web services beyond that of ordinary single server hosting. A single server can

require periodic reboots for software upgrades and the like, whereas in a clustered

platform you can stagger the restarts such that the service is still available whilst still

upgrading all necessary machines in the cluster.

Clustered hosting is similar to cloud hosting, in that the resources of many machines

are available for a website to utilize on demand, making scalability a large advantage

to a clustered hosting solution.

Clustered hosting- is a Spreading Hosting

Clustered hosting is a type of web hosting that spreads the load of hosting across

multiple physical machines ("nodes"), increasing availability and decreasing the

chances of one service (for example FTP, or email) affecting another - for example

web or database (e.g. MySQL). Many large websites run on clustered hosting

solutions, for example, large discussion forums will tend to run using multiple

front-end webservers with multiple back-end database servers.

Typically, most hosting infrastructures are based on the paradigm of using a single

physical machine to host multiple hosted services, including web, database, email,

FTP and others. A single physical machine is not only a single point of failure, but

also has finite capacity for traffic, that in practice can be troublesome for a busy

website or for a website that is experiencing transient bursts in traffic.

By clustering services across multiple hardware machines, and using load balancing

you can eliminate single points of failure increasing availability of your website and

other web services beyond that of ordinary single server hosting. A single server can

require periodic reboots for software upgrades and the like, whereas in a clustered

platform you can stagger the restarts such that the service is still available whilst still

upgrading all necessary machines in the cluster.

Clustered hosting is similar to cloud hosting, in that the resources of many machines

are available for a website to utilize on demand, making scalability a large advantage

to a clustered hosting solution.

mail hosting services on internet

E-mail hosting services usually offer premium e-mail at a cost as opposed to advertising

supported free e-mail or free webmail. E-mail hosting services thus differ from typical

end-user e-mail providers such as webmail sites. They cater mostly to demanding e-mail

users and Small and Mid Size (SME) businesses, while larger enterprises usually run their

own e-mail hosting service. E-mail hosting providers allow for premium e-mail services along

with custom configurations and large number of accounts. In addition, hosting providers

manage user's own domain name, including any e-mail authentication scheme that the

domain owner wishes to enforce in order to convey the meaning that using a specific domain

name identifies and qualifies e-mail senders.

Most e-mail hosting providers offer advanced premium e-mail solutions hosted on dedicated

custom e-mail platforms. The technology and offerings of different e-mail hosting providers

can therefore vary with different needs. E-mail offered by most webhosting companies is

usually more basic standardized POP3 based e-mail and webmail based on open source

webmail applications like Horde or SquirrelMail. Almost all webhosting providers offer

standard basic e-mail while not all e-mail hosting providers offer webhosting.