Wednesday, December 9, 2009

Dedicated Webhosting

Dedicated hosting service

A dedicated hosting service, dedicated server, or managed hosting service is a type of Internet hosting in which the client leases an entire server not shared with anyone. This is more flexible than shared hosting, as organizations have full control over the server(s), including choice of operating system, hardware, etc. Server administration can usually be provided by the hosting company as an add-on service. In some cases a dedicated server can offer less overhead and a larger return on investment. Dedicated servers are most often housed in data centers, similar to colocation facilities, providing redundant power sources and HVAC systems. In contrast to colocation, the server hardware is owned by the provider and in some cases they will provide support for your operating system or applications.

Operating system support:

Availability, price and employee familiarity often determines which operating systems are offered on dedicated servers. Variations of Linux (open source operating systems) are often included at no charge to the customer. Commercial operating systems include Microsoft Windows Server, provided through a special program called Microsoft SPLA. Red Hat Enterprise is a commercial version of Linux offered to hosting providers on a monthly fee basis. The monthly fee provides OS updates through the Red Hat Network using an application called yum. Other operating systems are available from the open source community at no charge. These include CentOS, Fedora Core, Debian, and many other Linux distributions or BSD systems FreeBSD, NetBSD, OpenBSD.

Support for any of these operating systems typically depends on the level of management offered with a particular dedicated server plan. Operating system support may include updates to the core system in order to acquire the latest security fixes, patches, and system-wide vulnerability resolutions. Updates to core operating systems include kernel upgrades, service packs, application updates, and security patches that keep server secure and safe. Operating system updates and support relieves the burden of server management from the dedicated server owner.

Bandwidth and connectivity:

Bandwidth refers to the data transfer rate or the amount of data that can be carried from one point to another in a given time period (usually a second) and is often represented in bits (of data) per second (bit/s). For example, visitors to your server, web site, or applications utilize bandwidth as the traffic moves from your server to the Internet and vice versa. Connectivity refers to the “access providers” that supply bandwidth, or data transfer rate, through various connection points across a network or footprint to one or multiple data centers where dedicated servers are housed.

Bandwidth measurements are defined (per telecom standards) as the following:


    * First – 95th (measured using average bits and speed of transfer)
    * Second – Unmetered (measured in speed or bits)
    * Third – Total Transfer (measured in bytes transferred)

95th Method: line speed, billed on the 95th percentile, average or peak usage, refers to the speed in which data flows from the server or device. Line speed is measured in bits per second (or kilobits per second, megabits per second or gigabits per second).

Unmetered Method: The second bandwidth measurement is unmetered service where providers cap or control the “top line” speed for a server. Top line speed in unmetered bandwidth is the total Mbit/s allocated to the server and configured on the switch level. For example, if you purchase 10 Mbit/s unmetered bandwidth, the top line speed would be 10 Mbit/s. 10 Mbit/s would result in the provider controlling the speed transfers take place while providing the ability for the dedicated server owner to not be charged with bandwidth overages. Unmetered bandwidth services usually incur an additional charge.

Total Transfer Method: Some providers will calculate the Total Transfer, the measurement of actual data leaving and arriving, measured in bytes. Measurement between providers varies, though it is either the total traffic in, the total traffic out, whichever is the greater or the sum of the two.

One of the reasons for choosing to outsource dedicated servers is the availability of high powered networks from multiple providers. As dedicated server providers utilize massive amounts of bandwidth, they are able to secure lower volume based pricing to include a multi-provider blend of bandwidth. To achieve the same type of network without a multi-provider blend of bandwidth, a large investment in core routers, long term contracts, and expensive monthly bills would need to be in place. The expenses needed to develop a network without a multi-provider blend of bandwidth does not make sense economically for hosting providers.

Many dedicated server providers include a service level agreement based on network uptime. Some dedicated server hosting providers offer a 100% uptime guarantee on their network. By securing multiple vendors for connectivity and using redundant hardware, providers are able to guarantee higher uptimes; usually between 99-100% uptime if they are a higher quality provider. One aspect of higher quality providers is they are most likely to be multi-homed across multiple quality uplink providers, which in turn, provides significant redundancy in the event one goes down in addition to potentially improved routes to destinations.

Bandwidth consumption over the last several years has shifted from a per megabit usage model to a per gigabyte usage model. Bandwidth was traditionally measured in line speed access that included the ability to purchase needed megabits at a given monthly cost. As the shared hosting model developed, the trend towards gigabyte or total bytes transferred, replaced the megabit line speed model so dedicated server providers started offering per gigabyte.

Prominent players in the dedicated server market offer large amounts of bandwidth ranging from 500 gigabytes to 3000 gigabytes using the “overselling” model. It is not uncommon for major players to provide dedicated servers with 1Terabyte (TB) of bandwidth or higher. Usage models based on the byte level measurement usually include a given amount of bandwidth with each server and a price per gigabyte after a certain threshold has been reached. Expect to pay additional fees for bandwidth overage usage. For example, if a dedicated server has been given 3000 gigabytes of bandwidth per month and the customer uses 5000 gigabytes of bandwidth within the billing period, the additional 2000 gigabytes of bandwidth will be invoiced as bandwidth overage. Each provider has a different model for billing. As of yet, no industry standards have been set.

Management

To date, no industry standards have been set to clearly define the management role of dedicated server providers. What this means is that each provider will use industry standard terms, but each provider will define them differently. For some dedicated server providers, fully managed is defined as having a web based control panel while other providers define it as having dedicated system engineers readily available to handle all server and network related functions of the dedicated server provider.

Server management can include some or all of the following:

    * Operating system updates
    * Application updates
    * Server monitoring
    * SNMP hardware monitoring
    * Application monitoring
    * Application management
    * Technical support
    * Firewall services
    * Antivirus updates
    * Security audits
    * DDoS protection and mitigation
    * Intrusion detection
    * Backups and restoration
    * Disaster recovery
    * DNS hosting service
    * Load balancing
    * Database administration
    * Performance tuning
    * Software installation and configuration
    * User management
    * Programming consultation

Dedicated hosting server providers define their level of management based on the services they provide. In comparison, fully managed could equal self managed from provider to provider.

Administrative maintenance of the operating system, often including upgrades, security patches, and sometimes even daemon updates are included. Differing levels of management may include adding users, domains, daemon configuration, or even custom programming.

Dedicated server hosting providers may provide the following types of server managed support:


    * Fully Managed - Includes monitoring, software updates, reboots, security patches and operating system upgrades. Customers are completely hands-off.
    * Managed - Includes medium level of management, monitoring, updates, and a limited amount of support. Customers may perform specific tasks.
    * Self Managed - Includes regular monitoring and some maintenance. Customers provide most operations and tasks on dedicated server.
    * Unmanaged - Little to no involvement from service provider. Customers provide all maintenance, upgrades, patches, and security.

Note: The provider will continue to maintain security on the network regardless of support level.



Security:

Dedicated hosting server providers utilize extreme security measures to ensure the safety of data stored on their network of servers. Providers will often deploy various software programs for scanning systems and networks for obtrusive invaders, spammers, hackers, and other harmful problems such as Trojans, worms, eggdrops and crashers (Sending multiple connections). Linux and Windows use different software for security protection

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