|
| |
A dedicated hosting service, dedicated server, or managed hosting service is
a type of Internet hosting where 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. However,
Microsoft requires additional license fees on all their products, thus
increasing the monthly cost of a dedicated server running a Windows operating
system. 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 up2date. 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 the operating systems above 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 & 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 (bps). 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. The
measurement can be compared to mph (Miles Per Hour), or how fast something
travels. Line Speed is measured using bits per second, kilobits per second,
megabits per second, and 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 coming from the server, measured in
bytes. Measurement between providers varies and includes one of the following
equations:
Method 1: IN TRAFFIC + OUT TRAFFIC = TOTAL TRANSFER
Method 2: IN TRAFFIC = TOTAL TRANSFER
Method 3: OUT TRAFFIC = TOTAL TRANSFER
One of the reasons people choose 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 SLA (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 mostly likely 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
Technical Support
Firewall Services
Anti-Virus Updates
Security Audits
Backups and Restoration
Disaster Recovery
DNS Hosting
Load Balancing
Database Administration
Performance Tuning
DDOS Protection and Mitigation
Software Installation, Configuration
Intrusion Detection
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,
and eggdrops (see "Limitations" below). Linux and Windows use different software
for security protection. Below is a list of security software and services based
on the operating system installed on a dedicated server:
Linux Dedicated Servers
Port Sentry
Connect scans
SYN Scans
FIN Scans
NULL Scans
XMAS Scans
FULL-XMAS Scan
UDP Scan
Windows Dedicated Servers
Trend Micro
Software
Providers often bill for dedicated servers on a fixed monthly price to include
specific software packages. Over the years, software vendors realized the
significant market opportunity to bundle their software with dedicated servers.
They have since started introducing pricing models that allow dedicated hosting
providers the ability to purchase and resell software based on reduced monthly
fees.
Microsoft offers software licenses through a program called the Service Provider
License Agreement. The SPLA model provides use of Microsoft products through a
monthly user or processor based fee. SPLA software includes the Windows
Operating System, Microsoft SQL Server, Microsoft Exchange Server, Microsoft
SharePoint and shoutcast hosting, and many other server based products.
Dedicated Server Providers usually offer the ability to select the software you
want installed on a dedicated server. Depending on the overall usage of the
server, this will include your choice of operating system, database, and
specific applications. Servers can be customized and tailored specific to the
customer’s needs and requirements.
Other software applications available are specialized web hosting specific
programs called control panels. Control panel software is an all inclusive set
of software applications, server applications, and automation tools that can be
installed on a dedicated server. Control panels include integration into web
servers, database applications, programming languages, application deployment,
server administration tasks, and include the ability to automate tasks via a web
based front end.
Most dedicated servers are packaged with a control panel. Control panels are
often confused with management tools, but these control panels are actually web
based automation tools created to help automate the process of web site creation
and server management. Control panels should not be confused with a full server
management solution by a dedicated hosting provider.
Limitations
Many providers do not allow IRC (eggdrops, clients or daemons). This is due to
rogue IRC users triggering DDoS attacks against the provider, which may
overwhelm their networks, lowering service quality for all customers.
Adult content is disallowed by many providers as it may either be of
questionable legality or consume large amounts of bandwidth.
Spam is usually prohibited by the provider's Acceptable Use Policy.
Extra features
Useful features for dedicated servers may be included, or cost additional
monthly fees:
Serial Console or KVM/IP - this is used to gain access to a server if for some
reason the user is unable to get in via normal means (e.g. ssh), and permits a
server to be recovered from boot-time configuration faults, such as filesystem
recovery.
Automated restore of OS - an automated system can be used to restore the server
to its original configuration.
Remote Backup Space - ssh/FTP space to backup data stored on the server.
ColdFusion (MX) - ColdFusion is the rapid server scripting environment for
creating Rich Internet Applications.
SQL Server - Server dedicated to hosting Microsoft SQL databases and typically
incur additional hosting fees.
Oracle - Server dedicated to hosting Oracle databases and typically incur
additional hosting fees.
| |
|
