Archive for April 2014
CLOUD COMPUTING
Cloud computing is a type of computing that relies on sharing computing resources rather than having local servers or
personal devices to handle applications.
In cloud computing, the word cloud (also phrased as "the
cloud") is used as a metaphor for "the Internet,"
so the phrase cloud computing means "a type of Internet-based
computing," where different services — such
as servers, storage and applications —are delivered to an
organization's computers and devices through the Internet.
Cloud computing is comparable to grid computing,
a type of computing where unused processing cycles of all computers in a
network are harnesses to solve problems too intensive for any stand-alone
machine.
The world of the
cloud has lots of participants:
·
The
end user who doesn’t have to know anything about the underlying technology.
·
Business
management who needs to take responsibility for the governance of data or
services living in a cloud. Cloud service providers must provide a predictable
and guaranteed service level and security to all their constituents.
·
The
cloud service provider who is responsible for IT assets and maintenance.
Advantages of cloud computing
1. Worldwide
Access. Cloud computing
increases mobility, as you can access your documents from any device in any
part of the world. For businesses, this means that employees can work from home
or on business trips, without having to carry around documents. This increases
productivity and allows faster exchange of information. Employees can also work
on the same document without having to be in the same place.
2.
More
Storage. In the past,
memory was limited by the particular device in question. If you ran out of
memory, you would need a USB drive to backup your current device. Cloud
computing provides increased storage, so you won’t have to worry about running
out of space on your hard drive.
3.
Easy
Set-Up. You can set up
a cloud computing service in a matter of minutes. Adjusting your individual
settings, such as choosing a password or selecting which devices you want to
connect to the network, is similarly simple. After that, you can immediately
start using the resources, software, or information in question.
4.
Automatic
Updates. The cloud
computing provider is responsible for making sure that updates are available –
you just have to download them. This saves you time, and furthermore, you don’t
need to be an expert to update your device; the cloud computing provider will
automatically notify you and provide you with instructions.
5.
Reduced
Cost. Cloud computing
is often inexpensive. The software is already installed online, so you won’t
need to install it yourself. There are numerous cloud computing applications
available for free, such as Dropbox,
and increasing storage size and memory is affordable. If you need to pay for a
cloud computing service, it is paid for incrementally on a monthly or yearly
basis. By choosing a plan that has no contract, you can terminate your use of
the services at any time; therefore, you only pay for the services when you
need them
The working principle of cloud computing
The principle of
cloud computing is almost same with another computer, just the different of that is in cloud
computing, is coupled with another present computer. In regular computer, file from software when
we used is stored in hardisk or another storage media. But on computer clouds
if viewed from the side of the user, the files from software we use is in
another computer.
In other words we
are connected to multiple computers on a network server, but the data we store
it was in the data center or in center, so that not only we can open the file
that we save but computers or other users can open it and vice versa (Public).
Also in a lot of infrastructure servers that we can use and we only pay as
needed.
1. On-demand self-service. This means provisioning or de-provisioning computing resources as
needed in an automated fashion without human intervention. An analogy to this
is electricity as a utility where a consumer can turn on or off a switch
on-demand to use as much electricity as required.
2. Ubiquitous network access. This means that computing facilities can be accessed from anywhere
over the network using any sort of thin or thick clients (for example
smartphones, tablets, laptops, personal computers and so on).
3. Resource pooling. This means that computing resources are pooled to meet the demand
of the consumers so that resources (physical or virtual) can be dynamically
assigned, reassigned or de-allocated as per the requirement. Generally the
consumers are not aware of the exact location of computing resources. However,
they may be able to specify location (country, city, region and the like) for
their need. For example, I as a consumer might want to host my services with a
cloud provider that has cloud data centers within the boundaries of Australia.
4. Rapid elasticity. Cloud computing provides an illusion of infinite computing
resources to the users. In cloud models, resources can be elastically
provisioned or released according to demand. For example, my cloud-based online
services should be able to handle a sudden peak in traffic demand by expanding
the resources elastically. When the peak subsides, unnecessary resources can be
released automatically.
5. Measured service. This means that consumers only pay for the computing resources
they have used. This concept is similar to utilities like water or electricity.
SECURITY
Security. When using a cloud computing
service, you are essentially handing over your data to a third party. The fact
that the entity, as well as users from all over the world, are accessing the
same server can cause a security issue. Companies handling confidential
information might be particularly concerned about using cloud computing, as
data could possibly be harmed by viruses and other malware. That said, some
servers like Google Cloud Connect come with customizable spam filtering, email
encryption, and SSL enforcement for secure HTTPS access, among other
security measures.
The biggest question most
have with Cloud Computing is will it be Safe? The answer is “NO” Reason why is everything that Cloud Computing
is based on is mechanical, although it seems virtual. The Safety of the data
(information), is only as Safe as the will and determination of the individual
that wants to have at it.
THE
CONCEPT OF CLOUD COMPUTING
The first building block is the
infrastructure where the cloud will be implemented. Some people make the
assumption that environment should be virtualized, but as cloud is a way to
request resources in an on-demand way and if you have solutions to
provide on bare metal, then why not? The infrastructure will support the
different types of cloud (IaaS, PaaS, SaaS, BPaaS).
To be able to provide these
services you will need Operating System Services (OSS), which will be in charge
of deploying the requested service, and Business System Services (BSS), mainly
used to validate the request and create the invoice for the requested services.
Any metrics could be used to create the invoice (for example, number of users,
number of CPUs, memory, usage hours/month). It is very flexible and depends on
the service provider.
A cloud computing environment will
also need to provide interfaces and tools for the service creators and users.
This is the role of the Cloud Service Creator and Cloud Service Consumer
components.
Now,
let’s see how it works in reality.
Generally, you log in to a portal
(enterprise or public wise) and you order your services through the Cloud
Service Consumer. This service has been created by the cloud service provider
and can be a simple virtual machine (VM) based on an image, some network
components, an application service such as an WebApp environment and a service
such as MongoDB. It depends on the provider and type of resources and services.
The cloud provider will validate,
through the BSS, your request and if the validation is okay (credit card,
contract), it will provision the request through the OSS.
You
will receive, in one way or another, the credentials to access your requested
services and you will usually receive a monthly invoice for your consumption.
Reference :
http://12285-if-unsika.blogspot.com/2012/10/prinsip-kerja-cloud-computing-atau.html
permasalahan sistem terdistribusi baru
Banyak hal yang sering menjadi masalah pada pembangunan sebuah sistem terdisribusi, seperti masalah keamanan, aplikasi yang digunakan, kompleksitas dan lain lain
Sistem terdistribusi terdiri dari komputer otonom yang
bekerja sama untuk memberikan tampilan sistem yang satu kesatuan. keuntungan dari system ini ialah memberi
kemudahan untuk mengintegrasikan aplikasi yang berbeda berjalan pada komputer
yang berbeda ke dalam satu sistem. Keuntungan lain adalah ketika dirancang
dengan baik, skala sistem terdistribusi
akan mengikuti dengan ukuran jaringan yang mendasarinya. Namun system ini memiliki kekurangan seperti biaya perangkat lunak yang lebih kompleks,
penurunan kinerja, dan keamanan juga sering lemah. Namun demikian, ada minat
yang cukup besar di seluruh dunia dalam membangun dan memasang sistem
terdistribusi.
Sistem terdistribusi sering bertujuan menyembunyikan banyak
seluk-beluk yang berkaitan dengan distribusi proses, data, dan kontrol. Namun,
transparansi distribusi ini tidak hanya datang pada harga kinerja, tetapi dalam
situasi praktis tidak pernah dapat
sepenuhnya tercapai. Fakta bahwa trade-off harus dibuat antara pencapaian
berbagai bentuk transparansi distribusi melekat pada desain sistem
terdistribusi, dan dapat dengan mudah menyulitkan pemahaman pemakai.
REFERENSI :
>> Tanenbaum, distributed systems principles and paradigms 2nd edition, 2006
