2. Outline
Conclusion
disadvantage
Architecture
Clustering
Definition HA
Introduction
1
3. Problematic
catastrophic
Normally, if a server with a particular
consequences
application crashes, the application will be
unavailable until someone fixes the crashed
server.
the lack of loss of money loss of integrity
productivity
2
4. Problematic
system downtime costs :
U.S. businesses $4.0
billion per year1
$140,000 loss in the
retail industry
$450,000 loss in the
securities industry2
3
5. Solution
• the solution to this problem is
the use of High Availability, or
HA, is the term associated with
computer systems which exhibit
almost no downtime
4
7. Definition
• computers, clustering is the use of
In can help an enterprise achieve 99.999 multiple
computers, instoragecases.
availability some devices, and redundant
interconnections, to form what appears to users
• a the outside available system
as tosingle highly world, the cluster appears to be a
single system.
6
8. Clustering
Cluster address
The teacher is solely responsible stewardship of EYP;
When a system in the cluster fails, the cluster
he can add,clustering technology, customers will be
Using edit or delete it. He also has the
softwareto incrementally add smaller, standardthe
possibility responds by dispersing the work from
able to attach to the EYP a document that
failed system todetailremaining systems in the cluster.
systems as the the EYP.
explains in more needed to meet overall processing
power requirements
7
9. When should we use HA clustering ?
HA clusters are often used :
• Critical databases
• File sharing on a network.
• Business applications.
• Customer services such as electronic
commerce websites.
8
11. Understanding Common terms
• HA clustering operate by having
a computer system that is an active or inactive
member of a cluster, used to provide service
when system components fail.
10
12. Understanding Common terms
• when we talk about high availability, we talk
about :
the process of taking a group of clustered
resources offline on one node and bringing them
online on another node.
11
13. Understanding Common terms
Each diskAttached of disks moves the cluster.only to
The ownership to all storage isfrom one node one
on the cluster nodes of owned by
another during failover or when a time
node of the cluster at the administrator
moves a group of resources to another node
12
14. HA TWO-NODE CLUSTER PLATFORM
Clients
Public LAN
Private LAN
Cluster
NODE1 NODE2
SAN
SCSI Interfaces
RAID Level 1
13
15. Disadvantage of HA
• The disavantage appears when we talk about
open-source High Availability Cluster:
• poor documentation and the lack of support
in the maintenance and customization
• can only be done by someone who has
experience with Linux/Unix.
14
17. Conclusion
the best way to setup a service
which must be high available
Upgrading servers is a lot less stressful if a
High Availability Cluster is used
16
Editor's Notes
This is the outline, first of all we have the introduction, then the defenition. afterthatwewillsee the clusetrring
imagine that this happens to a large company such as Amazon which has 100 billion stored objects and 760 million visitor per daythe consequences will be catastrophic as the lack of productivity, loss of money, loss of integrity
Content Layouts
In computers, clustering is the use of multiple computers, typically PCs or UNIX workstations, multiple storage devices, and redundant interconnections, to form what appears to users as a single highly available system. Cluster computing can be used for load balancing as well as for high availability. Advocates of clustering suggest that the approach can help an enterprise achieve 99.999 availability in some cases. One of the main ideas of cluster computing is that, to the outside world, the cluster appears to be a single system.
In broad terms, a cluster is a group of independent systems working together as a single system. A client interacts with a cluster as though it is a single server. Cluster configurations are used to address both availability and scalability:
For…Now I will give the floor te my coleaguehechmi ..
Content Layouts
The most common size for an HA cluster is a two-node cluster, since that's the minimum required to provide redundancy, but many clusters consist of many more, sometimes dozens of nodes.
Attached to all nodes of the cluster. Each disk on the cluster storage is owned by only one node of the cluster at a time. The ownership of disks moves from one node to another during failover or when the administrator moves a group of resources to another node
A High Availability Cluster is the best way to setup a service which must behigh available because several failures may occur and the service will still beavailable. Upgrading servers is a lot less stressful if a High Availability Cluster isused because there is always another server which will take over the connectionto the service.
