Clustered Dedicated Servers share the processing power with many servers in real time. Theses servers overcome the limitations of one physical server. This is also known as Grid web hosting technology. The advantage of these servers is that if one server has some threat then the other servers are available to share the load. Every server cluster which is set up for clients is customized to their requirements. Basically, cluster is an arrangement of normal servers; if user rent more than two servers then they will configure a private VLAN to provide secure gigabit communication between the servers.
Some benefits are there for ca lustered dedicated server:-
- Redundancy and Reliability: Different configurations in cluster server can give the user active or passive features in case of failure of one server. Passive feature involves running applications having redundant dedicated servers. Active configuration involves two-server sets run applications or services and takes data from common database in case of system failure.
- Load Balancing: To configure the server for maximum speed and performance when there is a lot of traffic might requires splitting traffic and functions among servers. Clustering allows anyone to improve services, operations and detect cyber attacks before downtime.
- High availability: Clustering reduces system failure and vulnerability. Implementation of databases, web servers, dual load balancers prevent downtime, cyber attacks and natural disasters.
Types of server clusters:
There are three different types of server clusters:-
- Single Quorum device cluster: It is also called the standard quorum cluster. There are multiple nodes with one or more which are also called cluster storage and it has also a connection device which is called bthe us.
- Majority node set cluster: In this type of cluster, each node maintains its own copy of the cluster configuration data. The resource keeps configuration data which is compatible across the nodes.
- Local Quorum Cluster: It is also called single node cluster which has sa ingle node and is used for testing.
The node configuration can be categorized into following models:
- Active/Passive: This configuration requires most extra hardware. It provides a fully redundant instance of every node.
- N+1: This refers to clusters that have multiple services running simultaneously. It provides a single extra node which is brought online to take over the role of failure node.
- N+M: It is used in cases where a single cluster is managing many services having one dedicated failover node.
- N-to-1: It allows the failover standby node to become the active one temporarily, until and unless original node can be restored.
- N-to-N: N to N clusters redistribute the services, instances or connections from the failure node among the active nodes and eliminate the need for ‘standby’ node.
The techniques which make shared infrastructure as reliable:
- Disk mirroring: It prevents internal disk failure to avoid system crashes. For example: Distributed Replicated Block Device.
- Redundant network connections: It prevents network outages from interface failures, single cable and switch or network.
- Redundant electrical power: It inputs to different circuits protected by uninterruptible power supply units which prevents from loss of power to the system.
Systems that handle failures have different strategies to cure:
- Fail Fast: It is the attempt to cure failures if the first node cannot be reached.
- On Fail, Try One-Next Available: It means the system tries one host which is most accessible or available.
- On Fail, Try All: It means the system tries all existing, available nodes.