High Availability with Load balancing and clustering

High Availability With Load Balancing And ClusteringCreated By: ZEEL SHAH Guide: SONAL CHRISTIE

CERTIFICATEThis is to certify that Zeel N Shah MSC.ITIMS Student of Gujarat University-Ahmedabad, Gujarat has done Project on High Availability with load balancing and clustering under the guidance and supervision of Mrs. SONAL CHRISTIE. To the best of my knowledge and belief, this work embodies the work of candidate himself, has properly been completed, fulfills the requirement of the ordinance relating to the Master degree of the university and is up to the standard in respect of content, presentation and language for being referred to the examiner.

High availability

What is Availability ?The term available describes a system that provides a specific level of service as needed.Availability is generally understood as the period of time when services are available or as the time required for the system to respond to users. Any loss of service, whether planned or unplanned, is known as an outage.The term downtime is used to refer to periods when a system is unavailable.A planned outage is the result of a planned activity by the system owner and/or by a service provider.Unplanned downtime is downtime that occurs as a result of a failure Because administrators do not know when unplanned downtime could occur, users are not notified. Continuous AvailabilityContinuous availability means non-stop service, that is, there are no planned or unplanned outages at all.continuous availability is an ideal state rather than a characteristic of any real-world system. This term is sometimes used to indicate a very high level of availability in which only a very small known quantity of downtime is acceptable.High Availability needed as per requirement like1)As a Business Requirement2)As an Insurance3)As Opportunity

Cost of High AvailabilityThe higher the cost of an outage, the easier it becomes to justify the expense of HA solutions.As the degree of availability approaches the ideal of 100% availability, the cost of the solution increases more rapidly.Thus, the cost of 99.95% availability is significantly greater than the cost of 99.5% availability; the cost of 99.5% availability is significantly greater than 99%, and so on.Network Load BalancingNetwork load balancing is the ability to balance traffic across two WAN links without using complex routing protocols like BGP. This capability balances network sessions like Web, email, etc. NLB uses a distributed algorithm to balance IP traffic load across multiple hosts.It helps to improve the scalability and availability of business-critical, IP-based services.Windows server 2012 NLB clusters can have between two and 32 nodes.NLB is failure-aware. This means that if one of the nodes in the NLB cluster goes offline, requests will no longer be forwarded to that node, but other nodes in the cluster will continue to accept requests.

MS Technology For NLBMicrosoft has also developed a technology called Network Load Balancing (NLB) that allows for efficient utilization of multiple network cards.MS NLB can be configured in unicast or in multicast mode.MS NLB was introduced for the first time in Windows NT server to spread traffic over multiple hosts without the need for a hardware based load balancer.MS NLB have two modes:1)Unicast Mode 2)Multicast Mode

Server Load BalancingWhen multiple servers are joined to create a cluster. Clusters can use network load balancing whereby simultaneous cluster request are distributed between cluster servers.NLB is able to detect the failure of cluster nodes. When a cluster node is in a failed state, it is removed from the cluster, and the cluster does not direct new traffic to the node.Failure is detected by using heartbeats. NLB cluster heartbeats are transmitted every second between nodes in a cluster.A node is automatically removed from a NLB cluster if it misses five consecutive heartbeats. When a node is added or removed from a cluster, a process known as convergence occurs.By default, a host that is a member of a cluster will attempt to rejoin that cluster automatically.

How NLB Works?When we configure an application to use NLB, clients address the application using the NLB cluster address rather than the address of nodes that participate in the NLB cluster.For example, if you have a four node cluster where three of the nodes are responding to requests from 10 clients and one node is responding to requests from 5 clients, the node that has fewer clients will receive more evenly balanced across the nodes.Network load balancing (commonly referred to as dual-WAN routing or multihoming) is the ability to balance traffic across two WAN links without using complex routing protocols like BGP.

Select Automated Deployment MethodWe should manually deploy NLB only if creating and testing the automation files and scripts would take more time than manually configuring the cluster.You can automate the deployment of Windows Server 2008 and NLB cluster hosts by using one of the following methods: Windows Deployment Services (WDS) Unattended installationSysprep

Depending on the requirements of each cluster, more than one method might be required to deploy all your NLB clusters.The NLB-specific installation and configuration information is required in the Microsoft-Windows-Network LoadBalancing-Core section of the unattended answer file.Lab Implementation On Network Load Balancing12Lab Scenario

Here in server 2008 create domain name as zeel.com

After creating domain, Install IIS server and than create one web site.

This is the web page of first server.

Than Install the feature of Network Load Balancing

Same process done in second member server.Now on the NLB server create a new cluster and add two domain member in that cluster.

By default the new cluster priority is 1.

Add two domain member in NLB cluster

Two members are add in the cluster.

After adding two server access server at client side with IP 50.0.0.25.

Here we can see than first server gives the response to the client but if this server is fail to gives response than other member server gives reply.After disable the first server other server gives the response to the client.

Network Load Balancing in server 2012First create domain in server 2012.

Server 2k12 is the member of domain

23Create IIS server in domainInstall NLB feature in both domain member.

Web page of both server

Configure Network manager and access it by client.

Volume Shadow CopyApplications that are running often keep their files open continuously. For backup, this can present a problem because this prevents backup applications from accessing and copying this files to backup media.

The volume shadow copy service provides interfaces for storage- management applications ( called requestors) , business applications ( called writers) and storage devices ( with components called providers) to ensure that volume shadow copies are in a consistent state.

Methods for Creating Shadow CopiesThere are two methods for creating shadow copies: making either a complete copy (a full copy or clone) or copying only the changes to the volume (a differential copy or copy-on-write). Each method results in two data images the original volume and the shadow copy volume.The functional difference between the two is that the original volume maintains full read/write capabilities, whereas the shadow copy volume is read-only. This read-only status ensures that the shadow copy volume remains a point-in-time copy until its status is changed by the administrator for a specific purpose.

Lab Implementation On Volume Shadow Copy

30Create file in C: and than configure the shadow copy on drive .

If any user change the data of C:. So If we want our data back than go to drives property Previous version Restore

So original data is back.

Here some files are deleted by any user. So go to folders property previous version restore it.

So all the deleted files are back.

Configure volume shadow copy in server 2012

Fail over clustering in windows server 2012A failover cluster is a group of independent computers that work together to increase the availability and scalability of clustered roles (formerly called clustered applications and services).The clustered servers (called nodes) are connected by physical cables and by software. Failover clusters also provide Cluster Shared Volume (CSV) functionality that provides a consistent, distributed namespace that clustered roles can use to access shared storage from all nodes. With the Failover Clustering feature, users experience a minimum of disruptions in service.Window Server 2012/R2 Failover Clustering provides the capability to tie multiple servers together to offer high availability and scalability for business-critical applications such as Microsoft Exchange, Hyper-V, Microsoft SQL Server, and file servers.

Shared folders in a failover cluster :-In Windows Server2008, the interfaces for viewing or configuring shared folders in a failover cluster have been extended and streamlined. Configuration is more straightforward and misconfiguration is less likely.

Nodes:-Individual servers or members of a cluster are referred to as nodes or systems (the terms are Used interchangeably). A node can be an active or inactive member of a cluster, depending on Whether or not it is currently online and in communication with the other cluster nodes.

Cluster Services:-Cluster service refers to the collection of clustering software on each node that manages all Cluster-specific activity.

Shared Disks:-Shared disks are devices (normally hard disk drives) that the cluster nodes are attached to by a shared bus. Applications, file shares, and other resources to be managed by the cluster are stored on the shared disks.

Resources:-A resource can only run on a single node in a cluster at a time, and is online on a node when it is providing its service on that node.

At any given time, a resource can exhibit only one of the following states: Offline Offline pending Online Online pending Failed

QuorumsThe Windows Server 2008 failover clustering quorum model is entirely new and represents a Blend of the earlier shared disk and majority node set models. In Windows Server 2008 failover clustering there are now four ways to establish a quorum. 1)Disk Only2)Majority Node Set3) Node and File Share Majority4) Node and File Share Majority

FailOverFailover is the process of moving a group of resources from one node to another in the case of a failure. For example, in a cluster where Microsoft Internet Information Server (IIS) is running on node A and node A fails, IIS fails over to node B of the cluster.

Lab Implementation On Fail Over Clustering45Fail over clustering in windows server 2012

Fail over clustering in windows server 2012

Here server 2012 is domain server and server 2008 is the member server of domainIn domain server install starwind software. And add two VHD in that.

Than configure the cluster wizard , add both member server in cluster.

After validating cluster , it generates the report.

Than create a cluster. And access point of administering is 10.0.0.5

Both server member add in failover cluster manager. And both servers are online now.

Fail over cluster is created for shared folder. Give the permission to the shared folder.

Give the permission to the users.

And fail over clustering on shared folder is created successfully.

After than configure the quorum disk.

Other disk is worked as witness disk. So if any disk is fail than from other disk user get the response.

THANK YOU62