Please start any new threads on our new
site at https://forums.sqlteam.com. We've got lots of great SQL Server
experts to answer whatever question you can come up with.
| Author |
Topic |
|
srihari nandamuri
Starting Member
6 Posts |
 Posted - 2009-01-26 : 10:40:05
|
| Clustering is to make the high availablity of the server.It helps to up the server with no waste of time and the chance of loosing the transaction log will not exists.But this is costly in terms of clusture harware and software and its maintenance.Other options in place of FailOverClusturing:-1)log shipping(if we create transaction log for every 15 mins and in failed case we may loose the 1 mins of data) 2)Data base mirrorring(this does the same as clustur does on db-by-db basis fom the failed server to the backup server and is less expensive) .Clustering,It needs two physical servers(called nodes) .one acts as active node which will connect the database located on shared disc array.Other one will be inactive node which will connect the same database only when the failover of first active node happens.In general,sqlserver2005 without clustering will store the databases on local disk storage.But the clustered sqlserver2005 database is stored on a shared disk array(RAID 5 or RAID 10).This shared disc array must have atleast 2 logical partitions.One partition is used to store the clustered instance sqlserver database and the other partition is used for Quorum.Any changes made on active node will automatically gets updated on inactive node.And in case if active node gets failed any applied configuartion changes applied on active node will not be passed to inactive node. In this case the passive node before converting to active node will read this Quorum.This Quorum is a log file simillar to the database logs which stores all the changes applied to active node so that inactive node will read those changes and apply to it before becoming active.This is acced as quorum drive which is alogical drive on the shared disc drive.Each node requires two network cards.One to connect the Public network(where sql clients connects) and the other is the private network where the siganl of active is passed to the inactive node.Both the nodes will have the same virtual name and same ip address so that the sql clients will connect with that virtual name/ip address.Windows server 2003 enterprise edition is required to support the sqlserver2005 standard edition.with 2 node clusturing. Installing Microsoft Cluster Server (MSCS) requires two node clusterThe purpose of server clusters is to preserve client access to applications and resources during failures and planned outages. If one of the servers in the cluster is unavailable due to failure or maintenance, resources and applications move to another available cluster node. Network Requirements• A unique NetBIOS cluster name.• Five unique, static IP addresses: two for the network adapters on the private network, two for the network adapters on the public network, and one for the cluster itself.• A domain user account for Cluster service (all nodes must be members of the same domain).• Each node should have two network adapters—one for connection to the public network and the other for the node-to-node private cluster network. If you use only one network adapter for both connections, your configuration is unsupported. A separate private network adapter is required for HCL certification.Windows Clustering nodes as domain controllers and in this case below comments will workA single domain controller is always a single point of failure and this will bring down the cluster if it goes offline.Use at least two DCs on your network. Clustering requires DCs not only during setup but also for normal functioning and failover. Clustering always requires a domain account. If Installing SQL Server 2005 cluster on Virtual Environment.With virtualserver2005 ,creating one DC and two member servers(cluster nodes) is enough. and then making these two member servers as single cluster. For security reasons, Microsoft recommends that you do not install SQL Server on a domain controller.SQL Server Setup will not block installation on a computer that is a domain controller, but the following limitations apply:-On Windows Server 2003, SQL Server services can run under a domain account or a local system account.-You cannot run SQL Server services on a domain controller under a local service account or a network service account.-After SQL Server is installed on a computer, you cannot change the computer from a domain member to a domain controller. You must uninstall SQL Server before you change the host computer to a domain controller.-SQL Server failover cluster instances are not supported where cluster nodes are domain controllers. -SQL Server is not supported on a read-only domain controller. srihari nandamurisrihari nandamuri |
|
|
|
|
|
|
|
FailOver Clusturing in SQL2005 by srihari nandamur