We have discussed some basic high availability here.
Yesterday we were discussing about Windows clustering (here on will say “Clustering”) and realized that I have not blog much about clustering,
Here I will be considering 2 node clustering “Active -Passive” Clustering. the configuration and stuff here may varry depending upon the cluster configuration.also this is my understanding on clustering.
In this blog I am not going to detailed about the minimum requirement and configuration about clustering that will we discuss later. This blog is meant for general guideline about clustering.
It’s a windows cluster and on that we can add the resource to which we want failover (sql server). So we can failover any resource like sql server. Here we are discussing sql server failover.
Basic Requirements are:
Two Nodes : High end servers having similar configuration. (Memory/CPU)
Shared Storage device – SAN, we need a shared storage , which can be shared with both the nodes.
OS Requirement: As clustering required basic requirement supported by windows.
IPs:
- Virtual Server ip and Name : 1 IP
- Active Node IP and Name –Public IP: 1 IP
- Passive Node IP and Name –Public IP: 1 IP
- Active Node IP and Name –Private IP: 1 IP
- Passive Node IP and Name – Private IP: 1 IP
- Sql Server IP and Name : 1 IP
- Optional for 2008 onwards
- MSDTC IP and Name – 1 IP
This way we require minimum of 6 IP addresses.
- (1)Virtual: Virtual ip address is the ip which will be referred – which will be static and everyone can refer to it.
- (2)Public ips are ips require by every server to communicate
- (2)Private ips are used for checking heartbeat of the clustering, and if one node is down it will detect and failover to other node should be fast/good.
- (1) Sql server ip is also a static ip and will be same on either node.
Windows Configuration:
>> Windows cluster requires two servers with similar configuration
>> When we install the windows Operating system eg. Windows server 2008 enterprise edition. Cluster administrator (cluadmin) already installed on that server.
>> Now OS is installed. After this we want to make this two nodes
>> Require to mansion “Quarum” Drive which is important for maintaining log information about the failure of cluster for both the nodes.
Table 1 Power Sequencing Table for Cluster Installation
| Step | Node 1 | Node 2 | Storage | Comments |
| Setting Up Networks | On | On | Off | Verify that all storage devices on the shared bus are powered off. Power on all nodes. |
| Setting up Shared Disks | On | Off | On | Shutdown all nodes. Power on the shared storage, then power on the first node. |
| Verifying Disk Configuration | Off | On | On | Shut down first node, power on second node. Repeat for nodes 3 and 4 if necessary. |
| Configuring the First Node | On | Off | On | Shutdown all nodes; power on the first node. |
| Configuring the Second Node | On | On | On | Power on the second node after the first node was successfully configured. Repeat for nodes 3 and 4 if necessary. |
| Post-installation | On | On | On | At this point all nodes should be on. |
>> Create a Group for Shared Disk (Resource)
>> Sql server/ Agent/ … (Resource)
Map the resource with cluster group -Windows and Sql server.
| Dependencies:2000 | 2005 Resource Name | Dependencies |
| SQL IP AddressX (VSName) | SQL IP Address X (VSName) | None |
| SQL Network Name(VSName) | SQL Network Name (VSName) | SQL IP Address |
| SQL Server or | SQL Server | Disk Resource(s), SQL Network Name |
| SQL Server Agent | SQL Server Agent or | SQL Server |
Map name with IP (Name s are depends upon IP
* As stated earlier different ways to configure the same thing.
There are so many good information available on web about this.
