Microsoft cluster solution (I)

Microsoft has been expanding the scalability, availability, and reliability of its server solutions for several years. Cluster technology has proved to be an effective way to achieve this goal
Microsoft fully supports the cluster technology concept and is committed to making it an integral part of the Microsoft operating system and related products. With windows
The official release of 2000, Microsoft cluster solution has gradually entered a mature stage.
Scalability, availability and reliability
A cluster is a group of independent computers that run the same set of applications in collaboration and provide a single system image for clients and applications. The purpose of cluster technology is to further improve the scalability, availability and reliability through multi-layer network structure.
Yes
Scalability refers to the ability of a computer to handle increasing workloads while maintaining acceptability. Hardware Device Scalability (implicit scaling, according to Microsoft) relies on
Large computers with scalability can perform various operations. Software Product Scalability (Extended expansion) relies on a cluster formed by multiple computers that work together in a collaborative manner.
Array is two different concepts. In fact, Microsoft uses an informal term computer redundancy array (RAC) to name its extended expansion cluster. Just like you can use a raid Array
You can also add nodes to the extended expansion Group to improve the performance.
Availability and reliability are closely related but slightly different.
. Availability refers to the existence of quality, backup capability, accessibility and accessibility. Reliability refers to the system strength. Even the most reliable system always has problems one day. Hardware equipment manufacturing
Vendors take advance preparation measures for possible failures by providing redundancy in key technical areas such as disk drives, power supply devices, network controllers, and cooling fans. However, in a single computing
The redundancy provided on the machine cannot prevent application faults. If the database software on a server fails, although the server may be very reliable, the software and server can work together.
The provided functions will still be unavailable. Therefore, a single computer cannot meet all the necessary scalability, availability, and reliability challenges undertaken by the cluster.
The cluster can simulate raid Arrays
To provide availability and reliability. In RAID 1 or raid
5. In such a fault-tolerant disk configuration scheme, all disks work in a Redundant Array. If a disk fails, you can unplug it and insert a new disk.
Line-No configuration, no installation, and most importantly, no downtime. The RAID system automatically reconstructs the new drive so that it can work with other drives. Similarly, when
When a computer fails, you only need to replace it with a new system, and the entire cluster will continue to run. Some Cluster software can automatically configure the server and integrate it into the cluster.
-- All related operations are completed when the cluster is available.
Four cluster Solutions
Microsoft provides four basic cluster technologies: Microsoft group
Set Service (MSC), network load balancing (NLB), Component Load Balancing (CLB) and Application Center
2000. These services are provided through three solutions: MSC, NLB, and Application Center. CLB is application
And can only be applied through the Application Center. NLB can use application
It can also be used as an independent solution. Windows 2000 Advanced Server and Windows 2000
The datacenter server itself contains MSC and NLB, but you must purchase the application center separately.
Table 1 summarizes the four populations
Integration Technology in Different Windows 2000 Server and Windows NT Server
4.0 availability of product family members. None of these technologies are applicable to Windows 2000 Professional or Windows
NT Workstation 4.0.
　
　
Microsoft cluster service
Most
Initially named wolfpack and known as Microsoft Cluster Server and Microsoft cluster service, the MSC is Microsoft's technical field in the NT Cluster
For the first time, it was recognized as the best Microsoft cluster solution. In the MSC cluster, the MSC Software can establish connections with up to four physical computers running on the high-speed network. Connect
Generally, computers in a cluster can share the same storage subsystem and functions in the "activity-activity" mode, which means that all cluster computers (nodes) can actively collaborate through load sharing.
Work, and share its work when a node fails. Figure 1 shows a 4-node MSC cluster.

Figure 1 4-node cluster implemented by Windows 2000 MSC
MSC
The main purpose is to improve application availability through its fault tolerance capabilities. Fault Tolerance refers to the fault application that processes the fault from a node (due to hardware equipment failure or software error and other reasons ).
To the cluster function on other healthy nodes in the cluster. After the faulty application is restored, the cluster should be able to implement "fault return" for the original cluster node ". Yes.
Manages the fault recovery and return of applications running on the cluster based on application-related data, and maintains the user and application status during the fault recovery process. This type of cluster function is
It is called the stateful cluster function. In contrast, NLB, CLB, and Application
While enhancing availability, the center provides stateless clustering and Dynamic Load Balancing (I will discuss this in detail later ).
For e-mail servers
For applications such as data library applications, MSC is a good running method. Suppose you decide to run microsoft exchange on a 4-node MSC Cluster
2000 Server. After you install the MSC Software and the Exchange 2000 version for the cluster, you can configure the cluster to enable exchange
2000 fault recovery can be performed on the backup node when the primary node fails. When a fault occurs, there must be a user session in the active state on the master server.
Data can be quickly and automatically restored. The backup node will replace the workload and related data from the faulty node and continue to provide services to users.
At the same time, the user can
Continue to work during program upgrade. You can use the rolling Upgrade Method (for example, upgrading applications on one cluster node each time and ensuring that applications on other nodes continue to be available) without upgrading
Stop using applications during the process. For example, assume that you have a dual-node cluster. Node 1 runs Exchange 2000, and node 2 runs Microsoft SQL
Server, you want to configure this cluster so that Exchange 2000 and SQL server can implement fault recovery between each other if necessary. When you need
When upgrading the SQL server, you can start the SQL server fault recovery function on node 2 through the MSC Cluster Manager. When Node 1 takes over SQL
When the server runs a task (Exchange 2000 continues at the same time), you can
Server. After the upgrade is complete, you can use the fault return method to migrate SQL Server from node 1 to node 2 to run the SQL server on node 1.
The server repeats the same software upgrade operation. After Node 1 completes the upgrade, the entire SQL Server Software completes the upgrade task without affecting user usage.
And
The other three Microsoft cluster solutions are different, and you generally cannot use MSC to expand applications for more users. The MSC cluster cannot send data to NLB, CLB, and
Application
In this way, the center provides dynamic load balancing capabilities between nodes through stateless non-shared mode or implements distributed application running. In fact, it is the only feasible method to implement the application scaling capability by using MSC.
You can manually allocate applications to different cluster resources during the installation process. For example
The 2000 platform provides services for 5000 users. you can apply a 2-node activity-Activity cluster and provide services for 2500 users on each node. In this way, you can obtain
Servers provide services to users to achieve performance advantages, while also achieving necessary availability in case of faults. However, when a fault is restored, the remaining nodes must be able
All 5000 users provide services.