操作系统集群的工作方式
HCL Domino ®使用的集群方法称为应用程序集群。
Domino ®是一个应用程序,它监视集群并根据您设置的参数确定何时进行故障转移和工作负载平衡。另一种形式的集群是操作系统集群。
在这种形式的集群中,操作系统监视集群并确定何时应进行故障转移。发生故障转移时,故障转移到的服务器(称为节点)将接管故障节点的资源、访问故障节点正在访问的存储空间,并运行故障节点正在运行的应用程序。
有两种运行操作系统集群的基本方法,即主动-被动和主动-主动。在主动-被动集群中,被动节点不运行自己的应用程序,而是等待在主动节点出现故障时接管有故障的节点。在主动-主动集群中,所有节点都运行自己的应用程序,但也可以在集群中的其他节点出现故障时接管有故障的节点。此外,可以将操作系统集群配置为仅当存在硬件故障时进行故障转移,也可以将其配置为当存在硬件故障或软件失败时进行故障转移。
由于Domino ®使用应用程序集群,因此本节不提供有关操作系统集群使用的各种方法和配置的详细信息。但是,因为您可以将Domino®与多个操作系统集群一起运行,包括高可用性集群多处理 ( HACMP ™ ) 和Microsoft ™ Cluster Server (MSCS)。本节介绍操作系统集群的基本信息。
Operating system clusters provide failover that is transparent to users. Because the receiving node takes over the resources of the failed node, the user sees the same server name and same network address as on the original server. Unlike many operating system clusters, Domino® clustering does intelligent failover. When a server fails, Domino® checks its cluster cache to find the server that is most available in the cluster. Domino® also lets you actively control workload balancing, which operating clusters may not offer. In addition, Domino® clustering lets you set up clusters of servers that run different operating systems, while operating system clusters require that all nodes run the same operating system.
To run Domino® in an active-active cluster, you must use Domino® partitioned servers on the nodes. Doing so lets each node take over the tasks of the other node while also maintaining its own tasks.
要使用主动-主动配置,必须确保发生故障转移时每个节点都可以处理另一个节点的负载。
Benefits of using OS clusters with Domino® clusters
- Most Domino® agents do not fail over, so when a server fails over in a Domino® cluster, agents that were running do not continue running on the new server. If these agents are configured to run on a specific server, they will not be able to run on another server after Domino® failover occurs. In an operating system cluster, however, the same server name is used after failover occurs. Therefore, the agents can run on this server. In an operating system cluster, agents that were running on a schedule when failover occurred will restart the next time they are scheduled to run.
- If you have applications that use hard-coded server names, the applications will not work if they fail over to a different Domino® server. These applications will run after failing over in an operating system cluster, however, because the server name is still the same.
- If a user is editing a document when the server fails, the user can't save the document in a Domino® cluster. The user has to paste the document into a replica on the new server. In an operating system cluster, however, users can save documents that they were editing when the server failed.
- The Administration Process does not fail over in Domino®. Therefore, it is useful to set up operating system clusters for your administration servers.