Oracle® Database 10g R2 实战：Real Application Clusters 指南
需积分: 10 11 浏览量
更新于2024-07-29
收藏 1.54MB PDF 举报
"Oracle® Database 2 Day + Real Application Clusters Guide"
Oracle Real Application Clusters (RAC) 是 Oracle 数据库的一项重要特性，它提供了一种高可用性和可伸缩性的解决方案，允许数据库在多台服务器上进行共享，从而实现故障切换和负载均衡。这本官方指导手册旨在为用户详细介绍如何配置、管理和使用 RAC 系统。
在 10g Release 2 (10.2) 版本中，Oracle RAC 提供了以下关键知识点：
1. **RAC 基础**: RAC 实际上是一组物理服务器，它们通过高速网络连接共享一个物理数据库。每个服务器都是一个节点，它们共同构成了一个集群。这种设计使得数据库可以在节点之间无缝地分布工作负载，并在单个节点出现故障时自动转移服务。
2. **集群ware**: Oracle Clusterware 是 RAC 的核心组件，负责管理集群的健康状态，监控节点间的通信，并在出现问题时执行故障恢复。Clusterware 包括一系列服务和进程，如 OCR（Oracle Cluster Registry）用于存储集群配置信息， Voting Disks 用于节点间的决策。
3. **Grid Infrastructure**: Oracle Grid Infrastructure 是包含 Clusterware 和 ASM（Automatic Storage Management）的集合，ASM 提供自动化的存储管理，简化了存储配置，并支持 RAC 集群的动态扩展。
4. **数据存储**: 在 RAC 中，数据被存储在共享磁盘组中，由所有节点访问。ASM 可以创建和管理这些磁盘组，确保数据的一致性和可用性。
5. **故障检测与恢复**: RAC 使用多种机制来检测节点或服务的故障，如 heartbeat 机制。一旦检测到故障，Clusterware 将自动将服务迁移到健康的节点，确保业务连续性。
6. **负载均衡**: 负载均衡是 RAC 的重要功能之一，它能根据各个节点的当前负载情况动态分配 SQL 请求，以优化系统性能。
7. **ASM 和 RAC 结合使用**: ASM 与 RAC 结合，可以创建高可用的存储解决方案，ASM 自动管理磁盘组的创建、扩展和故障恢复，减轻管理员的工作负担。
8. **SQL Parallel Execution**: RAC 支持并行执行 SQL 查询，这意味着复杂的查询可以被分解并在多个节点上同时执行，显著提高了处理大数据量的能力。
9. **应用透明性**: 对于应用程序来说，RAC 是透明的，应用程序无需知道数据是在哪个节点上处理的，只需连接到集群的全局数据库名称。
10. **安装与配置**: 指南会详细阐述 RAC 的安装步骤，包括硬件和网络需求、软件安装、数据库创建、集群配置等。
11. **安全管理**: RAC 需要对集群的所有组件进行安全配置，包括网络、操作系统、数据库和应用层。指南将介绍如何设置适当的权限和认证机制。
12. **性能调优**: 由于 RAC 的复杂性，性能调优是关键，包括调整参数、优化网络、SQL 调优等，以达到最佳的集群性能。
通过这本《Oracle® Database 2 Day + Real Application Clusters Guide》，读者可以深入了解 RAC 的各个方面，从基础概念到高级操作，全面掌握构建和维护高可用性数据库集群的技能。
Tools for Installing, Configuring and Managing Oracle RAC
1-4 Oracle Database 2 Day + Real Application Clusters Guide
the disk level. Mirroring means keeping redundant copies, or mirrored copies, of
each extent of the file, to help avoid data loss caused by disk failures. The mirrored
copy of each file extent is always kept on a different disk from the original copy. If
a disk fails, ASM can continue to access affected files by accessing mirrored copies
on the surviving disks in the disk group.
■ Online storage reconfiguration and dynamic rebalancing—ASM permits you to
add or remove disks from your disk storage system while the database is
operating. When you add a disk, ASM automatically redistributes the data so that
it is evenly spread across all disks in the disk group, including the new disk. The
process of redistributing data so that it is also spread across the newly added disks
is known as rebalancing. It is done in the background and with minimal impact to
database performance.
■ Managed file creation and deletion—ASM further reduces administration tasks
by enabling files stored in ASM disk groups to be managed by Oracle Database.
ASM automatically assigns file names when files are created, and automatically
deletes files when they are no longer needed.
ASM is implemented as a special kind of Oracle instance, with its own System Global
Area and background processes. The ASM instance is tightly integrated with the
database instance. Every server running one or more database instances that use ASM
for storage has an ASM instance. In an Oracle RAC environment, there is one ASM
instance for each node, and the ASM instances communicate with each other on a
peer-to-peer basis. Only one ASM instance is required for each node regardless of the
number of database instances on the node.
Oracle recommends that you use ASM for your database file storage, instead of raw
devices or the operating system file system. However, databases can have a mixture of
ASM files and non-ASM files.
Tools for Installing, Configuring and Managing Oracle RAC
The following is a description of the tools used for installing, configuring, and
managing an Oracle RAC database:
■ Oracle Universal Installer (OUI)–OUI installs the Oracle Clusterware and the
Oracle Database software with Oracle RAC. After you configure the nodes that
you want to use in your cluster, OUI installs the Oracle software on the specified
nodes using a network connection.
■ Cluster Verification Utility (CVU)–The CVU is a command-line tool that you can
use to verify a range of cluster and Oracle RAC components such as shared
storage devices, networking configurations, system requirements, and Oracle
Clusterware, as well as operating system groups and users. You can use the CVU
for preinstallation as well as postinstallation checks of your cluster environment.
The CVU is especially useful during preinstallation and during installation of
Oracle Clusterware and Oracle RAC components. OUI runs the CVU after the
Oracle Clusterware installation to verify your environment.
■ Oracle Enterprise Manager –Oracle Enterprise Manager has both the Database
Control and Grid Control graphical user interfaces (GUIs) for managing single-
instance and Oracle RAC environments.
■ Server Control (SRVCTL)–SRVCTL is a command-line interface that you can use to
manage an Oracle RAC database from a single point. You can use SRVCTL to start
and stop the database and instances, and to delete or move instances and services.
You can also use SRVCTL to add services and manage configuration information.
You use SVRCTL to start and stop a group of applications that includes virtual IP
剩余165页未读，继续阅读
2023-06-18 上传
2018-05-15 上传
2018-06-08 上传
2011-02-22 上传
2009-08-14 上传
2009-07-15 上传
2008-11-20 上传
2008-11-20 上传
2012-10-13 上传
