Oracle 11gR2 RAC 中的 Grid Plug and Play(GPnP) 是什麼？

 

 

 

一. 什麼是GPnP？

 

Grid Plug and Play (GPnP)：Foundation for a Dynamic Cluster Management 

（1）GPnPeliminates the need for a per node configuration

–It is an underlying gridconcept that enables the automation of operations in the cluster 

–Allows nodes to be dynamicallyadded or removed from the cluster 

–Provides an easier managementto build large clusters OUI does not ask    

–It is the basis for the GridNaming Service (GNS) for a private node name anymore.  

 

（2）Technically,GPnP is based on an XML profile 

–Defining node personality(e.g. cluster name, network classification) 

–Created during installation 

–Updated withevery relevant change (using oifcfg, crsctl) 

–Stored in local files per homeand in the OCR 

- Wallet protected

 

（3） GPnPis apparent in things that you do not  

   see and that youare not asked for (anymore).

 

Grid Plug and Play (GPnP)eliminates per-node configuration data and the need for explicit add and deletenodes steps. This allows a systemadministrator to take a template system image and run it on a new node with nofurther configuration. This removes many manual operations, reduces theopportunity for errors, and encourages configurations that can be changedeasily. Removal of the per-node configuration makes the nodes easierto replace, because they do not need to contain individually-managed state.

    --GPnP 簡化了每一個節點的配置數據和添加刪除節點時的一些步驟。也就是說運行系統管理建立模板的系統鏡像，並在新的節點上運行，而不須要其餘的配置工做。這樣就減小了一些手工操做，下降了發生錯誤的機率。

 

Grid Plug and Play reduces the cost of installing, configuring, andmanaging database nodes by making their per-node state disposable. It allowsnodes to be easily replaced with regenerated state.

    --GPnP在每一個節點經過state來減小安裝，配置和管理數據庫的成本。

 

Grid Plug andPlay enables you to move your data center toward a dynamic grid infrastructure.This enables you to consolidate applications and lower the costs of managingapplications, while providing a highly available environment that can easilyscale when the workload requires.

 

There are manymodifications in Oracle RAC 11g release 2 (11.2) to support the easy additionof servers in a cluster and therefore a more dynamic grid.

 

 

In the past,adding or removing servers in a cluster required extensive manual preparation.With this release, Grid Plug and Play reduces the costs ofinstalling, configuring, and managing server nodes by automating the followingtasks:

--在過去的版本，添加刪除節點須要大量的手工準備，在11gR2中，以下任務經過自動化的操做，GPnP 減小了每一個節點安裝，配置和管理服務器的成本。

 

1)  Adding an Oracle RAC databaseinstance

2)  Negotiating appropriate networkidentities for itself

3)  Acquiring additionalinformation it needs to operate from a configuration profile

4)  Configuring or reconfiguringitself using profile data, making host names and addresses resolvable on thenetwork

 

--查看GPnP的進程：

[root@rac2 ~]# ps -ef|grep gpnp

grid     5124     1  0 15:26 ?        00:00:01/u01/app/grid/11.2.0/bin/gpnpd.bin

root     6646  4954  0 15:38 pts/0    00:00:00 grep gpnp

[root@rac2 ~]#

 

Grid Plug and Play (GPNPD): GPNPD provides access to the Grid Plug and Play profile, andcoordinates updates to the profile among the nodes of the cluster to ensurethat all of the nodes node have the most recent profile.

--GPnPD 進程能夠訪問Grid Plug and Play 的profile 文件，而且在集羣的全部節點中協調更新profile的內容。 已確保全部節點上的GPnP profile是最新的。

 

 

Multicast Domain Name Service (mDNS): Grid Plug and Play uses the mDNS process to locate profiles in thecluster, as well as by GNS to perform name resolution. The mDNS process is abackground process on Linux and UNIX, and a service on Windows.

    --GpnP 使用mDNS 進程來查找集羣中的profile文件，而後執行名稱解析。

 

 

The section, AboutPrivate Networks, Network Interfaces, and Network Adapters, says that theentity, Private network interfaces, is stored in the OracleClusterware, in the Grid Plug and Play (GPnP) Profile.

--entity，privatenetwork interface 的信息也會存入到Oracle Clusterwre 和Grid Plug and Play Profile中。

 

也就是說咱們在安裝過程當中配置某個interface做爲private interface或者使用oifcfg cluster_interconnects命令配置的private interface信息都會寫入到GPnP的profile中。

 

 

二. GPnP Profile 位置及內容

 

GPnP profile文件保存的是集羣的配置信息。這個XML 文件裏記錄了以下信息：

1.網絡接口和IP地址(公網和私網)

2.ASM diskstring和spfile信息

 

注意：Oracle不支持手動修改profile.xml文件，直接對它的修改可能致使沒法修復的問題，最終致使在全部節點重建Clusterware。

 

默認的保存位置是：

$GRID_HOME/gpnp/$HOSTNAME/profile/peer/profile.xml

$GRID_HOME/gpnp/profile/peer/profile.xml（全局備份）

 

 

在沒有啓動ASM 實例以前，diskgroup是沒有mount的，這時候啓動ASM 實例必需要讀取spfile文件。 

 

當ASM instance 查找初始化文件的時候，搜索的順序以下：

1.  GPnP（Grid Plug and Play） profile 中指定的本地位置

2.  若是GPnP profile中沒有指定初始化文件的位置，而後搜索ASM InstanceHome目錄。這裏會包含2種文件，SPFILE 和 PFILE，默認路徑是：$ORACLE_HOME/dbs/spfile+ASM.ora

 

在集羣環境下，集羣在啓動的時候,ClusterSynchronization Services (CSS)將掃描全部的ASM disks,它利用的是GPnP profile文件中的ASM discovery string。

 

在Oracle 10g 的RAC裏面， OCR 和Votingdisk是存放在單獨的raw設備上的，因此咱們能夠中止啓動ASM 實例。

 

可是在Oracle 11gRAC裏。Oracle 的架構作了變跟。 和ASM 的spfile同樣，OCR和Votingdisk 也存放到了ASM 的磁盤組裏。

 

這時候，在啓動CRS的時候，也必須經過GPnP 屬性文件來獲取OCR和votingdisk的信息。 而後在啓動ASM 實例和數據庫實例。

 

也正式如此，咱們在11G RAC環境下，不能中止ASM 實例，只能停數據庫實例。 ASM 實例只能和CRS 一塊兒中止。 由於CRS 依賴的文件存放在ASM 磁盤組上。

 

 

將profile.xml的內容複製出來，用瀏覽器打開，以下圖：

 

 

 

 

 

 

 

 

 

 

 

 

 

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