High Availability of Oracle

Quickly browsed the official Oracle Web page and unofficial PPT, and briefly understood the high availability solution provided by Oracle.

There are three main types:

 

1. RAC

 

RAC, real Application Clusters

 

Multiple Oracle servers form a shared cache, and these Oracle servers share a network-based storage. This system can tolerate single/or multi-host failures.

 

However, multiple nodes in the system need high-speed network interconnection. Basically, everything needs to be put in a data center or a data center. If the data center fails, for example, the network is disconnected, it will be broken. Therefore, using RAC alone cannot meet the needs of important services of Internet companies. Important services require multiple data centers to tolerate accidents in a single data center.

 

 

2. Data guard.

 

 

The data guard solution is suitable for multiple data centers. A production database is deployed in one data center, and standby databases are deployed in other data centers. Standby databases are physical and logical. The physical standby database is mainly used for switching after a production failure. The logical standby database can share the read load of the production database at ordinary times.

 

 

3. PAA

 

Maximum availability architecture is not the third independent architecture, but the combination of the first two to provide the highest availability.

 

 

A rac cluster is deployed in each data center, and data guard is used to synchronize multiple data centers.

 

 

 

Image Source:

 

Http://vnull.pcnet.com.pl/dl/oracle/Managing_Performance_for_RAC_1027041.pdf

 

Http://www.stanford.edu/dept/itss/docs/oracle/10g/server.101/b10726.pdf