Sun Microsystems iPlanet Integration Server 3.0, Руководство по системе управления

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iIS Process Engine Components
Chapter 1 Introduction: iIS Process Management 33
engine database is not supplied by the iIS product and must be set up
independently; however, the engine unit can create all required database tables at
startup time. The iIS process engine supports all relational database systems
supported by iPlanet UDS (for example, Sybase, Oracle, Informix, and so on).
Failover Configuration
To provide for failover in case the engine unit fails (for whatever reason), a backup
engine unit and governor are added to the iIS process engine configuration, as
illustrated in
Figure 1-3 .
Figure 1-3 Engine Configuration with Failover
Backup Engine Unit The backup engine unit, a replicate of the engine unit
partition, has a unique name that distinguishes it from the primary engine unit.
The primary and backup engine units are partners. The backup engine unit runs in
a standby state when the primary engine unit is on line. The two partners know
about each other through an open communication channel. If the primary engine
unit fails, the backup engine unit comes on line. In that case, the database service
iIS Process Engine
Backup
Engine
Unit
Governor
Primary
Engine
Unit
Engine
Database
Database
Service
Client Applications