Sun Microsystems iPlanet Integration Server 3.0, Руководство по системе управления

Страница: 105 / 368

Starting an Engine
Chapter 4 Managing Engines 105
Starting an Engine
To start an engine, you start each of its components—engine units, governor, and
database services. These components are applications, each consisting of a single
server partition that must establish communication channels with other
components.
As each of these partitions starts, it registers itself with the iPlanet UDS Name
Service and then looks in the Name Service registry for the names of other
components with which it must establish a communication channel. The
components can start in any order: they simply wait for the other components that
they connect to. When all necessary communication channels are established, the
primary engine unit can log on to its database and perform the operations that
bring it online.
Each of the engine components and its start characteristics are discussed in more
detail below. This background information is followed by instructions on how to
start the engine using the iIS Console. For information on starting engines using
Conductor Script, see
“Starting an Engine” on page 235 .
Governor
When the governor starts, it does not try to connect to anything, but enters a state
in which it is not connected to any engine units and waits for engine units to make
contact. When the engine units start up, the governor determines which unit is to
be primary and which is to be backup. There are three cases:
• If the first engine unit is marked as preferred primary, then the governor sets it
as the primary unit.
• If the first engine unit is marked as preferred backup, then the governor sets it
as the backup unit.
• If no engine unit is marked as preferred primary, then the governor sets the
first to start as primary unit.
If the governor starts up after the engine units and they have independently
established which is primary and which is backup, the governor accepts these
settings.