Technical data

10 Recovering Failed Servers
10-2 Configuring and Managing WebLogic Server
Automatic Restart for Managed Servers
WebLogic Server provides self-health monitoring to improve the reliability and
availability of server instances in a domain. Selected subsystems within each
WebLogic Server instance monitor their health status based on criteria specific to the
subsystem. (For example, the JMS subsystem monitors the condition of the JMS thread
pool while the core server subsystem monitors default and user-defined execute queue
statistics.) If an individual subsystem determines that it can no longer operate in a
consistent and reliable manner, it registers its health state as “failed” with the host
server.
Each WebLogic Server instance, in turn, checks the health state of its registered
subsystems to determine its overall viability. If one or more of its critical subsystems
have reached the
FAILED state, the server instance marks its own health state FAILED
to indicate that it cannot reliably host an application.
When used in combination with Node Manager, server self-health monitoring enables
you to automatically reboot servers that have failed. This improves the overall
reliability of a domain, and requires no direct intervention from an administrator.
For information on this feature, see “Node Manager Capabilities” on page 3-5.For
instructions to configure Node Manager and automatic restart behaviors, see
“Configuring Node Manager” on page 4-1.
Managed Server Independence Mode
When a Managed Server starts, it tries to contact the Administration Server to retrieve
its configuration information. If a Managed Server cannot connect to the
Administration Server during startup, it can retrieve its configuration by reading
configuration and security files directly. A Managed Server that starts in this way is
running in Managed Server Independence (MSI) mode. By default, MSI mode is
enabled. For information about disabling MSI mode, see “Disabling Managed Server
Independence” in Administration Console Online Help.
In Managed Server Independence mode, a Managed Server looks in its root directory
for the following files:
! msi-config.xml—a replica of the domain’s config.xml.(Even if the
domain’s configuration file is named something other than
config.xml,a