Oracle B12255-01 Manuale Utente
mod_onsint
Oracle HTTP Server Modules
7-13
mod_onsint
This module provides integration support with Oracle Notification Service (ONS)
and OPMN (Oracle Process Manager and Notification Server).
and OPMN (Oracle Process Manager and Notification Server).
Benefits of mod_onsint
mod_onsint
provides the following functionality:
■
Provides a subscription mechanism for ONS notifications within Oracle HTTP
Server. This is particularly important on UNIX where Oracle HTTP Server
employs a multi-process architecture. In such an architecture, it is not feasible to
have an ONS subscriber in each process since there are up to 8192 processes
that comprise a single Oracle HTTP Server instance. Instead, mod_onsint
provides a single process that receives notification for all modules within an
Oracle HTTP Server instance.
Server. This is particularly important on UNIX where Oracle HTTP Server
employs a multi-process architecture. In such an architecture, it is not feasible to
have an ONS subscriber in each process since there are up to 8192 processes
that comprise a single Oracle HTTP Server instance. Instead, mod_onsint
provides a single process that receives notification for all modules within an
Oracle HTTP Server instance.
■
Publishes PROC_READY ONS notifications so that other components such as
OPMN are notified that the listener is up and ready. It also provides
information such as DMS metrics and information about how the listener can
be contacted. These notifications are sent periodically by mod_onsint as long
as the Oracle HTTP Server instance is running.
OPMN are notified that the listener is up and ready. It also provides
information such as DMS metrics and information about how the listener can
be contacted. These notifications are sent periodically by mod_onsint as long
as the Oracle HTTP Server instance is running.
■
Provides functionality that enables Oracle HTTP Server to terminate as a single
unit if the parent process fails. The parent process is responsible for starting and
stopping all of the child processes for an Oracle HTTP Server instance. The
failure of the parent process without first shutting down the child processes
leaves Oracle HTTP Server in an inconsistent state that can only be fixed by
manually killing all of the orphaned child processes. Until this is done, a new
Oracle HTTP Server instance cannot be started since the orphaned child
processes still occupy the ports Oracle HTTP Server wants to use. mod_onsint
provides a monitor of the parent process. If it detects that the parent process has
died, it kills all of the remaining child processes. When combined with OPMN,
this provides restartability for Oracle HTTP Server in the case of a parent
process failure. mod_onsint ensures that all of the Oracle HTTP Server child
processes die, leaving the ports open for a new Oracle HTTP Server instance.
OPMN ensures that a new instance is started once the failure of the original
instance is detected.
unit if the parent process fails. The parent process is responsible for starting and
stopping all of the child processes for an Oracle HTTP Server instance. The
failure of the parent process without first shutting down the child processes
leaves Oracle HTTP Server in an inconsistent state that can only be fixed by
manually killing all of the orphaned child processes. Until this is done, a new
Oracle HTTP Server instance cannot be started since the orphaned child
processes still occupy the ports Oracle HTTP Server wants to use. mod_onsint
provides a monitor of the parent process. If it detects that the parent process has
died, it kills all of the remaining child processes. When combined with OPMN,
this provides restartability for Oracle HTTP Server in the case of a parent
process failure. mod_onsint ensures that all of the Oracle HTTP Server child
processes die, leaving the ports open for a new Oracle HTTP Server instance.
OPMN ensures that a new instance is started once the failure of the original
instance is detected.