Kbase P113880: What are the major Progress AppServer Run-time Components?
| Autor |
Progress Software Corporation - Progress |
| Acesso |
Público |
| Publicação |
3/8/2006 |
|
Status: Unverified
GOAL:
What are the major Progress AppServer Run-time Components?
FACT(s) (Environment):
Progress 9.x
FIX:
The major Progress AppServer run-time components are:
1. 4GL Client Application (uses an interface of built-in 4GL statements and functions dedicated to the AppServer process):
. 4GL client session
. WebSpeed 4GL session (WebSpeed Agent)
. AppServer session (Application Server process)
2. Non-progress clients:
. Java and ActiveX clients Access the AppServer through a set of custom built objects using the added Progress product, Open Client Toolkit.
3. Application Server Process:
. A process that executes remote procedure request in the context of a progress session.
. An AppServer instance usually contains multiple Application Server processes that start on start of the AppServer.
. An Application Server process can act as a 4GL client of another AppServer instance by making its own remote procedure calls.
4. Application Broker:
. A process that creates, manages, and allocates Application Server processes for access by client applications.
. The Application Broker allocates client request based on the configured operation mode.
. A single Application Broker supports one AppServer instance.
5. NameServer:
. A process that can be used to direct client connections to an AppServer that supports a specified business function. The business function is reflected by the
Application Service listed within the client connection statement and registered with the NameServer on startup of the AppServer. The client only needs to know
the host and the port of the NameServer along with the Application Service.
. Multiple NameServers can be set up with fault-tolerance. Setting up multiple NameServers on the same subnet with identical information.
The NameServer communicates with UDP(User Datagram Protocol) and in this case the client connection requests would use the broadcast IP address allowing
connection-level
fault-tolerance.
. If the Load Balancing Progress product is installed, multiple AppServers can support the same Application Service.
The NameServer can then distribute client connections among the available AppServers according the information registered by the AppServers, giving a server
level fault tolerance.