Chapter 2. Components and functions 59
After the program is initialized, the MVS Listener begins to receive data from the
z/OS system and looks for the existence of a queue file that has the same
identifier as the z/OS system being monitored. For example, the queue file for
SC66 is SC66.que. If the queue file exists, it begins to insert data into the file. If
the file is not present, the MVS Listener then initializes a message queue file and
begins to insert data into it.
The Tivoli BSM MVS Event handler service (ASIMVSEventHandlerSvc)
periodically checks the message queue file for data. If the data is present, it
reads the message from the queue and inserts it into the database.
There are some commands executed automatically during the startup of
Source/390 following a system IPL or Source/390 restart. These commands
perform such tasks as initializing Source/390, registering objects, and requesting
file status. You can also use the Source/390 command from the IBM Tivoli
Business Systems Manager console using context menus of the operating
system object.
The automatic execution of these commands results in Source/390 sending state
information in the form of messages to the IBM Tivoli Business Systems
Manager servers. Upon receipt of these state messages, the Tivoli BSM MVS
Upload Rule Server service (ASIMVSUploadRuleSvc) evaluates the information,
formulates the proper commands to send, and finally uploads the proper
command or command set to Source/390, where they are executed. The MVS
Upload Rule Server service runs on the Event Server. Upload rule processing is
triggered by the event handler upon inserting the event into the database.
In addition to processing messages regarding the initialization of Source/390, the
MVS upload rule server evaluates other conditions that are of concern to the
proper execution of the Source/390 environment.
When the z/OS upload is enabled, the reply message is sent back to the Event
Server machine through the Tivoli BSM Enqueue Proxy Server
(ASIEnqueueProxyServer), which puts the events in an upload queue file. An
example of an upload queue file in our example environment is
SC66-Upload.que. The Tivoli BSM MVS Sender service (ASIMVSSenderSvc) or
Tivoli BSM MVS IP Sender service (ASIMVSIPSenderSvc) checks the queue
files and sends the message back to the Source/390. For the SNA connection, it
uses the ACC1RECV transaction program, which invokes the ACC1RECV
program in the object server address space. For the IP connection, it will connect
to the object server listening port, which typically is 1023.