The Ironstream agent subtasks collectively provide all the necessary communications and system interfaces. Each of the subtasks are dedicated to a particular interface function and communicates with other subtasks using the Ironstream agent interprocess communications queues.
Types of Subtask Queues
Each subtask uses the following two queues:
Subtask Input Queue
Queue used for messages destined for processing in the subtask interface. These messages can be commands for execution or messages to be transmitted to the Ironstream Proxy Server component.Subtask Output Queue
Queue used for messages that are the result of subtask processing. Messages from this queue are routed by the main task to other subtasks for processing.
TCP Subtask
The TCP/IP (TCP) subtask is an executable that requests the opening of two TCP/IP ports from the TCP/IP address space on the mainframe, then waits for the Ironstream Proxy Server component to start communication with the Ironstream IBM Z Agent through these ports. The TCP subtask accepts commands from the Ironstream Proxy Server component, routes them to the appropriate subtask for execution, and sends the replies back to the Ironstream Proxy Server component over a TCP/IP port.
As a rule, you must have one TCP subtask defined for each Ironstream Proxy Server component that will be connecting to the mainframe through TCP/IP.
Optionally, the TCP subtask will write messages to buffering datasets if the connection to the Ironstream server is lost. When communication is re-established, the stored messages will be forwarded to the server.
CMD Subtask
The Command (CMD) subtask is an executable that does the following:
Establishes an extended Multiple Console Support (MCS) console for Ironstream.
Receives z/OS commands (for example, Modify) from the Ironstream Proxy Server components.
Sends the commands to the defined console.
Receives the response messages from IBM Z LPAR.
Sends the responses back to the Ironstream Proxy Server component that initiated the command.
MVS Subtask
The MVS Messages (MVS) subtask is an executable that does the following:
Establishes an extended MCS console for Ironstream.
Receives z/OS messages and applies a filter to keep only desired messages.
Forwards messages to all active Ironstream server components.
SPO Subtask
The Secondary Program Operator (SPO) subtask is an executable that does the following:
Initializes a SPO Active Control Block (ACB) to VTAM.
Receives VTAM commands (for example, Vary or Display) from Ironstream Proxy Server component subtasks.
Sends the commands to VTAM over the SPO.
Receives the response messages from VTAM.
Sends response messages back to the Ironstream Proxy Server component subtask that initiated the command.
If several commands arrive at nearly the same time from different OMi operators, the Ironstream agent allows for multiple SPO subtasks to distribute the work.
PPO Subtask
The Primary Program Operator (PPO) subtask is an executable that initializes a PPO ACB to VTAM. This initialization enables the ACB to receive unsolicited messages from VTAM, most importantly messages about status changes of VTAM resources. The PPO subtask forwards these messages to all active Ironstream server subtasks.
Because VTAM allows only one application on the system to act as the PPO receiver, you should define the PPO subtask only if the system does not have another active PPO receiver,
such as NetView/390 or SOLVE:NETMASTER. If NetView/390 or SOLVE:NETMASTER is present, use the PPI subtask instead.
PPI Subtask
The Program-to-Program Interface (PPI) subtask is an executable that communicates with a user exit in the NetView/390 address space. Because the NetView/390 application controls the PPO connection to VTAM, the Ironstream agent requires that the exit be installed to pass on incoming VTAM information to the Ironstream agent. The PPI subtask then passes the VTAM message and alert data to the active Ironstream server component subtasks.
Use the PPI subtask only if a NetView/390 is present on the system. Otherwise, use the PPO subtask.
PERF Subtask
The Performance subtask (PERF) uses an API into IBM's Resource Monitoring Facility (RMF) to collect a wide range of data regarding the mainframe and jobs running on it. The PERF subtask solicits the RMF information on a user-defined time interval, and forwards the collected information to the OpenView performance sub-agent (CODA) or the Micro Focus Operations Performance Agent.
OSINFO Subtask
The Operating System Information subtask (OSINFO) collects on-demand information about the IBM Z system its active address spaces, DASD statistics, memory usage, and submitted jobs. These data can be requested at any time using a command script on the OVO management server to allow users to develop customized queries about the status of the mainframe.
Subtask Restart Function
The Ironstream agent has a subtask restart function that automatically restarts the mainframe subtasks when communication is lost from the host. This restart function eliminates the need to restart the entire Ironstream agent address space.