HCL OneTest™ API and Agent for z/OS technical overview

Multiple software components are involved in the recording and virtualization of EXEC SQL statements. On z/OS, IBM z/OS Debugger intercepts the EXEC SQL commands. The information involved in the EXEC SQL statements is then passed to the Agent for z/OS, which runs on either a Windows or Linux system. (During the beta period, only Windows is supported).

The agent polls HCL Quality Server to determine whether any HCL OneTest™ API users are recording, or whether any stubs are running. If the agent finds any active recording sessions or stubs, the agent passes the Db2® EXEC SQL related data to them, based on the criteria specified within the Agent for z/OS filter.

This diagram illustrates the interaction between HCL OneTest™ API, HCL Quality Server, the Agent for z/OS, and IBM z/OS Debugger when you record EXEC SQL statements from a program that runs under CICS. The events that occur when you record a program that runs as part of a batch job are different.

Agent for z/OS overview

  1. Within the Recording Studio of HCL OneTest™ API, you select a Db2® event monitor, and start recording.
  2. You are prompted to specify the name of an Agent for z/OS Filter that contains the filter criteria to use to determine which programs SQL statements to record. The filter criteria can include the program name, the ID of the user running the program, the terminal or IP address from which the program was initiated, or several other factors.
  3. HCL OneTest™ API passes the recording rule to HCL Quality Server, which then notifies the Agent for z/OS of the rule.
  4. The Agent for z/OS contacts the Profile Service in IBM z/OS Debugger to create a DTCN profile that contains the filter criteria, the host name, and port number where the agent is running, and a unique identifier for the recording session in HCL OneTest™ API.
  5. You start the program under test within CICS.
  6. IBM z/OS Debugger traps the EXEC SQL statement and passes it to the Agent for z/OS.
  7. The Agent for z/OS passes the SQL statement and any result set to HCL OneTest™ API.
  8. If a stub is created from the recording, the Db2® artifacts are created or updated within the simulation database.

Agent for z/OS considerations

Consider the following points about the Agent for z/OS:

  • The Agent for z/OS intercepts calls from programs that are running on z/OS to Db2® running on z/OS. Because the agent runs on another platform, the speed and latency of the network connection between the z/OS system and the Agent for z/OS can impact performance.
  • A single instance of the agent can accommodate multiple Db2® subsystems across multiple z/OS systems.
  • Each transport is associated with a simulation database schema. All stubs associated with the transport share the simulation database and schema. For this reason, stubs associated with a transport must only be run one at a time.
  • The agent appears to HCL Quality Server as both an Agent for z/OS and a JDBC agent.