The PowerCenter Integration Service starts a PowerCenter Integration Service process to run and monitor workflows. The PowerCenter Integration Service process is also known as the pmserver process. The PowerCenter Integration Service process accepts requests from the PowerCenter Client and from
pmcmd
. It performs the following tasks:
Manage workflow scheduling.
Lock and read the workflow.
Read the parameter file.
Create the workflow log.
Run workflow tasks and evaluates the conditional links connecting tasks.
Start the DTM process or processes to run the session.
Write historical run information to the repository.
Send post-session email in the event of a DTM failure.
Manage PowerCenter Workflow Scheduling
The PowerCenter Integration Service process manages workflow scheduling in the following situations:
When you start the PowerCenter Integration Service. When you start the PowerCenter Integration Service, it queries the repository for a list of workflows configured to run on it.
When you save a workflow. When you save a workflow assigned to a PowerCenter Integration Service to the repository, the PowerCenter Integration Service process adds the workflow to or removes the workflow from the schedule queue.
Lock and Read the PowerCenter Workflow
When the PowerCenter Integration Service process starts a workflow, it requests an execute lock on the workflow from the repository. The execute lock allows the PowerCenter Integration Service process to run the workflow and prevents you from starting the workflow again until it completes. If the workflow is already locked, the PowerCenter Integration Service process cannot start the workflow. A workflow may be locked if it is already running.
The PowerCenter Integration Service process also reads the workflow from the repository at workflow run time. The PowerCenter Integration Service process reads all links and tasks in the workflow except sessions and worklet instances. The PowerCenter Integration Service process reads session instance information from the repository. The DTM retrieves the session and mapping from the repository at session run time. The PowerCenter Integration Service process reads worklets from the repository when the worklet starts.
Read the Parameter File
When the workflow starts, the PowerCenter Integration Service process checks the workflow properties for use of a parameter file. If the workflow uses a parameter file, the PowerCenter Integration Service process reads the parameter file and expands the variable values for the workflow and any worklets invoked by the workflow.
The parameter file can also contain mapping parameters and variables and session parameters for sessions in the workflow, as well as service and service process variables for the service process that runs the workflow. When starting the DTM, the PowerCenter Integration Service process passes the parameter file name to the DTM.
Create the PowerCenter Workflow Log
The PowerCenter Integration Service process creates a log for the PowerCenter workflow. The workflow log contains a history of the workflow run, including initialization, workflow task status, and error messages. You can use information in the workflow log in conjunction with the PowerCenter Integration Service log and session log to troubleshoot system, workflow, or session problems.
Run the PowerCenter Workflow Tasks
The PowerCenter Integration Service process runs workflow tasks according to the conditional links connecting the tasks. Links define the order of execution for workflow tasks. When a task in the workflow completes, the PowerCenter Integration Service process evaluates the completed task according to specified conditions, such as success or failure. Based on the result of the evaluation, the PowerCenter Integration Service process runs successive links and tasks.
Run the PowerCenter Workflows Across the Nodes in a Grid
When you run a PowerCenter Integration Service on a grid, the service processes run workflow tasks across the nodes of the grid. The domain designates one service process as the master service process. The master service process monitors the worker service processes running on separate nodes. The worker service processes run workflows across the nodes in a grid.
Start the DTM Process
When the workflow reaches a session, the PowerCenter Integration Service process starts the DTM process. The PowerCenter Integration Service process provides the DTM process with session and parameter file information that allows the DTM to retrieve the session and mapping metadata from the repository. When you run a session on a grid, the worker service process starts multiple DTM processes that run groups of session threads.
When you use operating system profiles, the PowerCenter Integration Services starts the DTM process with the system user account you specify in the operating system profile.
Write Historical Information
The PowerCenter Integration Service process monitors the status of workflow tasks during the workflow run. When workflow tasks start or finish, the PowerCenter Integration Service process writes historical run information to the repository. Historical run information for tasks includes start and completion times and completion status. Historical run information for sessions also includes source read statistics, target load statistics, and number of errors. You can view this information using the PowerCenter Workflow Monitor.
Send Post-Session Email
The PowerCenter Integration Service process sends post-session email if the DTM terminates abnormally. The DTM sends post-session email in all other cases.