Workflow Execution States (3.0)

All running workflows are monitored by the workflow server on the Platform. A workflow can be in any one of the following states:


The workflow state diagram

All running workflows are monitored by the workflow server on the Platform. A workflow can be in any one of the following states:

State

Description

Building

When a workflow, or any of a workflow's referenced configurations, are being re-built, for example when saving or recompiling, the workflow will be in Building state.

When a workflow is in Building state, the Configuration Monitor icon in the status bar will indicate that operations are in progress, and in the Worklow Monitor, the text Workflow is building will also be displayed. Workflows started by scheduling configurations will wait until the workflow leaves the Building state before they start.

Executed

A Workflow becomes Executed after one of the following:

StateDescription
RunningA successful execution has been completed.
UnreachableAfter the Platform re-establishes connection with the Execution Context, and the workflow has finished execution during the period of disconnection.
Manual stopA User stopped the execution.

Note!

This is a transient state, after the workflow has run, where cleanup is handled. This state is not reached if the workflow gets aborted. In the GUI, the workflow is shown as Stopped even after it has reached the idle state.

Hold

A workflow that is in the Idle state and is being imported either by the mzsh systemimport r | sr | sir | wr or by the System Importer configured to Hold Execution, enters the Hold state until the import activity is finished. The Workflow group then resumes its Idle state.

Idle

A workflow is in Idle state if there is no activity going on in the workflow. It means that workflow is not running, or, not in process of starting or stopping or not in any other state (Invalid or Hold). After execution, although the workflow is indeed idle, the state space on the display might remain as one of the following states:

StateDescription
AbortedAt least one of the workflow agents has aborted. You can track the reason for the error either by double-clicking the aborted agent, or by examining the System Log.
CompletedThe workflow has executed and gone back to the Idle state with no errors.
Not startedThe workflow has not run since the platform has started.

Invalid

The workflow configuration is erroneous. Once you correct the error, the workflow assumes the Idle state. 

Note!

The workflow cannot be executed if it is in invalid state.

Loading

The platform is uploading the workflow to the Execution Context. When the transfer is complete, the Execution Context initializes the agents. When the workflow starts running the state changes to Running.

Running

The workflow is currently executing.

Unreachable

If the Platform fails to establish connection with the EC where a workflow is executing, the workflow enters the unreachable state. When the workflow server successfully reestablishes the connection, the workflow is marked as Running, Aborted, or Executed, depending on the state that the workflow is in. An Unreachable workflow may require manual intervention if the workflow is not running any more.

Waiting

The Waiting state applies only to workflows that are included as members in a workflow group. In the Waiting state, the workflow cannot start execution due to two parameters in the workflow group configuration: The Startup Delay parameter, and the Max Simultaneous Running quota. A workflow in the Waiting state will change to Running when triggered either by a user, the scheduling criteria of its parent workflow group, or by a more distant ancestor's scheduling criteria.

Locked

Locked state is a special case that is only relevant when a batch workflow is present in multiple versions. That is, there are multiple workflows with the same name and instance id from the same workflow configuration. These can be in different versions of a package or be the same as a workflow outside any package.

This means that in case of same workflows, the packages that these workflows are part of are ignored when considering whether they are different versions of the same workflow. If this is the case (and again, only for batch workflows), then only one version is allowed to run at a time. When one version of the workflow starts, the other ones enter into the locked state until the started one completes its execution. Only then is the next version allowed to start. This allows for collection using the file sequence number service to stay consistent even if the workflow version is updated.

Viewing Abort Reasons

In most cases if a workflow has aborted, one of its agents will have the state Aborted displayed above it. Double-clicking such an agent will display a dialog containing the abort reason. The System Log also holds valid information for these cases.

In a batch workflow, a detected error causes the workflow to abort and the detected error will be shown as part of the abort reason and inserted into the System Log. A real-time workflow handles errors by only sending them to the System Log. The only time a real-time workflow will abort is when an internal error has occurred. It is therefore important to pay attention to the System Log or subscribe to workflow error events to fully understand the state of a real-time workflow.

Note!

Although a workflow has aborted, its scheduling will still be valid. Thus, if it is scheduled to execute periodically, it will be automatically started again the next time it is due to commence. This is because the abortion might be a lost connection to a network element, which could be available again later. Therefore, a periodically scheduled workflow, which has aborted, is treated as Active until it is manually deactivated.

Status details for an aborted agent

Click Show Trace; the Stack Trace Viewer opens. Use the information that it provides when consulting Global Support.

Agent States

An agent state is displayed above the agent icon in the workflow. An agent can have one of the following states:


StateDescription

Created

The agent is starting up. No data may be received during this phase. This state only exists for a short while during workflow startup.

Idle

The agent is started, awaiting data to process. This state is not available for a real-time workflow.

Running

The agent has received data and is executing.

Stopped

The agent has successfully finished processing data.

Aborted

The agent has terminated erroneously.

The error reason can be tracked either by double-clicking the agent or by examining the System Log.

Workflow Execution State

The workflow execution state provides granular information about a workflow's current execution status. In APL, there are function blocks that are called for each workflow execution state. For more information about which APL functions that may be used in each state, see Analysis(3.0) .

Real-time agents only have three different execution states, that will occur at every execution of the workflow.


Execution flow for real-time agents


The batch agents are more complex and contain additional states in order to guarantee transaction safety.


Execution flow for batch agents


State

Description

initialize

The initialize state is entered once for each invocation of the workflow. During this phase the workflow is being instantiated and all agents are set up according to their configuration.

beginBatch

This state is only applicable for batch workflows.

At every start of a new batch, the batch collection agent will emit a beginBatch call. All agents will then prepare for a new batch. This is normally done every time a new file is collected, but can differ depending on the collection agent.

consume

The agents will handle all incoming UDRs or bytearrays during the consume state.

drain

This state is only applicable for batch workflows.

When all UDRs within a batch have been executed, the agents enter the drain state. This state can be seen as a final consume state with the difference that there is no incoming UDR or bytearray. The agent may however send additional information before the endBatch state.

endBatch

This state is only applicable for batch workflows.

The collection agent will call for the endBatch state when all UDRs or the byte arrays have been transferred into the workflow. This is normally done at the file end, but is dependent on the collection agent or when a hintEndBatch call is received from any agent capable of utilizing APL code.

commit

This state is only applicable for batch workflows.

Once the batch is successfully processed or sent to Data Veracity, the commit state is entered. During this phase, all actions that concern transaction safety are executed.

deinitialize

This is the last execution state for each workflow invocation. The agents clean and release resources, such as memory and ports, and stop execution.

cancelBatch

This state is only applicable for batch workflows.

If an agent fails the processing of a batch it may emit a cancelBatch call and the setting in Workflow Properties will define how the workflow should act. For more information regarding the Workflow Properties, see Error Tab in Workflow Properties(3.0).

Note!

The execution states cancelBatch and endBatch are mutually exclusive - only one per batch can be executed.

rollback

This state is only applicable for batch workflows.

If the last execution of the workflow aborted, the agents will enter the rollback execution state right after the initialize state. The agents will recover the state prior to the failing transaction and then enter beginBatch or deinitialize depending on if there are additional batches to process.