Working Directory
Specifies the relative directory where the work generates intermediate files and output. The intermediate files are placed in a subdirectory. For the Local Scheduler or HQueue, typically $HIP is used. For other schedulers, this should be a relative directory to Local Shared Root Path and Remote Shared Root Path; this path is then appended to these root paths.
Path Mapping
Global
If the PDG Path Map exists, then it is applied to file paths.
None
Delocalizes paths using the PDG_DIR token.
Path Map Zone
When on, specifies a custom mapping zone to apply to all jobs executed by this scheduler. Otherwise, the local platforms are LINUX, MAC or WIN.
Validate Outputs When Recooking
When on, PDG validates the output files of the scheduler’s cooked work items when the graph is recooked to see if the files still exist on disk. Work items that are missing output files are then automatically dirtied and cooked again. If any work items are dirtied by parameter changes, then their cache files are also automatically invalidated. Validate Outputs When Recooking is on by default.
Check Expected Outputs on Disk
When on, PDG looks for any unexpected outputs (for example, like outputs that can result from custom output handling internal logic) that were not explicitly reported when the scheduler’s work items finished cooking. This check occurs immediately after the scheduler marks work items as cooked, and expected outputs that were reported normally are not checked. If PDG finds any files that are different from the expected outputs, then they are automatically added as real output files.
Limit Jobs
When enabled, sets the maximum number of jobs that can be submitted by the scheduler at the same time.
For farm schedulers like Tractor or HQueue, this parameter can be used to limit the total number of jobs submitted to the render farm itself. Setting this parameter can help limit the load on the render farm, especially when the PDG graph has a large number of small tasks.
Tick Period
Sets the minimum time (in seconds) between calls to the onTick callback.
Max Items Per Tick
Sets the maximum number of ready item onSchedule callbacks between ticks.
Override Port Range
When on, overrides the callback server’s default port range.
Callback Port Range
Specifies the callback server’s port range values to use when overriding the default values.
Network Requirements ¶
As part of the cook, a message queue (MQ) job is submitted. This job is used to communicate information from executing jobs back to the submitting machine. For this reason, your farm machines must be able to resolve the hostnames of other farm machines.
Tip
This is as simple as editing the /etc/hosts (Linux / macOS) or C:\Windows\System32\Drivers\etc\hosts (Windows).
In addition, farm machines must not have firewalls between them, or you need to use the Task Callback Port parameter to specify the open port to use.
When the cook starts, the submitting machine connects to the farm machine that is running the MQ job. So farm machines also must not have firewalls between them and the submitting machine, or you need to use the Relay Port parameter to specify the open port to use.
Enable Server
When on, turns on the data layer server for the TOP job that will cook on the farm. This allows PilotPDG or other WebSocket clients to connect to the cooking job remotely to view the state of PDG.
Server Port
Determines which server port to use for the data layer server.
This parameter is only available when Enable Server is on.
Automatic
A free TCP port to use for the data layer server chosen by the node.
Custom
A custom TCP port to use for the data layer server specified by the user.
This is useful when there is a firewall between the farm machine and the monitoring machine.
Auto Connect
When on, the scheduler will try to send a command to create a remote visualizer when the job starts. If successful, then a remote graph is created and is automatically connected to the server executing the job. The client submitting the job must be visible to the server running the job or the connection will fail.
This parameter is only available when Enable Server is on.
Remote Graph Name
The name of the Remote Graph visualizer node created when Auto Connect is enabled.
When Finished
Determines what to do when the TOP Cook finishes. This allows the TOP Cook job to continue running after the graph cook completes so that it can be inspected by a wrangler using a Data Layer viewer. For example, with When Finished you can retry a failed work item without restarting its whole job.
Terminate
Exit the job as normal.
Keep Open If Error
Keep the job running only if there is an error detected. You will need to kill the job manually.
Keep Open
Keep the job running. You will need to kill the job manually.
Block on Failed Work Items
When on, if there are any failed work items on the scheduler, then the cook is blocked from completing and the PDG graph cook is prevented from ending. This allows you to manually retry your failed work items. You can cancel the scheduler’s cook when it is blocked by failed work items by pressing the ESC key, clicking the Cancels the current cook button in the TOP tasks bar, or by using the cancel API method.
Auto retry downstream tasks
When on, if a parent tasks is retried manually, then its child tasks will also be retried. This parameter is only available when Block on Failed Work Items is turned on.
Hython
Determines which Houdini Python interpreter (hython) is used for your Houdini jobs. You can also specify this hython in a command using the PDG_HYTHON token.
Default
Use the default hython interpreter that is installed with Houdini.
Custom
Use the executable path specified by the Hython Executable parameter.
Hython Executable
This parameter is only available when Hython is set to Custom.
The full path to the hython executable to use for your Houdini jobs.
Load Item Data From
Determines how jobs processed by this scheduler should load work item attributes and data.
Temporary JSON File
The scheduler writes out a .json file for each work item to the PDG temporary file directory. This option is selected by default.
RPC Message
The scheduler’s running work items request attributes and data over RPC. If the scheduler is a farm scheduler, then the job scripts running on the farm will also request item data from the submitter when creating their out-of-process work item objects.
This parameter option removes the need to write data files to disk and is useful when your local and remote machines do not share a file system.
Delete Temp Dir
Determines when PDG should automatically delete the temporary file directory associated with the scheduler.
Never
PDG never automatically deletes the temp file directory.
When Scheduler is Deleted
PDG automatically deletes the temp file directory when the scheduler is deleted or when Houdini is closed.
When Cook Completes
PDG automatically deletes the temp file directory each time a cook completes.
Compress Work Item Data
When on, PDG compresses the work item .json files when writing them to disk.
This parameter is only available when Load Item Data From is set to Temporary JSON File.
Ignore RPC Errors
Determines whether RPC errors should cause out of process jobs to fail.
Never
RPC connection errors will cause work items to fail.
When Cooking Batches
RPC connection errors are ignored for batch work items, which typically make a per-frame RPC back to PDG to report output files and communicate sub item status. This option prevents long-running simulations from being killed on the farm, if the submitter Houdini session crashes or becomes unresponsive.
Always
RPC connection errors will never cause a work item to fail. Note that if a work item can’t communicate with the scheduler, it will be unable to report output files, attributes or its cook status back to the PDG graph.
Max RPC Errors
The maximum number of RPC failures that can occur before RPC is disabled in an out of process job.
Connection Timeout
The number of seconds to wait when an out of process jobs makes an RPC connection to the main PDG graph, before assuming the connection failed.
Connection Retries
The number of times to retry a failed RPC call made by an out of process job.
Retry Backoff
When Connection Retries is greater than 0, this parameter determines how much time should be spent between consecutive retries.
Batch Poll Rate
Determines how quickly an out of process batch work item should poll the main Houdini session for dependency status updates, if the batch is configured to cook when it’s first frame of work is ready. This has no impact on other types of batch work items.
Release Job Slot When Polling
Determines whether or not the scheduler should decrement the number of active workers when a batch is polling for dependency updates.
