IBM Spectrum LSF

This contains the TorchX LSF scheduler which can be used to run TorchX components on a LSF cluster.

This scheduler is in prototype stage and may change without notice. If you run into any issues or have feedback please submit an issue.

Prerequisites

You’ll need either an existing LSF cluster to run your jobs or for individuals you can install LSF Community Edition.

See the LSF documentation for more details: https://www.ibm.com/docs/en/cloud-private/3.2.x?topic=paks-spectrum-lsf-community-edition

class torchx.schedulers.lsf_scheduler.LsfScheduler(session_name: str)

Bases: Scheduler[LsfOpts]

Example: hello_world

$ torchx run -s lsf -cfg jobdir=/mnt/data/torchx utils.echo --image alpine:latest --msg hello_world --num_replicas 3
...

Example: Gloo

$ cp dist_app.py /mnt/data/dist/
$ torchx run -s lsf -cfg "jobdir=/mnt/data/torchx,host_network=True" dist.ddp -j 2x2 --gpu 2           --script /data/dist_app.py --mount "type=bind,src=/mnt/data/dist,dst=/data"
...

Config Options

    usage:
        [lsf_queue=LSF_QUEUE],[jobdir=JOBDIR],[container_workdir=CONTAINER_WORKDIR],[host_network=HOST_NETWORK],[shm_size=SHM_SIZE]

    optional arguments:
        lsf_queue=LSF_QUEUE (str, None)
            queue name to submit jobs
        jobdir=JOBDIR (str, None)
            The directory to place the job code and outputs. The directory must not exist and will be created.
        container_workdir=CONTAINER_WORKDIR (str, None)
            working directory in container jobs
        host_network=HOST_NETWORK (bool, False)
            True if using the host network for jobs
        shm_size=SHM_SIZE (str, 64m)
            size of shared memory (/dev/shm) for jobs

Compatibility

Feature	Scheduler Support
Fetch Logs	✔️
Distributed Jobs	✔️
Cancel Job	✔️
Describe Job	LsfScheduler will return job.
Workspaces / Patching	❌
Mounts	✔️
Elasticity	❌

TOFIX

• On host_network=False, tasks cannot reoslve static names such as /etc/hosts (containers cannot reach it without host network)

• Image downloads should be separated jobs

describe(app_id: str) → Optional[DescribeAppResponse]

Describes the specified application.

Returns:

AppDef description or None if the app does not exist.

list() → List[ListAppResponse]

For apps launched on the scheduler, this API returns a list of ListAppResponse objects each of which have app id and its status. Note: This API is in prototype phase and is subject to change.

log_iter(app_id: str, role_name: str, k: int = 0, regex: Optional[str] = None, since: Optional[datetime] = None, until: Optional[datetime] = None, should_tail: bool = False, streams: Optional[Stream] = None) → Iterable[str]

Returns an iterator to the log lines of the k``th replica of the ``role. The iterator ends when all qualifying log lines have been read.

If the scheduler supports time-based cursors fetching log lines for custom time ranges, then the since, until fields are honored, otherwise they are ignored. Not specifying since and until is equivalent to getting all available log lines. If the until is empty, then the iterator behaves like tail -f, following the log output until the job reaches a terminal state.

The exact definition of what constitutes a log is scheduler specific. Some schedulers may consider stderr or stdout as the log, others may read the logs from a log file.

Behaviors and assumptions:

1. Produces an undefined-behavior if called on an app that does not exist The caller should check that the app exists using exists(app_id) prior to calling this method.

2. Is not stateful, calling this method twice with same parameters returns a new iterator. Prior iteration progress is lost.

3. Does not always support log-tailing. Not all schedulers support live log iteration (e.g. tailing logs while the app is running). Refer to the specific scheduler’s documentation for the iterator’s behavior.

3.1 If the scheduler supports log-tailing, it should be controlled

by should_tail parameter.

4. Does not guarantee log retention. It is possible that by the time this method is called, the underlying scheduler may have purged the log records for this application. If so this method raises an arbitrary exception.

5. If should_tail is True, the method only raises a StopIteration exception when the accessible log lines have been fully exhausted and the app has reached a final state. For instance, if the app gets stuck and does not produce any log lines, then the iterator blocks until the app eventually gets killed (either via timeout or manually) at which point it raises a StopIteration.

   If should_tail is False, the method raises StopIteration when there are no more logs.

6. Need not be supported by all schedulers.

7. Some schedulers may support line cursors by supporting __getitem__ (e.g. iter[50] seeks to the 50th log line).

8. Whitespace is preserved, each new line should include \n. To

   support interactive progress bars the returned lines don’t need to include \n but should then be printed without a newline to correctly handle \r carriage returns.

Parameters:

streams – The IO output streams to select. One of: combined, stdout, stderr. If the selected stream isn’t supported by the scheduler it will throw an ValueError.

Returns:

An Iterator over log lines of the specified role replica

Raises:

NotImplementedError – if the scheduler does not support log iteration

schedule(dryrun_info: AppDryRunInfo[LsfBsub]) → str

Same as submit except that it takes an AppDryRunInfo. Implementers are encouraged to implement this method rather than directly implementing submit since submit can be trivially implemented by:

dryrun_info = self.submit_dryrun(app, cfg)
return schedule(dryrun_info)

class torchx.schedulers.lsf_scheduler.LsfBsub(jobdir: Union[str, NoneType], app_id: str, app: torchx.specs.api.AppDef, cfg: torchx.schedulers.lsf_scheduler.LsfOpts, cmd: List[str])

Reference

torchx.schedulers.lsf_scheduler.create_scheduler(session_name: str, **kwargs: Any) → LsfScheduler