Job.Service API

The Service class allows databases and servers to be spawned within a Toil workflow.

class Job.Service(memory=None, cores=None, disk=None, accelerators=None, preemptible=None, unitName=None)

Abstract class used to define the interface to a service.

Should be subclassed by the user to define services.

Is not executed as a job; runs within a ServiceHostJob.

__init__(memory=None, cores=None, disk=None, accelerators=None, preemptible=None, unitName=None)

Memory, core and disk requirements are specified identically to as in toil.job.Job.__init__().

abstract start(job)

Start the service.

Parameters:

job (Job) – The underlying host job that the service is being run in. Can be used to register deferred functions, or to access the fileStore for creating temporary files.

Return type:

Any

Returns:

An object describing how to access the service. The object must be pickleable and will be used by jobs to access the service (see toil.job.Job.addService()).

abstract stop(job)

Stops the service. Function can block until complete.

Parameters:

job (Job) – The underlying host job that the service is being run in. Can be used to register deferred functions, or to access the fileStore for creating temporary files.

Return type:

None

check()

Checks the service is still running.

Raises:

exceptions.RuntimeError – If the service failed, this will cause the service job to be labeled failed.

Return type:

bool

Returns:

True if the service is still running, else False. If False then the service job will be terminated, and considered a success. Important point: if the service job exits due to a failure, it should raise a RuntimeError, not return False!