masterType property

Specifies the type of virtual machine to use for your training job's master worker.

You must specify this field when scaleTier is set to CUSTOM. You can use certain Compute Engine machine types directly in this field. See the [list of compatible Compute Engine machine types](/ai-platform/training/docs/machine-types#compute-engine-machine-types). Alternatively, you can use the certain legacy machine types in this field. See the [list of legacy machine types](/ai-platform/training/docs/machine-types#legacy-machine-types). Finally, if you want to use a TPU for training, specify cloud_tpu in this field. Learn more about the [special configuration options for training with TPUs](/ai-platform/training/docs/using-tpus#configuring_a_custom_tpu_machine).

Optional.