Chapter 6. Serving and inferencing language models with Podman using Google TPU AI accelerators

Procedure

1. Open a terminal on your TPU server host, and log in to registry.redhat.io:

   $ podman login registry.redhat.io

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2. Pull the Red Hat AI Inference Server image by running the following command:

   $ podman pull registry.redhat.io/rhaii-early-access/vllm-tpu-rhel9:3.4.0-ea.1

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3. Optional: Verify that the TPUs are available in the host.

   1. Open a shell prompt in the Red Hat AI Inference Server container. Run the following command:

      $ podman run -it --net=host --privileged --rm --entrypoint /bin/bash registry.redhat.io/rhaii-early-access/vllm-tpu-rhel9:3.4.0-ea.1

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   2. Verify system TPU access and basic operations by running the following Python code in the container shell prompt:

      $ python3 -c "
      import jax
      import importlib.metadata
      try:
          devices = jax.devices()
          print(f'JAX devices available: {devices}')
          print(f'Number of TPU devices: {len(devices)}')
          tpu_version = importlib.metadata.version('tpu_inference')
          print(f'tpu-inference version: {tpu_version}')
          print('TPU is operational.')
      except Exception as e:
          print(f'TPU test failed: {e}')
          print('Check container image version and TPU device availability.')
      "

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      Example output:

      JAX devices available: [TpuDevice(id=0, process_index=0, coords=(0,0,0), core_on_chip=0), TpuDevice(id=1, process_index=0, coords=(1,0,0), core_on_chip=0), TpuDevice(id=2, process_index=0, coords=(0,1,0), core_on_chip=0), TpuDevice(id=3, process_index=0, coords=(1,1,0), core_on_chip=0)]
      Number of TPU devices: 4
      tpu-inference version: 0.13.2
      TPU is operational.

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   3. Exit the shell prompt.

      $ exit

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4. Create a volume and mount it into the container. Adjust the container permissions so that the container can use it.

   $ mkdir ./.cache/rhaii

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   $ chmod g+rwX ./.cache/rhaii

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5. Add the HF_TOKEN Hugging Face token to the private.env file.

   $ echo "export HF_TOKEN=<huggingface_token>" > private.env

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6. Append the HF_HOME variable to the private.env file.

   $ echo "export HF_HOME=./.cache/rhaii" >> private.env

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   Source the private.env file.

   $ source private.env

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7. Start the AI Inference Server container image:

   $ podman run --rm -it \
     --name vllm-tpu \
     --network=host \
     --privileged \
     -v /dev/shm:/dev/shm \
     -e HF_TOKEN=$HF_TOKEN \
     -e HF_HUB_OFFLINE=0 \
     -v ./.cache/rhaii:/opt/app-root/src/.cache \
     registry.redhat.io/rhaii-early-access/vllm-tpu-rhel9:3.4.0-ea.1 \
     --model Qwen/Qwen2.5-1.5B-Instruct \
     --tensor-parallel-size 1 \
     --max-model-len=256 \
     --host=0.0.0.0 \
     --port=8000

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   Where:

   --tensor-parallel-size 1

   Specifies the number of TPUs to use for tensor parallelism. Set this value to match the number of available TPUs.

   --max-model-len=256

   Specifies the maximum model context length. For optimal performance, set this value as low as your workload allows.