[Retrieval-augmented generation (RAG)](https://en.wikipedia.org/wiki/Retrieval-augmented_generation) is a technique that enables generative artificial intelligence (Gen AI) models to retrieve and incorporate new information. It modifies interactions with a large language model (LLM) so that the model responds to user queries with reference to a specified set of documents, using this information to supplement information from its pre-existing training data. This allows LLMs to use domain-specific and/or updated information. Use cases include providing chatbot access to internal company data or generating responses based on authoritative sources.
[Retrieval-augmented generation (RAG)](https://en.wikipedia.org/wiki/Retrieval-augmented_generation) is a technique that enables generative artificial intelligence (Gen AI) models to retrieve and incorporate new information. It modifies interactions with a large language model (LLM) so that the model responds to user queries with reference to a specified set of documents, using this information to supplement information from its pre-existing training data. This allows LLMs to use domain-specific and/or updated information. Use cases include providing chatbot access to internal company data or generating responses based on authoritative sources.
vLLM can be **run and scaled to multiple service replicas on clouds and Kubernetes** with [SkyPilot](https://github.com/skypilot-org/skypilot), an open-source framework for running LLMs on any cloud. More examples for various open models, such as Llama-3, Mixtral, etc, can be found in [SkyPilot AI gallery](https://skypilot.readthedocs.io/en/latest/gallery/index.html).
vLLM can be **run and scaled to multiple service replicas on clouds and Kubernetes** with [SkyPilot](https://github.com/skypilot-org/skypilot), an open-source framework for running LLMs on any cloud. More examples for various open models, such as Llama-3, Mixtral, etc, can be found in [SkyPilot AI gallery](https://skypilot.readthedocs.io/en/latest/gallery/index.html).
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@@ -83,7 +82,11 @@ Check the output of the command. There will be a shareable gradio link (like the
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@@ -83,7 +82,11 @@ Check the output of the command. There will be a shareable gradio link (like the
**Optional**: Serve the 70B model instead of the default 8B and use more GPU:
**Optional**: Serve the 70B model instead of the default 8B and use more GPU:
<summary>Click to see the full recipe YAML</summary>
<summary>Click to see the full recipe YAML</summary>
:::
```yaml
```yaml
service:
service:
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@@ -153,14 +154,14 @@ run: |
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@@ -153,14 +154,14 @@ run: |
2>&1 | tee api_server.log
2>&1 | tee api_server.log
```
```
:::{raw} html
</details>
</details>
:::
Start the serving the Llama-3 8B model on multiple replicas:
Start the serving the Llama-3 8B model on multiple replicas:
```console
```console
HF_TOKEN="your-huggingface-token" sky serve up -n vllm serving.yaml --env HF_TOKEN
HF_TOKEN="your-huggingface-token" \
sky serve up -n vllm serving.yaml \
--env HF_TOKEN
```
```
Wait until the service is ready:
Wait until the service is ready:
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@@ -169,10 +170,8 @@ Wait until the service is ready:
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@@ -169,10 +170,8 @@ Wait until the service is ready:
watch -n10 sky serve status vllm
watch -n10 sky serve status vllm
```
```
:::{raw} html
<details>
<details>
<summary>Example outputs:</summary>
<summary>Example outputs:</summary>
:::
```console
```console
Services
Services
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@@ -185,9 +184,7 @@ vllm 1 1 xx.yy.zz.121 18 mins ago 1x GCP([Spot]{'L4': 1}) R
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@@ -185,9 +184,7 @@ vllm 1 1 xx.yy.zz.121 18 mins ago 1x GCP([Spot]{'L4': 1}) R
vllm 2 1 xx.yy.zz.245 18 mins ago 1x GCP([Spot]{'L4': 1}) READY us-east4
vllm 2 1 xx.yy.zz.245 18 mins ago 1x GCP([Spot]{'L4': 1}) READY us-east4
```
```
:::{raw} html
</details>
</details>
:::
After the service is READY, you can find a single endpoint for the service and access the service with the endpoint:
After the service is READY, you can find a single endpoint for the service and access the service with the endpoint:
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@@ -223,10 +220,8 @@ service:
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@@ -223,10 +220,8 @@ service:
This will scale the service up to when the QPS exceeds 2 for each replica.
This will scale the service up to when the QPS exceeds 2 for each replica.
:::{raw} html
<details>
<details>
<summary>Click to see the full recipe YAML</summary>
<summary>Click to see the full recipe YAML</summary>
:::
```yaml
```yaml
service:
service:
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@@ -275,9 +270,7 @@ run: |
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@@ -275,9 +270,7 @@ run: |
2>&1 | tee api_server.log
2>&1 | tee api_server.log
```
```
:::{raw} html
</details>
</details>
:::
To update the service with the new config:
To update the service with the new config:
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@@ -295,10 +288,8 @@ sky serve down vllm
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@@ -295,10 +288,8 @@ sky serve down vllm
It is also possible to access the Llama-3 service with a separate GUI frontend, so the user requests send to the GUI will be load-balanced across replicas.
It is also possible to access the Llama-3 service with a separate GUI frontend, so the user requests send to the GUI will be load-balanced across replicas.
[Streamlit](https://github.com/streamlit/streamlit) lets you transform Python scripts into interactive web apps in minutes, instead of weeks. Build dashboards, generate reports, or create chat apps.
[Streamlit](https://github.com/streamlit/streamlit) lets you transform Python scripts into interactive web apps in minutes, instead of weeks. Build dashboards, generate reports, or create chat apps.
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@@ -32,11 +33,11 @@ pip install streamlit openai
streamlit run streamlit_openai_chatbot_webserver.py
streamlit run streamlit_openai_chatbot_webserver.py
#or specify the VLLM_API_BASE or VLLM_API_KEY
#or specify the VLLM_API_BASE or VLLM_API_KEY
VLLM_API_BASE="http://vllm-server-host:vllm-server-port/v1" streamlit run streamlit_openai_chatbot_webserver.py
The [Triton Inference Server](https://github.com/triton-inference-server) hosts a tutorial demonstrating how to quickly deploy a simple [facebook/opt-125m](https://huggingface.co/facebook/opt-125m) model using vLLM. Please see [Deploying a vLLM model in Triton](https://github.com/triton-inference-server/tutorials/blob/main/Quick_Deploy/vLLM/README.md#deploying-a-vllm-model-in-triton) for more details.
The [Triton Inference Server](https://github.com/triton-inference-server) hosts a tutorial demonstrating how to quickly deploy a simple [facebook/opt-125m](https://huggingface.co/facebook/opt-125m) model using vLLM. Please see [Deploying a vLLM model in Triton](https://github.com/triton-inference-server/tutorials/blob/main/Quick_Deploy/vLLM/README.md#deploying-a-vllm-model-in-triton) for more details.
[KubeAI](https://github.com/substratusai/kubeai) is a Kubernetes operator that enables you to deploy and manage AI models on Kubernetes. It provides a simple and scalable way to deploy vLLM in production. Functionality such as scale-from-zero, load based autoscaling, model caching, and much more is provided out of the box with zero external dependencies.
[KubeAI](https://github.com/substratusai/kubeai) is a Kubernetes operator that enables you to deploy and manage AI models on Kubernetes. It provides a simple and scalable way to deploy vLLM in production. Functionality such as scale-from-zero, load based autoscaling, model caching, and much more is provided out of the box with zero external dependencies.
[llmaz](https://github.com/InftyAI/llmaz) is an easy-to-use and advanced inference platform for large language models on Kubernetes, aimed for production use. It uses vLLM as the default model serving backend.
[llmaz](https://github.com/InftyAI/llmaz) is an easy-to-use and advanced inference platform for large language models on Kubernetes, aimed for production use. It uses vLLM as the default model serving backend.
Deploying vLLM on Kubernetes is a scalable and efficient way to serve machine learning models. This guide walks you through deploying vLLM using the [vLLM production stack](https://github.com/vllm-project/production-stack). Born out of a Berkeley-UChicago collaboration, [vLLM production stack](https://github.com/vllm-project/production-stack) is an officially released, production-optimized codebase under the [vLLM project](https://github.com/vllm-project), designed for LLM deployment with:
Deploying vLLM on Kubernetes is a scalable and efficient way to serve machine learning models. This guide walks you through deploying vLLM using the [vLLM production stack](https://github.com/vllm-project/production-stack). Born out of a Berkeley-UChicago collaboration, [vLLM production stack](https://github.com/vllm-project/production-stack) is an officially released, production-optimized codebase under the [vLLM project](https://github.com/vllm-project), designed for LLM deployment with:
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@@ -114,7 +115,7 @@ To remove the deployment, run:
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@@ -114,7 +115,7 @@ To remove the deployment, run:
Deploying vLLM on Kubernetes is a scalable and efficient way to serve machine learning models. This guide walks you through deploying vLLM using native Kubernetes.
Deploying vLLM on Kubernetes is a scalable and efficient way to serve machine learning models. This guide walks you through deploying vLLM using native Kubernetes.
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@@ -8,6 +9,7 @@ Deploying vLLM on Kubernetes is a scalable and efficient way to serve machine le
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@@ -8,6 +9,7 @@ Deploying vLLM on Kubernetes is a scalable and efficient way to serve machine le
*[Deployment with GPUs](#deployment-with-gpus)
*[Deployment with GPUs](#deployment-with-gpus)
Alternatively, you can deploy vLLM to Kubernetes using any of the following:
Alternatively, you can deploy vLLM to Kubernetes using any of the following:
*[Helm](frameworks/helm.md)
*[Helm](frameworks/helm.md)
*[InftyAI/llmaz](integrations/llmaz.md)
*[InftyAI/llmaz](integrations/llmaz.md)
*[KServe](integrations/kserve.md)
*[KServe](integrations/kserve.md)
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@@ -19,9 +21,8 @@ Alternatively, you can deploy vLLM to Kubernetes using any of the following:
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@@ -19,9 +21,8 @@ Alternatively, you can deploy vLLM to Kubernetes using any of the following:
## Deployment with CPUs
## Deployment with CPUs
:::{note}
!!! note
The use of CPUs here is for demonstration and testing purposes only and its performance will not be on par with GPUs.
The use of CPUs here is for demonstration and testing purposes only and its performance will not be on par with GPUs.
:::
First, create a Kubernetes PVC and Secret for downloading and storing Hugging Face model:
First, create a Kubernetes PVC and Secret for downloading and storing Hugging Face model:
To avoid accidentally passing incorrect arguments, the constructor is now keyword-only. This ensures that the constructor will raise an error if old configurations are passed. vLLM developers have already made this change for all models within vLLM. For out-of-tree registered models, developers need to update their models, for example by adding shim code to adapt the old constructor signature to the new one:
To avoid accidentally passing incorrect arguments, the constructor is now keyword-only. This ensures that the constructor will raise an error if old configurations are passed. vLLM developers have already made this change for all models within vLLM. For out-of-tree registered models, developers need to update their models, for example by adding shim code to adapt the old constructor signature to the new one:
The core idea of [PagedAttention](https://blog.vllm.ai/2023/06/20/vllm.html) is to partition the KV cache of each request into KV Blocks. Each block contains the attention keys and values for a fixed number of tokens. The PagedAttention algorithm allows these blocks to be stored in non-contiguous physical memory so that we can eliminate memory fragmentation by allocating the memory on demand.
The core idea of [PagedAttention](https://blog.vllm.ai/2023/06/20/vllm.html) is to partition the KV cache of each request into KV Blocks. Each block contains the attention keys and values for a fixed number of tokens. The PagedAttention algorithm allows these blocks to be stored in non-contiguous physical memory so that we can eliminate memory fragmentation by allocating the memory on demand.
This document describes how vLLM integrates with HuggingFace libraries. We will explain step by step what happens under the hood when we run `vllm serve`.
This document describes how vLLM integrates with HuggingFace libraries. We will explain step by step what happens under the hood when we run `vllm serve`.
Let's say we want to serve the popular QWen model by running `vllm serve Qwen/Qwen2-7B`.
Let's say we want to serve the popular QWen model by running `vllm serve Qwen/Qwen2-7B`.
1. The `model` argument is `Qwen/Qwen2-7B`. vLLM determines whether this model exists by checking for the corresponding config file `config.json`. See this [code snippet](https://github.com/vllm-project/vllm/blob/10b67d865d92e376956345becafc249d4c3c0ab7/vllm/transformers_utils/config.py#L162-L182) for the implementation. Within this process:
1. The `model` argument is `Qwen/Qwen2-7B`. vLLM determines whether this model exists by checking for the corresponding config file `config.json`. See this [code snippet](https://github.com/vllm-project/vllm/blob/10b67d865d92e376956345becafc249d4c3c0ab7/vllm/transformers_utils/config.py#L162-L182) for the implementation. Within this process:
- If the `model` argument corresponds to an existing local path, vLLM will load the config file directly from this path.
- If the `model` argument corresponds to an existing local path, vLLM will load the config file directly from this path.
- If the `model` argument is a HuggingFace model ID consisting of a username and model name, vLLM will first try to use the config file from the HuggingFace local cache, using the `model` argument as the model name and the `--revision` argument as the revision. See [their website](https://huggingface.co/docs/huggingface_hub/en/package_reference/environment_variables#hfhome) for more information on how the HuggingFace cache works.
- If the `model` argument is a HuggingFace model ID consisting of a username and model name, vLLM will first try to use the config file from the HuggingFace local cache, using the `model` argument as the model name and the `--revision` argument as the revision. See [their website](https://huggingface.co/docs/huggingface_hub/en/package_reference/environment_variables#hfhome) for more information on how the HuggingFace cache works.
- If the `model` argument is a HuggingFace model ID but it is not found in the cache, vLLM will download the config file from the HuggingFace model hub. Refer to [this function](https://github.com/vllm-project/vllm/blob/10b67d865d92e376956345becafc249d4c3c0ab7/vllm/transformers_utils/config.py#L91) for the implementation. The input arguments include the `model` argument as the model name, the `--revision` argument as the revision, and the environment variable `HF_TOKEN` as the token to access the model hub. In our case, vLLM will download the [config.json](https://huggingface.co/Qwen/Qwen2-7B/blob/main/config.json) file.
- If the `model` argument is a HuggingFace model ID but it is not found in the cache, vLLM will download the config file from the HuggingFace model hub. Refer to [this function](https://github.com/vllm-project/vllm/blob/10b67d865d92e376956345becafc249d4c3c0ab7/vllm/transformers_utils/config.py#L91) for the implementation. The input arguments include the `model` argument as the model name, the `--revision` argument as the revision, and the environment variable `HF_TOKEN` as the token to access the model hub. In our case, vLLM will download the [config.json](https://huggingface.co/Qwen/Qwen2-7B/blob/main/config.json) file.
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@@ -15,7 +15,6 @@ Let's say we want to serve the popular QWen model by running `vllm serve Qwen/Qw
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@@ -15,7 +15,6 @@ Let's say we want to serve the popular QWen model by running `vllm serve Qwen/Qw
2. After confirming the existence of the model, vLLM loads its config file and converts it into a dictionary. See this [code snippet](https://github.com/vllm-project/vllm/blob/10b67d865d92e376956345becafc249d4c3c0ab7/vllm/transformers_utils/config.py#L185-L186) for the implementation.
2. After confirming the existence of the model, vLLM loads its config file and converts it into a dictionary. See this [code snippet](https://github.com/vllm-project/vllm/blob/10b67d865d92e376956345becafc249d4c3c0ab7/vllm/transformers_utils/config.py#L185-L186) for the implementation.
3. Next, vLLM [inspects](https://github.com/vllm-project/vllm/blob/10b67d865d92e376956345becafc249d4c3c0ab7/vllm/transformers_utils/config.py#L189) the `model_type` field in the config dictionary to [generate](https://github.com/vllm-project/vllm/blob/10b67d865d92e376956345becafc249d4c3c0ab7/vllm/transformers_utils/config.py#L190-L216) the config object to use. There are some `model_type` values that vLLM directly supports; see [here](https://github.com/vllm-project/vllm/blob/10b67d865d92e376956345becafc249d4c3c0ab7/vllm/transformers_utils/config.py#L48) for the list. If the `model_type` is not in the list, vLLM will use [AutoConfig.from_pretrained](https://huggingface.co/docs/transformers/en/model_doc/auto#transformers.AutoConfig.from_pretrained) to load the config class, with `model`, `--revision`, and `--trust_remote_code` as the arguments. Please note that:
3. Next, vLLM [inspects](https://github.com/vllm-project/vllm/blob/10b67d865d92e376956345becafc249d4c3c0ab7/vllm/transformers_utils/config.py#L189) the `model_type` field in the config dictionary to [generate](https://github.com/vllm-project/vllm/blob/10b67d865d92e376956345becafc249d4c3c0ab7/vllm/transformers_utils/config.py#L190-L216) the config object to use. There are some `model_type` values that vLLM directly supports; see [here](https://github.com/vllm-project/vllm/blob/10b67d865d92e376956345becafc249d4c3c0ab7/vllm/transformers_utils/config.py#L48) for the list. If the `model_type` is not in the list, vLLM will use [AutoConfig.from_pretrained](https://huggingface.co/docs/transformers/en/model_doc/auto#transformers.AutoConfig.from_pretrained) to load the config class, with `model`, `--revision`, and `--trust_remote_code` as the arguments. Please note that:
- HuggingFace also has its own logic to determine the config class to use. It will again use the `model_type` field to search for the class name in the transformers library; see [here](https://github.com/huggingface/transformers/tree/main/src/transformers/models) for the list of supported models. If the `model_type` is not found, HuggingFace will use the `auto_map` field from the config JSON file to determine the class name. Specifically, it is the `AutoConfig` field under `auto_map`. See [DeepSeek](https://huggingface.co/deepseek-ai/DeepSeek-V2.5/blob/main/config.json) for an example.
- HuggingFace also has its own logic to determine the config class to use. It will again use the `model_type` field to search for the class name in the transformers library; see [here](https://github.com/huggingface/transformers/tree/main/src/transformers/models) for the list of supported models. If the `model_type` is not found, HuggingFace will use the `auto_map` field from the config JSON file to determine the class name. Specifically, it is the `AutoConfig` field under `auto_map`. See [DeepSeek](https://huggingface.co/deepseek-ai/DeepSeek-V2.5/blob/main/config.json) for an example.
- The `AutoConfig` field under `auto_map` points to a module path in the model's repository. To create the config class, HuggingFace will import the module and use the `from_pretrained` method to load the config class. This can generally cause arbitrary code execution, so it is only executed when `--trust_remote_code` is enabled.
- The `AutoConfig` field under `auto_map` points to a module path in the model's repository. To create the config class, HuggingFace will import the module and use the `from_pretrained` method to load the config class. This can generally cause arbitrary code execution, so it is only executed when `--trust_remote_code` is enabled.
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@@ -28,7 +27,6 @@ Beyond that, there are two more things vLLM depends on HuggingFace for.
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@@ -28,7 +27,6 @@ Beyond that, there are two more things vLLM depends on HuggingFace for.
1.**Tokenizer**: vLLM uses the tokenizer from HuggingFace to tokenize the input text. The tokenizer is loaded using [AutoTokenizer.from_pretrained](https://huggingface.co/docs/transformers/en/model_doc/auto#transformers.AutoTokenizer.from_pretrained) with the `model` argument as the model name and the `--revision` argument as the revision. It is also possible to use a tokenizer from another model by specifying the `--tokenizer` argument in the `vllm serve` command. Other relevant arguments are `--tokenizer-revision` and `--tokenizer-mode`. Please check HuggingFace's documentation for the meaning of these arguments. This part of the logic can be found in the [get_tokenizer](https://github.com/vllm-project/vllm/blob/127c07480ecea15e4c2990820c457807ff78a057/vllm/transformers_utils/tokenizer.py#L87) function. After obtaining the tokenizer, notably, vLLM will cache some expensive attributes of the tokenizer in [get_cached_tokenizer](https://github.com/vllm-project/vllm/blob/127c07480ecea15e4c2990820c457807ff78a057/vllm/transformers_utils/tokenizer.py#L24).
1.**Tokenizer**: vLLM uses the tokenizer from HuggingFace to tokenize the input text. The tokenizer is loaded using [AutoTokenizer.from_pretrained](https://huggingface.co/docs/transformers/en/model_doc/auto#transformers.AutoTokenizer.from_pretrained) with the `model` argument as the model name and the `--revision` argument as the revision. It is also possible to use a tokenizer from another model by specifying the `--tokenizer` argument in the `vllm serve` command. Other relevant arguments are `--tokenizer-revision` and `--tokenizer-mode`. Please check HuggingFace's documentation for the meaning of these arguments. This part of the logic can be found in the [get_tokenizer](https://github.com/vllm-project/vllm/blob/127c07480ecea15e4c2990820c457807ff78a057/vllm/transformers_utils/tokenizer.py#L87) function. After obtaining the tokenizer, notably, vLLM will cache some expensive attributes of the tokenizer in [get_cached_tokenizer](https://github.com/vllm-project/vllm/blob/127c07480ecea15e4c2990820c457807ff78a057/vllm/transformers_utils/tokenizer.py#L24).
2.**Model weight**: vLLM downloads the model weight from the HuggingFace model hub using the `model` argument as the model name and the `--revision` argument as the revision. vLLM provides the argument `--load-format` to control what files to download from the model hub. By default, it will try to load the weights in the safetensors format and fall back to the PyTorch bin format if the safetensors format is not available. We can also pass `--load-format dummy` to skip downloading the weights.
2.**Model weight**: vLLM downloads the model weight from the HuggingFace model hub using the `model` argument as the model name and the `--revision` argument as the revision. vLLM provides the argument `--load-format` to control what files to download from the model hub. By default, it will try to load the weights in the safetensors format and fall back to the PyTorch bin format if the safetensors format is not available. We can also pass `--load-format dummy` to skip downloading the weights.
- It is recommended to use the safetensors format, as it is efficient for loading in distributed inference and also safe from arbitrary code execution. See the [documentation](https://huggingface.co/docs/safetensors/en/index) for more information on the safetensors format. This part of the logic can be found [here](https://github.com/vllm-project/vllm/blob/10b67d865d92e376956345becafc249d4c3c0ab7/vllm/model_executor/model_loader/loader.py#L385). Please note that:
- It is recommended to use the safetensors format, as it is efficient for loading in distributed inference and also safe from arbitrary code execution. See the [documentation](https://huggingface.co/docs/safetensors/en/index) for more information on the safetensors format. This part of the logic can be found [here](https://github.com/vllm-project/vllm/blob/10b67d865d92e376956345becafc249d4c3c0ab7/vllm/model_executor/model_loader/loader.py#L385). Please note that:
This completes the integration between vLLM and HuggingFace.
This completes the integration between vLLM and HuggingFace.
To enable various optimizations in vLLM such as [chunked prefill][chunked-prefill] and [prefix caching][automatic-prefix-caching], we use [BaseMultiModalProcessor][vllm.multimodal.processing.BaseMultiModalProcessor] to provide the correspondence between placeholder feature tokens (e.g. `<image>`) and multi-modal inputs (e.g. the raw input image) based on the outputs of HF processor.
To enable various optimizations in vLLM such as [chunked prefill](#chunked-prefill) and [prefix caching](#automatic-prefix-caching), we use {class}`~vllm.multimodal.processing.BaseMultiModalProcessor` to provide the correspondence between placeholder feature tokens (e.g. `<image>`) and multi-modal inputs (e.g. the raw input image) based on the outputs of HF processor.
Here are the main features of [BaseMultiModalProcessor][vllm.multimodal.processing.BaseMultiModalProcessor]:
Here are the main features of {class}`~vllm.multimodal.processing.BaseMultiModalProcessor`:
## Prompt Update Detection
## Prompt Update Detection
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@@ -15,7 +16,7 @@ One of the main responsibilities of HF processor is to update the prompt with pl
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@@ -15,7 +16,7 @@ One of the main responsibilities of HF processor is to update the prompt with pl
The information about which tokens have been updated is key to finding the correspondence between placeholder feature tokens and multi-modal inputs.
The information about which tokens have been updated is key to finding the correspondence between placeholder feature tokens and multi-modal inputs.
In vLLM, this information is specified using {class}`~vllm.multimodal.processing.PromptUpdate` in {meth}`~vllm.multimodal.processing.BaseMultiModalProcessor._get_prompt_updates`. We can automatically detect whether HF has updated the prompt by checking the existence of the updated tokens.
In vLLM, this information is specified using [PromptUpdate][vllm.multimodal.processing.PromptUpdate] in [_get_prompt_updates][vllm.multimodal.processing.BaseMultiModalProcessor._get_prompt_updates]. We can automatically detect whether HF has updated the prompt by checking the existence of the updated tokens.
## Tokenized Prompt Inputs
## Tokenized Prompt Inputs
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@@ -43,22 +44,22 @@ While HF processors support text + multi-modal inputs natively, this is not so f
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@@ -43,22 +44,22 @@ While HF processors support text + multi-modal inputs natively, this is not so f
Moreover, since the tokenized text has not passed through the HF processor, we have to apply Step 3 by ourselves to keep the output tokens and multi-modal data consistent with each other.
Moreover, since the tokenized text has not passed through the HF processor, we have to apply Step 3 by ourselves to keep the output tokens and multi-modal data consistent with each other.
(mm-dummy-text)=
[](){ #mm-dummy-text }
### Dummy text
### Dummy text
We work around the first issue by requiring each model to define how to generate dummy text based on the number of multi-modal inputs, via {meth}`~vllm.multimodal.profiling.BaseDummyInputsBuilder.get_dummy_text`. This lets us generate dummy text corresponding to the multi-modal inputs and input them together to obtain the processed multi-modal data.
We work around the first issue by requiring each model to define how to generate dummy text based on the number of multi-modal inputs, via [get_dummy_text][vllm.multimodal.profiling.BaseDummyInputsBuilder.get_dummy_text]. This lets us generate dummy text corresponding to the multi-modal inputs and input them together to obtain the processed multi-modal data.
(mm-automatic-prompt-updating)=
[](){ #mm-automatic-prompt-updating }
### Automatic prompt updating
### Automatic prompt updating
We address the second issue by implementing model-agnostic code in
We address the second issue by implementing model-agnostic code in
{meth}`~vllm.multimodal.processing.BaseMultiModalProcessor._apply_prompt_updates` to automatically update the prompt with feature placeholder tokens based on the specification outputted by {meth}`~vllm.multimodal.processing.BaseMultiModalProcessor._get_prompt_updates`.
[_apply_prompt_updates][vllm.multimodal.processing.BaseMultiModalProcessor._apply_prompt_updates] to automatically update the prompt with feature placeholder tokens based on the specification outputted by [_get_prompt_updates][vllm.multimodal.processing.BaseMultiModalProcessor._get_prompt_updates].
### Summary
### Summary
With the help of dummy text and automatic prompt updating, our multi-modal processor can finally accept both text and token prompts with multi-modal data. The detailed logic is shown in {meth}`~vllm.multimodal.processing.BaseMultiModalProcessor._apply_hf_processor_main`.
With the help of dummy text and automatic prompt updating, our multi-modal processor can finally accept both text and token prompts with multi-modal data. The detailed logic is shown in [_apply_hf_processor_main][vllm.multimodal.processing.BaseMultiModalProcessor._apply_hf_processor_main].
## Processor Output Caching
## Processor Output Caching
...
@@ -66,4 +67,4 @@ Some HF processors, such as the one for Qwen2-VL, are [very slow](gh-issue:9238)
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@@ -66,4 +67,4 @@ Some HF processors, such as the one for Qwen2-VL, are [very slow](gh-issue:9238)
When new data is passed in, we first check which items are in the cache, and which ones are missing. The missing items are passed into the HF processor in a single batch and cached, before being merged with the existing items in the cache.
When new data is passed in, we first check which items are in the cache, and which ones are missing. The missing items are passed into the HF processor in a single batch and cached, before being merged with the existing items in the cache.
Since we only process the missing multi-modal data items, the number of input placeholder tokens no longer corresponds to the number of the multi-modal inputs, so they can't be passed alongside the text prompt to HF processor. Therefore, we process the text and multi-modal inputs separately, using [dummy text](#mm-dummy-text) to avoid HF errors. Since this skips HF's prompt updating code, we apply [automatic prompt updating](#mm-automatic-prompt-updating) afterwards to keep the output tokens and multi-modal data consistent with each other.
Since we only process the missing multi-modal data items, the number of input placeholder tokens no longer corresponds to the number of the multi-modal inputs, so they can't be passed alongside the text prompt to HF processor. Therefore, we process the text and multi-modal inputs separately, using [dummy text][mm-dummy-text] to avoid HF errors. Since this skips HF's prompt updating code, we apply [automatic prompt updating][mm-automatic-prompt-updating] afterwards to keep the output tokens and multi-modal data consistent with each other.
