--- license: gemma pipeline_tag: text-classification tags: - transformers - sentence-transformers language: - multilingual --- # Reranker **More details please refer to our Github: [FlagEmbedding](https://github.com/FlagOpen/FlagEmbedding/tree/master).** - [Model List](#model-list) - [Usage](#usage) - [Fine-tuning](#fine-tune) - [Evaluation](#evaluation) - [Citation](#citation) Different from embedding model, reranker uses question and document as input and directly output similarity instead of embedding. You can get a relevance score by inputting query and passage to the reranker. And the score can be mapped to a float value in [0,1] by sigmoid function. Here, we introduce a lightweight reranker **bge-reranker-v2.5-gemma2-lightweight**, which is a multilingual model trained based on gemma2-9b. By integrating token compression capabilities and layerwise reduction, the model can maintain outstanding performance while saving significant resources. Our model primarily demonstrates the following capabilities: - Lightweight: The model can be made lightweight through token compression, layerwise reduction, or a combination of both. - Outstanding performance: The model has achieved new state-of-the-art (SOTA) performance on both BEIR and MIRACL. We will release a technical report about lightweight reranker soon with more details. ## Model List | Model | Base model | Language | layerwise | compress ratio | compress layers | feature | |:--------------------------------------------------------------------------|:--------:|:-----------------------------------------------------------------------------------------------------------------------------------:|:----------------------------------------------------------------------------------------------:|:----------------------------------------------------------------------------------------------:|:----------------------------------------------------------------------------------------------:|------------------------------------------------------------------------------------------------| | [BAAI/bge-reranker-base](https://huggingface.co/BAAI/bge-reranker-base) | [xlm-roberta-base](https://huggingface.co/xlm-roberta-base) | Chinese and English | - | - | - | Lightweight reranker model, easy to deploy, with fast inference. | | [BAAI/bge-reranker-large](https://huggingface.co/BAAI/bge-reranker-large) | [xlm-roberta-large](https://huggingface.co/FacebookAI/xlm-roberta-large) | Chinese and English | - | - | - | Lightweight reranker model, easy to deploy, with fast inference. | | [BAAI/bge-reranker-v2-m3](https://huggingface.co/BAAI/bge-reranker-v2-m3) | [bge-m3](https://huggingface.co/BAAI/bge-m3) | Multilingual | - | - | - | Lightweight reranker model, possesses strong multilingual capabilities, easy to deploy, with fast inference. | | [BAAI/bge-reranker-v2-gemma](https://huggingface.co/BAAI/bge-reranker-v2-gemma) | [gemma-2b](https://huggingface.co/google/gemma-2b) | Multilingual | - | - | - | Suitable for multilingual contexts, performs well in both English proficiency and multilingual capabilities. | | [BAAI/bge-reranker-v2-minicpm-layerwise](https://huggingface.co/BAAI/bge-reranker-v2-minicpm-layerwise) | [MiniCPM-2B-dpo-bf16](https://huggingface.co/openbmb/MiniCPM-2B-dpo-bf16) | Multilingual | 8-40 | - | - | Suitable for multilingual contexts, performs well in both English and Chinese proficiency, allows freedom to select layers for output, facilitating accelerated inference. | | [BAAI/bge-reranker-v2.5-gemma2-lightweight](https://huggingface.co/BAAI/bge-reranker-v2.5-gemma2-lightweight) | [google/gemma-2-9b](https://huggingface.co/google/gemma-2-9b) | Multilingual | 8-42 | 1, 2, 4, 8 | [8, 16, 24, 32, 40] | Suitable for multilingual contexts, performs well in both English and Chinese proficiency, allows freedom to select layers, compress ratio and compress layers for output, facilitating accelerated inference. | You can select the model according your senario and resource. - For **multilingual**, utilize [BAAI/bge-reranker-v2-m3](https://huggingface.co/BAAI/bge-reranker-v2-m3), [BAAI/bge-reranker-v2-gemma](https://huggingface.co/BAAI/bge-reranker-v2-gemma) and [BAAI/bge-reranker-v2.5-gemma2-lightweight](https://huggingface.co/BAAI/bge-reranker-v2.5-gemma2-lightweight) - For **Chinese or English**, utilize [BAAI/bge-reranker-v2-m3](https://huggingface.co/BAAI/bge-reranker-v2-m3) and [BAAI/bge-reranker-v2-minicpm-layerwise](https://huggingface.co/BAAI/bge-reranker-v2-minicpm-layerwise). - For **efficiency**, utilize [BAAI/bge-reranker-v2-m3](https://huggingface.co/BAAI/bge-reranker-v2-m3) and the low layer of [BAAI/bge-reranker-v2-minicpm-layerwise](https://huggingface.co/BAAI/bge-reranker-v2-minicpm-layerwise). - For better performance, recommand [BAAI/bge-reranker-v2-minicpm-layerwise](https://huggingface.co/BAAI/bge-reranker-v2-minicpm-layerwise) and [BAAI/bge-reranker-v2-gemma](https://huggingface.co/BAAI/bge-reranker-v2-gemma) ## Usage ### Using FlagEmbedding ``` pip install -U FlagEmbedding ``` #### For normal reranker (bge-reranker-base / bge-reranker-large / bge-reranker-v2-m3 ) Get relevance scores (higher scores indicate more relevance): ```python from FlagEmbedding import FlagReranker reranker = FlagReranker('BAAI/bge-reranker-v2-m3', use_fp16=True) # Setting use_fp16 to True speeds up computation with a slight performance degradation score = reranker.compute_score(['query', 'passage']) print(score) # -5.65234375 # You can map the scores into 0-1 by set "normalize=True", which will apply sigmoid function to the score score = reranker.compute_score(['query', 'passage'], normalize=True) print(score) # 0.003497010252573502 scores = reranker.compute_score([['what is panda?', 'hi'], ['what is panda?', 'The giant panda (Ailuropoda melanoleuca), sometimes called a panda bear or simply panda, is a bear species endemic to China.']]) print(scores) # [-8.1875, 5.26171875] # You can map the scores into 0-1 by set "normalize=True", which will apply sigmoid function to the score scores = reranker.compute_score([['what is panda?', 'hi'], ['what is panda?', 'The giant panda (Ailuropoda melanoleuca), sometimes called a panda bear or simply panda, is a bear species endemic to China.']], normalize=True) print(scores) # [0.00027803096387751553, 0.9948403768236574] ``` #### For LLM-based reranker ```python from FlagEmbedding import FlagLLMReranker reranker = FlagLLMReranker('BAAI/bge-reranker-v2-gemma', use_fp16=True) # Setting use_fp16 to True speeds up computation with a slight performance degradation # reranker = FlagLLMReranker('BAAI/bge-reranker-v2-gemma', use_bf16=True) # You can also set use_bf16=True to speed up computation with a slight performance degradation score = reranker.compute_score(['query', 'passage']) print(score) scores = reranker.compute_score([['what is panda?', 'hi'], ['what is panda?', 'The giant panda (Ailuropoda melanoleuca), sometimes called a panda bear or simply panda, is a bear species endemic to China.']]) print(scores) ``` #### For LLM-based layerwise reranker ```python from FlagEmbedding import LayerWiseFlagLLMReranker reranker = LayerWiseFlagLLMReranker('BAAI/bge-reranker-v2-minicpm-layerwise', use_fp16=True) # Setting use_fp16 to True speeds up computation with a slight performance degradation # reranker = LayerWiseFlagLLMReranker('BAAI/bge-reranker-v2-minicpm-layerwise', use_bf16=True) # You can also set use_bf16=True to speed up computation with a slight performance degradation score = reranker.compute_score(['query', 'passage'], cutoff_layers=[28]) # Adjusting 'cutoff_layers' to pick which layers are used for computing the score. print(score) scores = reranker.compute_score([['what is panda?', 'hi'], ['what is panda?', 'The giant panda (Ailuropoda melanoleuca), sometimes called a panda bear or simply panda, is a bear species endemic to China.']], cutoff_layers=[28]) print(scores) ``` #### For LLM-based lightweight reranker ```python from FlagEmbedding import LightWeightFlagLLMReranker reranker = LightWeightFlagLLMReranker('BAAI/bge-reranker-v2.5-gemma2-lightweight', use_fp16=True) # Setting use_fp16 to True speeds up computation with a slight performance degradation score = reranker.compute_score(['query', 'passage'], cutoff_layers=[28], compress_ratio=2, compress_layer=[24, 40]) # Adjusting 'cutoff_layers' to pick which layers are used for computing the score. print(score) scores = reranker.compute_score([['what is panda?', 'hi'], ['what is panda?', 'The giant panda (Ailuropoda melanoleuca), sometimes called a panda bear or simply panda, is a bear species endemic to China.']], cutoff_layers=[28], compress_ratio=2, compress_layer=[24, 40]) print(scores) ``` ### Using Huggingface transformers #### For normal reranker (bge-reranker-base / bge-reranker-large / bge-reranker-v2-m3 ) Get relevance scores (higher scores indicate more relevance): ```python import torch from transformers import AutoModelForSequenceClassification, AutoTokenizer tokenizer = AutoTokenizer.from_pretrained('BAAI/bge-reranker-v2-m3') model = AutoModelForSequenceClassification.from_pretrained('BAAI/bge-reranker-v2-m3') model.eval() pairs = [['what is panda?', 'hi'], ['what is panda?', 'The giant panda (Ailuropoda melanoleuca), sometimes called a panda bear or simply panda, is a bear species endemic to China.']] with torch.no_grad(): inputs = tokenizer(pairs, padding=True, truncation=True, return_tensors='pt', max_length=512) scores = model(**inputs, return_dict=True).logits.view(-1, ).float() print(scores) ``` #### For LLM-based reranker ```python import torch from transformers import AutoModelForCausalLM, AutoTokenizer def get_inputs(pairs, tokenizer, prompt=None, max_length=1024): if prompt is None: prompt = "Given a query A and a passage B, determine whether the passage contains an answer to the query by providing a prediction of either 'Yes' or 'No'." sep = "\n" prompt_inputs = tokenizer(prompt, return_tensors=None, add_special_tokens=False)['input_ids'] sep_inputs = tokenizer(sep, return_tensors=None, add_special_tokens=False)['input_ids'] inputs = [] for query, passage in pairs: query_inputs = tokenizer(f'A: {query}', return_tensors=None, add_special_tokens=False, max_length=max_length * 3 // 4, truncation=True) passage_inputs = tokenizer(f'B: {passage}', return_tensors=None, add_special_tokens=False, max_length=max_length, truncation=True) item = tokenizer.prepare_for_model( [tokenizer.bos_token_id] + query_inputs['input_ids'], sep_inputs + passage_inputs['input_ids'], truncation='only_second', max_length=max_length, padding=False, return_attention_mask=False, return_token_type_ids=False, add_special_tokens=False ) item['input_ids'] = item['input_ids'] + sep_inputs + prompt_inputs item['attention_mask'] = [1] * len(item['input_ids']) inputs.append(item) return tokenizer.pad( inputs, padding=True, max_length=max_length + len(sep_inputs) + len(prompt_inputs), pad_to_multiple_of=8, return_tensors='pt', ) tokenizer = AutoTokenizer.from_pretrained('BAAI/bge-reranker-v2-gemma') model = AutoModelForCausalLM.from_pretrained('BAAI/bge-reranker-v2-gemma') yes_loc = tokenizer('Yes', add_special_tokens=False)['input_ids'][0] model.eval() pairs = [['what is panda?', 'hi'], ['what is panda?', 'The giant panda (Ailuropoda melanoleuca), sometimes called a panda bear or simply panda, is a bear species endemic to China.']] with torch.no_grad(): inputs = get_inputs(pairs, tokenizer) scores = model(**inputs, return_dict=True).logits[:, -1, yes_loc].view(-1, ).float() print(scores) ``` #### For LLM-based layerwise reranker ```python import torch from transformers import AutoModelForCausalLM, AutoTokenizer def get_inputs(pairs, tokenizer, prompt=None, max_length=1024): if prompt is None: prompt = "Given a query A and a passage B, determine whether the passage contains an answer to the query by providing a prediction of either 'Yes' or 'No'." sep = "\n" prompt_inputs = tokenizer(prompt, return_tensors=None, add_special_tokens=False)['input_ids'] sep_inputs = tokenizer(sep, return_tensors=None, add_special_tokens=False)['input_ids'] inputs = [] for query, passage in pairs: query_inputs = tokenizer(f'A: {query}', return_tensors=None, add_special_tokens=False, max_length=max_length * 3 // 4, truncation=True) passage_inputs = tokenizer(f'B: {passage}', return_tensors=None, add_special_tokens=False, max_length=max_length, truncation=True) item = tokenizer.prepare_for_model( [tokenizer.bos_token_id] + query_inputs['input_ids'], sep_inputs + passage_inputs['input_ids'], truncation='only_second', max_length=max_length, padding=False, return_attention_mask=False, return_token_type_ids=False, add_special_tokens=False ) item['input_ids'] = item['input_ids'] + sep_inputs + prompt_inputs item['attention_mask'] = [1] * len(item['input_ids']) inputs.append(item) return tokenizer.pad( inputs, padding=True, max_length=max_length + len(sep_inputs) + len(prompt_inputs), pad_to_multiple_of=8, return_tensors='pt', ) tokenizer = AutoTokenizer.from_pretrained('BAAI/bge-reranker-v2-minicpm-layerwise', trust_remote_code=True) model = AutoModelForCausalLM.from_pretrained('BAAI/bge-reranker-v2-minicpm-layerwise', trust_remote_code=True, torch_dtype=torch.bfloat16) model = model.to('cuda') model.eval() pairs = [['what is panda?', 'hi'], ['what is panda?', 'The giant panda (Ailuropoda melanoleuca), sometimes called a panda bear or simply panda, is a bear species endemic to China.']] with torch.no_grad(): inputs = get_inputs(pairs, tokenizer).to(model.device) all_scores = model(**inputs, return_dict=True, cutoff_layers=[28]) all_scores = [scores[:, -1].view(-1, ).float() for scores in all_scores[0]] print(all_scores) ``` #### For LLM-based lightweight reranker ```python import torch from transformers import AutoModelForCausalLM, AutoTokenizer def last_logit_pool(logits: torch.Tensor, attention_mask: torch.Tensor) -> torch.Tensor: left_padding = (attention_mask[:, -1].sum() == attention_mask.shape[0]) if left_padding: return logits[:, -1] else: sequence_lengths = attention_mask.sum(dim=1) - 1 batch_size = logits.shape[0] return torch.stack([logits[i, sequence_lengths[i]] for i in range(batch_size)], dim=0) def get_inputs(pairs, tokenizer, prompt=None, max_length=1024): if prompt is None: prompt = "Predict whether passage B contains an answer to query A." sep = "\n" prompt_inputs = tokenizer(prompt, return_tensors=None, add_special_tokens=False)['input_ids'] sep_inputs = tokenizer(sep, return_tensors=None, add_special_tokens=False)['input_ids'] inputs = [] query_lengths = [] prompt_lengths = [] for query, passage in pairs: query_inputs = tokenizer(f'A: {query}', return_tensors=None, add_special_tokens=False, max_length=max_length * 3 // 4, truncation=True) passage_inputs = tokenizer(f'B: {passage}', return_tensors=None, add_special_tokens=False, max_length=max_length, truncation=True) item = tokenizer.prepare_for_model( [tokenizer.bos_token_id] + query_inputs['input_ids'], sep_inputs + passage_inputs['input_ids'], truncation='only_second', max_length=max_length, padding=False, return_attention_mask=False, return_token_type_ids=False, add_special_tokens=False ) item['input_ids'] = item['input_ids'] + sep_inputs + prompt_inputs item['attention_mask'] = [1] * len(item['input_ids']) inputs.append(item) query_lengths.append(len([tokenizer.bos_token_id] + query_inputs['input_ids'] + sep_inputs)) prompt_lengths.append(len(sep_inputs + prompt_inputs)) return tokenizer.pad( inputs, padding=True, max_length=max_length + len(sep_inputs) + len(prompt_inputs), pad_to_multiple_of=8, return_tensors='pt', ), query_lengths, prompt_lengths tokenizer = AutoTokenizer.from_pretrained('BAAI/bge-reranker-v2.5-gemma2-lightweight', trust_remote_code=True) tokenizer.padding_side = 'right' model = AutoModelForCausalLM.from_pretrained('BAAI/bge-reranker-v2.5-gemma2-lightweight', trust_remote_code=True) model = model.to('cuda') model.eval() pairs = [['what is panda?', 'hi'], ['what is panda?', 'The giant panda (Ailuropoda melanoleuca), sometimes called a panda bear or simply panda, is a bear species endemic to China.']] with torch.no_grad(): inputs, query_lengths, prompt_lengths = get_inputs(pairs, tokenizer) inputs = inputs.to(model.device) outputs = model(**inputs, return_dict=True, cutoff_layers=[28], compress_ratio=2, compress_layer=[24, 40], query_lengths=query_lengths, prompt_lengths=prompt_lengths) scores = [] for i in range(len(outputs.logits)): logits = last_logit_pool(outputs.logits[i], outputs.attention_masks[i]) scores.append(logits.cpu().float().tolist()) print(scores) ``` ## Evaluation - **BEIR:** | BEIR | bge-large-en-v1.5 | Bge-rearanker v2 m3 | jina-reranker-v2-base-multilingual | bge-reranker-v2.5-gemma2-lightweight | bge-reranker-v2.5-gemma2-lightweight | | :----------------: | :---------------: | :-----------------: | :--------------------------------: | :----------------------------------: | :----------------------------------: | | **Save** **Flops** | - | - | - | 60% | 0 | | **ArguAna** | 63.54 | 37.7 | 52.23 | 86.04 | 86.16 | | **ClimateFEVER** | 36.49 | 37.99 | 34.65 | 48.41 | 48.48 | | **CQA** | 42.23 | 38.24 | 40.21 | 49.18 | 48.9 | | **DBPedia** | 44.16 | 48.15 | 49.31 | 51.98 | 52.11 | | **FEVER** | 87.17 | 90.15 | 92.44 | 94.71 | 94.69 | | **FiQA2018** | 44.97 | 49.32 | 45.88 | 60.48 | 60.95 | | **HotpotQA** | 74.11 | 84.51 | 81.81 | 87.84 | 87.89 | | **MSMARCO** | 42.48 | 47.79 | 47.83 | 47.23 | 47.26 | | **NFCorpus** | 38.12 | 34.85 | 37.73 | 41.4 | 41.64 | | **NQ** | 55.04 | 69.37 | 67.35 | 75.37 | 75.58 | | **QuoraRetrieval** | 89.06 | 89.13 | 87.81 | 91.25 | 91.18 | | **SCIDOCS** | 22.62 | 18.25 | 20.21 | 23.71 | 23.87 | | **SciFact** | 74.64 | 73.08 | 76.93 | 80.5 | 80.38 | | **Touche2020** | 25.08 | 35.68 | 32.45 | 30.64 | 31.09 | | **TRECCOVID** | 74.89 | 83.39 | 80.89 | 84.26 | 84.85 | | **Mean** | 54.31 | 55.36 | 56.52 | 63.1 | **63.67** | | BEIR | e5-mistral-7b-instruct | Bge-rearanker v2 m3 | bge-reranker-v2.5-gemma-lightweight | bge-reranker-v2.5-gemma-lightweight | | :----------------: | :--------------------: | :-----------------: | :---------------------------------: | :---------------------------------: | | **Save Flops** | - | - | 60% | 0 | | **ArguAna** | 61.8 | 79.05 | 86.02 | 86.58 | | **ClimateFEVER** | 38.37 | 37.66 | 47.27 | 47.13 | | **CQA** | 42.97 | 46.16 | 49.06 | 49.53 | | **DBPedia** | 48.84 | 50.77 | 52.45 | 52.87 | | **FEVER** | 87.82 | 91.36 | 94.85 | 95.19 | | **FiQA2018** | 56.58 | 50.96 | 58.81 | 61.19 | | **HotpotQA** | 75.72 | 86.99 | 88.49 | 88.82 | | **MSMARCO** | 43.06 | 48.35 | 47.65 | 47.4 | | **NFCorpus** | 38.58 | 39.25 | 42.28 | 42.17 | | **NQ** | 63.56 | 73.44 | 75 | 76.28 | | **QuoraRetrieval** | 89.59 | 90.44 | 91.09 | 91.18 | | **SCIDOCS** | 16.3 | 20.77 | 22.2 | 22.69 | | **SciFact** | 76.26 | 77.78 | 79.94 | 80.98 | | **Touche2020** | 26.24 | 35.79 | 28.69 | 31.17 | | **TRECCOVID** | 87.07 | 88.13 | 86.61 | 87.36 | | **Mean** | 56.85 | 61.13 | 63.36 | **64.04** | - **MIRACL**: | MIRACL (dev, nDCG@10) | Average (18) | save flops | ar | bn | en | es | fa | fi | fr | hi | id | ja | ko | ru | sw | te | th | zh | de | yo | | :--------------------------------------: | :----------: | :--------: | :--: | :--: | :--: | :--: | :--: | :--: | :--: | :--: | :--: | :--: | :--: | :--: | :--: | :--: | :--: | :--: | :--: | :--: | | **bge-m3 (Dense)** | 69.2 | - | 78.4 | 80.0 | 56.9 | 56.1 | 60.9 | 78.6 | 58.3 | 59.5 | 56.1 | 72.8 | 69.9 | 70.1 | 78.7 | 86.2 | 82.6 | 62.7 | 56.7 | 81.8 | | **jina-reranker-v2-base-multilingual** | 69.6 | - | 73.4 | 81.9 | 58.9 | 58.6 | 60.5 | 77.2 | 56.1 | 62.7 | 59.6 | 72.7 | 74.0 | 67.1 | 78.1 | 85.8 | 81.2 | 63.0 | 58.2 | 84.2 | | **bge-reranker-v2-m3** | 74.4 | - | 81.7 | 84.6 | 63.5 | 64.4 | 65.7 | 82.4 | 63.7 | 68.5 | 62.7 | 80.0 | 73.8 | 76.9 | 82.3 | 89.4 | 85.3 | 65.2 | 62.7 | 87.4 | | **bge-reranker-v2-gemma** | 75.0 | - | 82.3 | 85.0 | 66.6 | 65.3 | 65.5 | 82.6 | 65.4 | 69.4 | 61.2 | 79.7 | 75.1 | 78.3 | 81.8 | 89.6 | 86.1 | 66.8 | 64.0 | 85.9 | | **bge-reranker-v2.5-gemma2-lightweight** | 77.1 | 60% | 82.5 | 87.8 | 68.6 | 67.6 | 67.5 | 82.8 | 68.5 | 71.4 | 63.8 | 82.8 | 75.9 | 79.8 | 84.8 | 90.8 | 88.1 | 69.9 | 65.8 | 89.6 | | **bge-reranker-v2.5-gemma-lightweight** | **77.3** | 0 | 82.8 | 87.6 | 69.3 | 67.8 | 67.4 | 83.3 | 68.5 | 71.3 | 63.8 | 83.6 | 75.7 | 80.1 | 85.1 | 90.8 | 88.7 | 69.9 | 65.6 | 89.8 | ## Citation If you find this repository useful, please consider giving a star and citation ```bibtex @misc{li2023making, title={Making Large Language Models A Better Foundation For Dense Retrieval}, author={Chaofan Li and Zheng Liu and Shitao Xiao and Yingxia Shao}, year={2023}, eprint={2312.15503}, archivePrefix={arXiv}, primaryClass={cs.CL} } @misc{chen2024bge, title={BGE M3-Embedding: Multi-Lingual, Multi-Functionality, Multi-Granularity Text Embeddings Through Self-Knowledge Distillation}, author={Jianlv Chen and Shitao Xiao and Peitian Zhang and Kun Luo and Defu Lian and Zheng Liu}, year={2024}, eprint={2402.03216}, archivePrefix={arXiv}, primaryClass={cs.CL} } ```