We were attempting to load SentenceTransformers by looking at the model prefix, however SentenceTransformers can also be loaded from other orgs in the model hub, as well as from local disk. This prefix checking failed in those two cases. To simplify the loading logic and deciding which wrapper to use, we’ve removed support for text_embedding tasks to load a plain Transformer. We now only support DPR embedding models and SentenceTransformer embedding models. If you try to load a plain Transformer model, it will be loaded by SentenceTransformers and a mean pooling layer will automatically be added by the SentenceTransformer library. Since we no longer automatically support non-DPR and non-SentenceTransformers, we should include somewhere example code for how to load a custom model without DPR or SentenceTransformers.
Note: This change will allow us to support E5 embeddings uploaded with eland. This change will not yet solve adding the preamble instructions to query and index embeddings.
joshdevins
commented
1 year ago
We were attempting to load SentenceTransformers by looking at the model prefix, however SentenceTransformers can also be loaded from other orgs in the model hub, as well as from local disk. This prefix checking failed in those two cases. To simplify the loading logic and deciding which wrapper to use, we’ve removed support for text_embedding tasks to load a plain Transformer. We now only support DPR embedding models and SentenceTransformer embedding models. If you try to load a plain Transformer model, it will be loaded by SentenceTransformers and a mean pooling layer will automatically be added by the SentenceTransformer library. Since we no longer automatically support non-DPR and non-SentenceTransformers, we should include somewhere example code for how to load a custom model without DPR or SentenceTransformers.
Note: This change will allow us to support E5 embeddings uploaded with eland. This change will not yet solve adding the preamble instructions to query and index embeddings.
See: https://github.com/UKPLab/sentence-transformers/blob/v2.2.2/sentence_transformers/SentenceTransformer.py#L801
Resolves #531