Improve errors when indexing documents with a user provided embedder

meilisearch-types/src/error.rs

@@ -415,7 +415,9 @@ impl ErrorCode for milli::Error {
                         Code::InvalidSettingsTypoTolerance
                     }
                     UserError::InvalidEmbedder(_) => Code::InvalidEmbedder,
-                    UserError::VectorEmbeddingError(_) => Code::VectorEmbeddingError,
+                    UserError::VectorEmbeddingError(_) | UserError::DocumentEmbeddingError(_) => {
+                        Code::VectorEmbeddingError
+                    }
                     UserError::DocumentEditionCannotModifyPrimaryKey
                     | UserError::DocumentEditionDocumentMustBeObject
                     | UserError::DocumentEditionRuntimeError(_)

milli/src/error.rs

@@ -268,15 +268,17 @@ only composed of alphanumeric characters (a-z A-Z 0-9), hyphens (-) and undersco
     DocumentEditionRuntimeError(Box<EvalAltResult>),
     #[error("Document edition runtime error encountered while compiling the function: {0}")]
     DocumentEditionCompilationError(rhai::ParseError),
+    #[error("{0}")]
+    DocumentEmbeddingError(String),
 }
 
 impl From<crate::vector::Error> for Error {
     fn from(value: crate::vector::Error) -> Self {
         match value.fault() {
             FaultSource::User => Error::UserError(value.into()),
-            FaultSource::Runtime => Error::InternalError(value.into()),
+            FaultSource::Runtime => Error::UserError(value.into()),
             FaultSource::Bug => Error::InternalError(value.into()),
-            FaultSource::Undecided => Error::InternalError(value.into()),
+            FaultSource::Undecided => Error::UserError(value.into()),
         }
     }
 }

milli/src/update/index_documents/extract/extract_vector_points.rs

@@ -13,13 +13,15 @@ use roaring::RoaringBitmap;
 use serde_json::Value;
 
 use super::helpers::{create_writer, writer_into_reader, GrenadParameters};
+use crate::error::FaultSource;
 use crate::index::IndexEmbeddingConfig;
 use crate::prompt::Prompt;
 use crate::update::del_add::{DelAdd, KvReaderDelAdd, KvWriterDelAdd};
 use crate::update::settings::InnerIndexSettingsDiff;
+use crate::vector::error::{EmbedErrorKind, PossibleEmbeddingMistakes, UnusedVectorsDistribution};
 use crate::vector::parsed_vectors::{ParsedVectorsDiff, VectorState, RESERVED_VECTORS_FIELD_NAME};
 use crate::vector::settings::{EmbedderAction, ReindexAction};
-use crate::vector::Embedder;
+use crate::vector::{Embedder, Embeddings};
 use crate::{try_split_array_at, DocumentId, FieldId, FieldsIdsMap, Result, ThreadPoolNoAbort};
 
 /// The length of the elements that are always in the buffer when inserting new values.
@@ -102,7 +104,8 @@ pub fn extract_vector_points<R: io::Read + io::Seek>(
     indexer: GrenadParameters,
     embedders_configs: &[IndexEmbeddingConfig],
     settings_diff: &InnerIndexSettingsDiff,
-) -> Result<Vec<ExtractedVectorPoints>> {
+) -> Result<(Vec<ExtractedVectorPoints>, UnusedVectorsDistribution)> {
+    let mut unused_vectors_distribution = UnusedVectorsDistribution::new();
     let reindex_vectors = settings_diff.reindex_vectors();
 
     let old_fields_ids_map = &settings_diff.old.fields_ids_map;
@@ -319,6 +322,8 @@ pub fn extract_vector_points<R: io::Read + io::Seek>(
                 delta,
             )?;
         }
+
+        unused_vectors_distribution.append(parsed_vectors);
     }
 
     let mut results = Vec::new();
@@ -355,7 +360,7 @@ pub fn extract_vector_points<R: io::Read + io::Seek>(
         })
     }
 
-    Ok(results)
+    Ok((results, unused_vectors_distribution))
 }
 
 fn extract_vector_document_diff(
@@ -547,6 +552,9 @@ pub fn extract_embeddings<R: io::Read + io::Seek>(
     prompt_reader: grenad::Reader<R>,
     indexer: GrenadParameters,
     embedder: Arc<Embedder>,
+    embedder_name: &str,
+    possible_embedding_mistakes: &PossibleEmbeddingMistakes,
+    unused_vectors_distribution: &UnusedVectorsDistribution,
     request_threads: &ThreadPoolNoAbort,
 ) -> Result<grenad::Reader<BufReader<File>>> {
     let n_chunks = embedder.chunk_count_hint(); // chunk level parallelism
@@ -583,13 +591,14 @@ pub fn extract_embeddings<R: io::Read + io::Seek>(
         current_chunk_ids.push(docid);
 
         if chunks.len() == chunks.capacity() {
-            let chunked_embeds = embedder
-                .embed_chunks(
+            let chunked_embeds = embed_chunks(
+                &embedder,
                 std::mem::replace(&mut chunks, Vec::with_capacity(n_chunks)),
+                embedder_name,
+                possible_embedding_mistakes,
+                unused_vectors_distribution,
                 request_threads,
-                )
-                .map_err(crate::vector::Error::from)
-                .map_err(crate::Error::from)?;
+            )?;
 
             for (docid, embeddings) in chunks_ids
                 .iter()
@@ -604,10 +613,14 @@ pub fn extract_embeddings<R: io::Read + io::Seek>(
 
     // send last chunk
     if !chunks.is_empty() {
-        let chunked_embeds = embedder
-            .embed_chunks(std::mem::take(&mut chunks), request_threads)
-            .map_err(crate::vector::Error::from)
-            .map_err(crate::Error::from)?;
+        let chunked_embeds = embed_chunks(
+            &embedder,
+            std::mem::take(&mut chunks),
+            embedder_name,
+            possible_embedding_mistakes,
+            unused_vectors_distribution,
+            request_threads,
+        )?;
         for (docid, embeddings) in chunks_ids
             .iter()
             .flat_map(|docids| docids.iter())
@@ -618,10 +631,14 @@ pub fn extract_embeddings<R: io::Read + io::Seek>(
     }
 
     if !current_chunk.is_empty() {
-        let embeds = embedder
-            .embed_chunks(vec![std::mem::take(&mut current_chunk)], request_threads)
-            .map_err(crate::vector::Error::from)
-            .map_err(crate::Error::from)?;
+        let embeds = embed_chunks(
+            &embedder,
+            vec![std::mem::take(&mut current_chunk)],
+            embedder_name,
+            possible_embedding_mistakes,
+            unused_vectors_distribution,
+            request_threads,
+        )?;
 
         if let Some(embeds) = embeds.first() {
             for (docid, embeddings) in current_chunk_ids.iter().zip(embeds.iter()) {
@@ -632,3 +649,57 @@ pub fn extract_embeddings<R: io::Read + io::Seek>(
 
     writer_into_reader(state_writer)
 }
+
+fn embed_chunks(
+    embedder: &Embedder,
+    text_chunks: Vec<Vec<String>>,
+    embedder_name: &str,
+    possible_embedding_mistakes: &PossibleEmbeddingMistakes,
+    unused_vectors_distribution: &UnusedVectorsDistribution,
+    request_threads: &ThreadPoolNoAbort,
+) -> Result<Vec<Vec<Embeddings<f32>>>> {
+    match embedder.embed_chunks(text_chunks, request_threads) {
+        Ok(chunks) => Ok(chunks),
+        Err(error) => {
+            if let FaultSource::Bug = error.fault {
+                Err(crate::Error::InternalError(crate::InternalError::VectorEmbeddingError(
+                    error.into(),
+                )))
+            } else {
+                let mut msg =
+                    format!(r"While embedding documents for embedder `{embedder_name}`: {error}");
+
+                if let EmbedErrorKind::ManualEmbed(_) = &error.kind {
+                    msg += &format!("\n- Note: `{embedder_name}` has `source: userProvided`, so documents must provide embeddings as an array in `_vectors.{embedder_name}`.");
+                }
+
+                let mut hint_count = 0;
+
+                for (vector_misspelling, count) in
+                    possible_embedding_mistakes.vector_mistakes().take(2)
+                {
+                    msg += &format!("\n- Hint: try replacing `{vector_misspelling}` by `_vectors` in {count} document(s).");
+                    hint_count += 1;
+                }
+
+                for (embedder_misspelling, count) in possible_embedding_mistakes
+                    .embedder_mistakes(embedder_name, unused_vectors_distribution)
+                    .take(2)
+                {
+                    msg += &format!("\n- Hint: try replacing `_vectors.{embedder_misspelling}` by `_vectors.{embedder_name}` in {count} document(s).");
+                    hint_count += 1;
+                }
+
+                if hint_count == 0 {
+                    if let EmbedErrorKind::ManualEmbed(_) = &error.kind {
+                        msg += &format!(
+                            "\n- Hint: opt-out for a document with `_vectors.{embedder_name}: null`"
+                        );
+                    }
+                }
+
+                Err(crate::Error::UserError(crate::UserError::DocumentEmbeddingError(msg)))
+            }
+        }
+    }
+}

milli/src/update/index_documents/extract/mod.rs

@@ -32,6 +32,7 @@ use super::helpers::{as_cloneable_grenad, CursorClonableMmap, GrenadParameters};
 use super::{helpers, TypedChunk};
 use crate::index::IndexEmbeddingConfig;
 use crate::update::settings::InnerIndexSettingsDiff;
+use crate::vector::error::PossibleEmbeddingMistakes;
 use crate::{FieldId, Result, ThreadPoolNoAbort, ThreadPoolNoAbortBuilder};
 
 /// Extract data for each databases from obkv documents in parallel.
@@ -47,6 +48,7 @@ pub(crate) fn data_from_obkv_documents(
     embedders_configs: Arc<Vec<IndexEmbeddingConfig>>,
     settings_diff: Arc<InnerIndexSettingsDiff>,
     max_positions_per_attributes: Option<u32>,
+    possible_embedding_mistakes: Arc<PossibleEmbeddingMistakes>,
 ) -> Result<()> {
     let (original_pipeline_result, flattened_pipeline_result): (Result<_>, Result<_>) = rayon::join(
         || {
@@ -59,6 +61,7 @@ pub(crate) fn data_from_obkv_documents(
                         lmdb_writer_sx.clone(),
                         embedders_configs.clone(),
                         settings_diff.clone(),
+                        possible_embedding_mistakes.clone(),
                     )
                 })
                 .collect::<Result<()>>()
@@ -227,6 +230,7 @@ fn send_original_documents_data(
     lmdb_writer_sx: Sender<Result<TypedChunk>>,
     embedders_configs: Arc<Vec<IndexEmbeddingConfig>>,
     settings_diff: Arc<InnerIndexSettingsDiff>,
+    possible_embedding_mistakes: Arc<PossibleEmbeddingMistakes>,
 ) -> Result<()> {
     let original_documents_chunk =
         original_documents_chunk.and_then(|c| unsafe { as_cloneable_grenad(&c) })?;
@@ -248,7 +252,7 @@ fn send_original_documents_data(
                 &embedders_configs,
                 &settings_diff,
             ) {
-                Ok(extracted_vectors) => {
+                Ok((extracted_vectors, unused_vectors_distribution)) => {
                     for ExtractedVectorPoints {
                         manual_vectors,
                         remove_vectors,
@@ -263,6 +267,9 @@ fn send_original_documents_data(
                             prompts,
                             indexer,
                             embedder.clone(),
+                            &embedder_name,
+                            &possible_embedding_mistakes,
+                            &unused_vectors_distribution,
                             request_threads(),
                         ) {
                             Ok(results) => Some(results),

milli/src/update/index_documents/mod.rs

@@ -427,6 +427,9 @@ where
         let settings_diff = Arc::new(settings_diff);
         let embedders_configs = Arc::new(self.index.embedding_configs(self.wtxn)?);
 
+        let possible_embedding_mistakes =
+            crate::vector::error::PossibleEmbeddingMistakes::new(&field_distribution);
+
         let backup_pool;
         let pool = match self.indexer_config.thread_pool {
             Some(ref pool) => pool,
@@ -542,6 +545,7 @@ where
                         embedders_configs.clone(),
                         settings_diff_cloned,
                         max_positions_per_attributes,
+                        Arc::new(possible_embedding_mistakes)
                     )
                 });
 

milli/src/vector/error.rs

@@ -1,9 +1,11 @@
+use std::collections::BTreeMap;
 use std::path::PathBuf;
 
 use hf_hub::api::sync::ApiError;
 
+use super::parsed_vectors::ParsedVectorsDiff;
 use crate::error::FaultSource;
-use crate::PanicCatched;
+use crate::{FieldDistribution, PanicCatched};
 
 #[derive(Debug, thiserror::Error)]
 #[error("Error while generating embeddings: {inner}")]
@@ -310,3 +312,68 @@ pub enum NewEmbedderErrorKind {
     #[error("loading model failed: {0}")]
     LoadModel(candle_core::Error),
 }
+
+pub struct PossibleEmbeddingMistakes {
+    vectors_mistakes: BTreeMap<String, u64>,
+}
+
+impl PossibleEmbeddingMistakes {
+    pub fn new(field_distribution: &FieldDistribution) -> Self {
+        let mut vectors_mistakes = BTreeMap::new();
+        let builder = levenshtein_automata::LevenshteinAutomatonBuilder::new(2, true);
+        let automata = builder.build_dfa("_vectors");
+        for (field, count) in field_distribution {
+            if *count == 0 {
+                continue;
+            }
+            if field.contains('.') {
+                continue;
+            }
+            match automata.eval(field) {
+                levenshtein_automata::Distance::Exact(0) => continue,
+                levenshtein_automata::Distance::Exact(_) => {
+                    vectors_mistakes.insert(field.to_string(), *count);
+                }
+                levenshtein_automata::Distance::AtLeast(_) => continue,
+            }
+        }
+
+        Self { vectors_mistakes }
+    }
+
+    pub fn vector_mistakes(&self) -> impl Iterator<Item = (&str, u64)> {
+        self.vectors_mistakes.iter().map(|(misspelling, count)| (misspelling.as_str(), *count))
+    }
+
+    pub fn embedder_mistakes<'a>(
+        &'a self,
+        embedder_name: &'a str,
+        unused_vectors_distributions: &'a UnusedVectorsDistribution,
+    ) -> impl Iterator<Item = (&'a str, u64)> + 'a {
+        let builder = levenshtein_automata::LevenshteinAutomatonBuilder::new(2, true);
+        let automata = builder.build_dfa(embedder_name);
+
+        unused_vectors_distributions.0.iter().filter_map(move |(field, count)| {
+            match automata.eval(field) {
+                levenshtein_automata::Distance::Exact(0) => None,
+                levenshtein_automata::Distance::Exact(_) => Some((field.as_str(), *count)),
+                levenshtein_automata::Distance::AtLeast(_) => None,
+            }
+        })
+    }
+}
+
+#[derive(Default)]
+pub struct UnusedVectorsDistribution(BTreeMap<String, u64>);
+
+impl UnusedVectorsDistribution {
+    pub fn new() -> Self {
+        Self::default()
+    }
+
+    pub fn append(&mut self, parsed_vectors_diff: ParsedVectorsDiff) {
+        for name in parsed_vectors_diff.into_new_vectors_keys_iter() {
+            *self.0.entry(name).or_default() += 1;
+        }
+    }
+}

milli/src/vector/parsed_vectors.rs

@@ -179,6 +179,15 @@ impl ParsedVectorsDiff {
 
         (old, new)
     }
+
+    pub fn into_new_vectors_keys_iter(self) -> impl Iterator<Item = String> {
+        let maybe_it = match self.new {
+            VectorsState::NoVectorsFid => None,
+            VectorsState::NoVectorsFieldInDocument => None,
+            VectorsState::Vectors(vectors) => Some(vectors.into_keys()),
+        };
+        maybe_it.into_iter().flatten()
+    }
 }
 
 pub struct ParsedVectors(pub BTreeMap<String, Vectors>);