From 324666759032683e164e0dab8e1f52d57cb875bf Mon Sep 17 00:00:00 2001
From: Louis Dureuil <louis@meilisearch.com>
Date: Mon, 21 Jul 2025 15:09:31 +0200
Subject: [PATCH] when exporting vectors, for regenerate to false when the
 embedder has fragments

---
 .../src/scheduler/process_dump_creation.rs         | 14 ++++++++++++--
 .../src/scheduler/process_export.rs                | 14 ++++++++++++--
 crates/meilitool/src/main.rs                       | 14 ++++++++++++--
 3 files changed, 36 insertions(+), 6 deletions(-)

diff --git a/crates/index-scheduler/src/scheduler/process_dump_creation.rs b/crates/index-scheduler/src/scheduler/process_dump_creation.rs
index b8d100415..b14f23d0b 100644
--- a/crates/index-scheduler/src/scheduler/process_dump_creation.rs
+++ b/crates/index-scheduler/src/scheduler/process_dump_creation.rs
@@ -5,6 +5,7 @@ use std::sync::atomic::Ordering;
 
 use dump::IndexMetadata;
 use meilisearch_types::milli::constants::RESERVED_VECTORS_FIELD_NAME;
+use meilisearch_types::milli::index::EmbeddingsWithMetadata;
 use meilisearch_types::milli::progress::{Progress, VariableNameStep};
 use meilisearch_types::milli::vector::parsed_vectors::{ExplicitVectors, VectorOrArrayOfVectors};
 use meilisearch_types::milli::{self};
@@ -227,12 +228,21 @@ impl IndexScheduler {
                         return Err(Error::from_milli(user_err, Some(uid.to_string())));
                     };
 
-                    for (embedder_name, (embeddings, regenerate)) in embeddings {
+                    for (
+                        embedder_name,
+                        EmbeddingsWithMetadata { embeddings, regenerate, has_fragments },
+                    ) in embeddings
+                    {
                         let embeddings = ExplicitVectors {
                             embeddings: Some(VectorOrArrayOfVectors::from_array_of_vectors(
                                 embeddings,
                             )),
-                            regenerate,
+                            regenerate: regenerate &&
+                            // Meilisearch does not handle well dumps with fragments, because as the fragments
+                            // are marked as user-provided,
+                            // all embeddings would be regenerated on any settings change or document update.
+                            // To prevent this, we mark embeddings has non regenerate in this case.
+                            !has_fragments,
                         };
                         vectors.insert(embedder_name, serde_json::to_value(embeddings).unwrap());
                     }
diff --git a/crates/index-scheduler/src/scheduler/process_export.rs b/crates/index-scheduler/src/scheduler/process_export.rs
index a951a7ca6..0cd06f2e4 100644
--- a/crates/index-scheduler/src/scheduler/process_export.rs
+++ b/crates/index-scheduler/src/scheduler/process_export.rs
@@ -9,6 +9,7 @@ use flate2::write::GzEncoder;
 use flate2::Compression;
 use meilisearch_types::index_uid_pattern::IndexUidPattern;
 use meilisearch_types::milli::constants::RESERVED_VECTORS_FIELD_NAME;
+use meilisearch_types::milli::index::EmbeddingsWithMetadata;
 use meilisearch_types::milli::progress::{Progress, VariableNameStep};
 use meilisearch_types::milli::update::{request_threads, Setting};
 use meilisearch_types::milli::vector::parsed_vectors::{ExplicitVectors, VectorOrArrayOfVectors};
@@ -229,12 +230,21 @@ impl IndexScheduler {
                                 ));
                             };
 
-                            for (embedder_name, (embeddings, regenerate)) in embeddings {
+                            for (
+                                embedder_name,
+                                EmbeddingsWithMetadata { embeddings, regenerate, has_fragments },
+                            ) in embeddings
+                            {
                                 let embeddings = ExplicitVectors {
                                     embeddings: Some(
                                         VectorOrArrayOfVectors::from_array_of_vectors(embeddings),
                                     ),
-                                    regenerate,
+                                    regenerate: regenerate &&
+                                    // Meilisearch does not handle well dumps with fragments, because as the fragments
+                                    // are marked as user-provided,
+                                    // all embeddings would be regenerated on any settings change or document update.
+                                    // To prevent this, we mark embeddings has non regenerate in this case.
+                                    !has_fragments,
                                 };
                                 vectors.insert(
                                     embedder_name,
diff --git a/crates/meilitool/src/main.rs b/crates/meilitool/src/main.rs
index b967e620c..170bbdcc8 100644
--- a/crates/meilitool/src/main.rs
+++ b/crates/meilitool/src/main.rs
@@ -15,6 +15,7 @@ use meilisearch_types::heed::{
 };
 use meilisearch_types::milli::constants::RESERVED_VECTORS_FIELD_NAME;
 use meilisearch_types::milli::documents::{obkv_to_object, DocumentsBatchReader};
+use meilisearch_types::milli::index::EmbeddingsWithMetadata;
 use meilisearch_types::milli::vector::parsed_vectors::{ExplicitVectors, VectorOrArrayOfVectors};
 use meilisearch_types::milli::{obkv_to_json, BEU32};
 use meilisearch_types::tasks::{Status, Task};
@@ -591,12 +592,21 @@ fn export_documents(
                             .into());
                         };
 
-                        for (embedder_name, (embeddings, regenerate)) in embeddings {
+                        for (
+                            embedder_name,
+                            EmbeddingsWithMetadata { embeddings, regenerate, has_fragments },
+                        ) in embeddings
+                        {
                             let embeddings = ExplicitVectors {
                                 embeddings: Some(VectorOrArrayOfVectors::from_array_of_vectors(
                                     embeddings,
                                 )),
-                                regenerate,
+                                regenerate: regenerate &&
+                                // Meilisearch does not handle well dumps with fragments, because as the fragments
+                                // are marked as user-provided,
+                                // all embeddings would be regenerated on any settings change or document update.
+                                // To prevent this, we mark embeddings has non regenerate in this case.
+                                !has_fragments,
                             };
                             vectors
                                 .insert(embedder_name, serde_json::to_value(embeddings).unwrap());