Remove a log that would log too much

5276: Fix the stuck indexation due to the internal BBQueue capacity r=curquiza a=Kerollmops

Fixes https://github.com/meilisearch/meilisearch/issues/5277. Reduce the maximum reserve grant in the BBQueue so we are never stuck.

Co-authored-by: Kerollmops <clement@meilisearch.com>
Co-authored-by: Louis Dureuil <louis@meilisearch.com>
Co-authored-by: Clément Renault <clement@meilisearch.com>

Cargo.lock

@@ -496,7 +496,7 @@ source = "git+https://github.com/meilisearch/bbqueue#cbb87cc707b5af415ef203bdaf2
 
 [[package]]
 name = "benchmarks"
-version = "1.12.2"
+version = "1.12.7"
 dependencies = [
  "anyhow",
  "bumpalo",
@@ -689,7 +689,7 @@ dependencies = [
 
 [[package]]
 name = "build-info"
-version = "1.12.2"
+version = "1.12.7"
 dependencies = [
  "anyhow",
  "time",
@@ -1664,7 +1664,7 @@ dependencies = [
 
 [[package]]
 name = "dump"
-version = "1.12.2"
+version = "1.12.7"
 dependencies = [
  "anyhow",
  "big_s",
@@ -1876,7 +1876,7 @@ checksum = "486f806e73c5707928240ddc295403b1b93c96a02038563881c4a2fd84b81ac4"
 
 [[package]]
 name = "file-store"
-version = "1.12.2"
+version = "1.12.7"
 dependencies = [
  "tempfile",
  "thiserror",
@@ -1898,7 +1898,7 @@ dependencies = [
 
 [[package]]
 name = "filter-parser"
-version = "1.12.2"
+version = "1.12.7"
 dependencies = [
  "insta",
  "nom",
@@ -1918,7 +1918,7 @@ dependencies = [
 
 [[package]]
 name = "flatten-serde-json"
-version = "1.12.2"
+version = "1.12.7"
 dependencies = [
  "criterion",
  "serde_json",
@@ -2057,7 +2057,7 @@ dependencies = [
 
 [[package]]
 name = "fuzzers"
-version = "1.12.2"
+version = "1.12.7"
 dependencies = [
  "arbitrary",
  "bumpalo",
@@ -2624,7 +2624,7 @@ checksum = "206ca75c9c03ba3d4ace2460e57b189f39f43de612c2f85836e65c929701bb2d"
 
 [[package]]
 name = "index-scheduler"
-version = "1.12.2"
+version = "1.12.7"
 dependencies = [
  "anyhow",
  "arroy 0.5.0 (registry+https://github.com/rust-lang/crates.io-index)",
@@ -2822,7 +2822,7 @@ dependencies = [
 
 [[package]]
 name = "json-depth-checker"
-version = "1.12.2"
+version = "1.12.7"
 dependencies = [
  "criterion",
  "serde_json",
@@ -3441,7 +3441,7 @@ checksum = "490cc448043f947bae3cbee9c203358d62dbee0db12107a74be5c30ccfd09771"
 
 [[package]]
 name = "meili-snap"
-version = "1.12.2"
+version = "1.12.7"
 dependencies = [
  "insta",
  "md5",
@@ -3450,7 +3450,7 @@ dependencies = [
 
 [[package]]
 name = "meilisearch"
-version = "1.12.2"
+version = "1.12.7"
 dependencies = [
  "actix-cors",
  "actix-http",
@@ -3540,7 +3540,7 @@ dependencies = [
 
 [[package]]
 name = "meilisearch-auth"
-version = "1.12.2"
+version = "1.12.7"
 dependencies = [
  "base64 0.22.1",
  "enum-iterator",
@@ -3559,7 +3559,7 @@ dependencies = [
 
 [[package]]
 name = "meilisearch-types"
-version = "1.12.2"
+version = "1.12.7"
 dependencies = [
  "actix-web",
  "anyhow",
@@ -3592,7 +3592,7 @@ dependencies = [
 
 [[package]]
 name = "meilitool"
-version = "1.12.2"
+version = "1.12.7"
 dependencies = [
  "anyhow",
  "arroy 0.5.0 (git+https://github.com/meilisearch/arroy/?tag=DO-NOT-DELETE-upgrade-v04-to-v05)",
@@ -3627,7 +3627,7 @@ dependencies = [
 
 [[package]]
 name = "milli"
-version = "1.12.2"
+version = "1.12.7"
 dependencies = [
  "allocator-api2",
  "arroy 0.5.0 (registry+https://github.com/rust-lang/crates.io-index)",
@@ -4083,7 +4083,7 @@ checksum = "e3148f5046208a5d56bcfc03053e3ca6334e51da8dfb19b6cdc8b306fae3283e"
 
 [[package]]
 name = "permissive-json-pointer"
-version = "1.12.2"
+version = "1.12.7"
 dependencies = [
  "big_s",
  "serde_json",
@@ -6486,7 +6486,7 @@ dependencies = [
 
 [[package]]
 name = "xtask"
-version = "1.12.2"
+version = "1.12.7"
 dependencies = [
  "anyhow",
  "build-info",

Cargo.toml

@@ -22,7 +22,7 @@ members = [
 ]
 
 [workspace.package]
-version = "1.12.2"
+version = "1.12.7"
 authors = [
     "Quentin de Quelen <quentin@dequelen.me>",
     "Clément Renault <clement@meilisearch.com>",

crates/index-scheduler/src/batch.rs

@@ -29,7 +29,7 @@ use bumpalo::Bump;
 use dump::IndexMetadata;
 use meilisearch_types::batches::BatchId;
 use meilisearch_types::heed::{RoTxn, RwTxn};
-use meilisearch_types::milli::documents::{obkv_to_object, DocumentsBatchReader, PrimaryKey};
+use meilisearch_types::milli::documents::PrimaryKey;
 use meilisearch_types::milli::heed::CompactionOption;
 use meilisearch_types::milli::progress::Progress;
 use meilisearch_types::milli::update::new::indexer::{self, UpdateByFunction};
@@ -819,6 +819,13 @@ impl IndexScheduler {
                         t.started_at = Some(started_at);
                         t.finished_at = Some(finished_at);
                     }
+
+                    // Patch the task to remove the batch uid, because as of v1.12.5 batches are not persisted.
+                    // This prevent from referencing *future* batches not actually associated with the task.
+                    //
+                    // See <https://github.com/meilisearch/meilisearch/issues/5247> for details.
+                    t.batch_uid = None;
+
                     let mut dump_content_file = dump_tasks.push_task(&t.into())?;
 
                     // 2.1. Dump the `content_file` associated with the task if there is one and the task is not finished yet.
@@ -829,21 +836,18 @@ impl IndexScheduler {
                         if status == Status::Enqueued {
                             let content_file = self.file_store.get_update(content_file)?;
 
-                            let reader = DocumentsBatchReader::from_reader(content_file)
-                                .map_err(|e| Error::from_milli(e.into(), None))?;
-
-                            let (mut cursor, documents_batch_index) =
-                                reader.into_cursor_and_fields_index();
-
-                            while let Some(doc) = cursor
-                                .next_document()
-                                .map_err(|e| Error::from_milli(e.into(), None))?
+                            for document in
+                                serde_json::de::Deserializer::from_reader(content_file).into_iter()
                             {
-                                dump_content_file.push_document(
-                                    &obkv_to_object(doc, &documents_batch_index)
-                                        .map_err(|e| Error::from_milli(e, None))?,
-                                )?;
+                                let document = document.map_err(|e| {
+                                    Error::from_milli(
+                                        milli::InternalError::SerdeJson(e).into(),
+                                        None,
+                                    )
+                                })?;
+                                dump_content_file.push_document(&document)?;
                             }
+
                             dump_content_file.flush()?;
                         }
                     }

crates/index-scheduler/src/index_mapper/index_map.rs

@@ -1,5 +1,7 @@
 use std::collections::BTreeMap;
+use std::env::VarError;
 use std::path::Path;
+use std::str::FromStr;
 use std::time::Duration;
 
 use meilisearch_types::heed::{EnvClosingEvent, EnvFlags, EnvOpenOptions};
@@ -302,7 +304,15 @@ fn create_or_open_index(
 ) -> Result<Index> {
     let mut options = EnvOpenOptions::new();
     options.map_size(clamp_to_page_size(map_size));
-    options.max_readers(1024);
+
+    let max_readers = match std::env::var("MEILI_EXPERIMENTAL_INDEX_MAX_READERS") {
+        Ok(value) => u32::from_str(&value).unwrap(),
+        Err(VarError::NotPresent) => 1024,
+        Err(VarError::NotUnicode(value)) => panic!(
+            "Invalid unicode for the `MEILI_EXPERIMENTAL_INDEX_MAX_READERS` env var: {value:?}"
+        ),
+    };
+    options.max_readers(max_readers);
     if enable_mdb_writemap {
         unsafe { options.flags(EnvFlags::WRITE_MAP) };
     }

crates/index-scheduler/src/lib.rs

@@ -55,7 +55,6 @@ use meilisearch_types::features::{InstanceTogglableFeatures, RuntimeTogglableFea
 use meilisearch_types::heed::byteorder::BE;
 use meilisearch_types::heed::types::{SerdeBincode, SerdeJson, Str, I128};
 use meilisearch_types::heed::{self, Database, Env, PutFlags, RoTxn, RwTxn};
-use meilisearch_types::milli::documents::DocumentsBatchBuilder;
 use meilisearch_types::milli::index::IndexEmbeddingConfig;
 use meilisearch_types::milli::update::IndexerConfig;
 use meilisearch_types::milli::vector::{Embedder, EmbedderOptions, EmbeddingConfigs};
@@ -2017,14 +2016,19 @@ impl<'a> Dump<'a> {
         task: TaskDump,
         content_file: Option<Box<UpdateFile>>,
     ) -> Result<Task> {
+        let task_has_no_docs = matches!(task.kind, KindDump::DocumentImport { documents_count, .. } if documents_count == 0);
+
         let content_uuid = match content_file {
             Some(content_file) if task.status == Status::Enqueued => {
-                let (uuid, mut file) = self.index_scheduler.create_update_file(false)?;
-                let mut builder = DocumentsBatchBuilder::new(&mut file);
+                let (uuid, file) = self.index_scheduler.create_update_file(false)?;
+                let mut writer = io::BufWriter::new(file);
                 for doc in content_file {
-                    builder.append_json_object(&doc?)?;
+                    let doc = doc?;
+                    serde_json::to_writer(&mut writer, &doc).map_err(|e| {
+                        Error::from_milli(milli::InternalError::SerdeJson(e).into(), None)
+                    })?;
                 }
-                builder.into_inner()?;
+                let file = writer.into_inner().map_err(|e| e.into_error())?;
                 file.persist()?;
 
                 Some(uuid)
@@ -2032,6 +2036,12 @@ impl<'a> Dump<'a> {
             // If the task isn't `Enqueued` then just generate a recognisable `Uuid`
             // in case we try to open it later.
             _ if task.status != Status::Enqueued => Some(Uuid::nil()),
+            None if task.status == Status::Enqueued && task_has_no_docs => {
+                let (uuid, file) = self.index_scheduler.create_update_file(false)?;
+                file.persist()?;
+
+                Some(uuid)
+            }
             _ => None,
         };
 

crates/meilisearch/tests/search/mod.rs

@@ -1746,3 +1746,57 @@ async fn change_attributes_settings() {
         )
         .await;
 }
+
+/// Modifying facets with different casing should work correctly
+#[actix_rt::test]
+async fn change_facet_casing() {
+    let server = Server::new().await;
+    let index = server.index("test");
+
+    let (response, code) = index
+        .update_settings(json!({
+            "filterableAttributes": ["dog"],
+        }))
+        .await;
+    assert_eq!("202", code.as_str(), "{:?}", response);
+    index.wait_task(response.uid()).await;
+
+    let (response, _code) = index
+        .add_documents(
+            json!([
+                {
+                    "id": 1,
+                    "dog": "Bouvier Bernois"
+                }
+            ]),
+            None,
+        )
+        .await;
+    index.wait_task(response.uid()).await;
+
+    let (response, _code) = index
+        .add_documents(
+            json!([
+                {
+                    "id": 1,
+                    "dog": "bouvier bernois"
+                }
+            ]),
+            None,
+        )
+        .await;
+    index.wait_task(response.uid()).await;
+
+    index
+        .search(json!({ "facets": ["dog"] }), |response, code| {
+            meili_snap::snapshot!(code, @"200 OK");
+            meili_snap::snapshot!(meili_snap::json_string!(response["facetDistribution"]), @r###"
+            {
+              "dog": {
+                "bouvier bernois": 1
+              }
+            }
+            "###);
+        })
+        .await;
+}

crates/meilitool/Cargo.toml

@@ -14,11 +14,11 @@ arroy_v04_to_v05 = { package = "arroy", git = "https://github.com/meilisearch/ar
 clap = { version = "4.5.9", features = ["derive"] }
 dump = { path = "../dump" }
 file-store = { path = "../file-store" }
-indexmap = {version = "2.7.0", features = ["serde"]}
+indexmap = { version = "2.7.0", features = ["serde"] }
 meilisearch-auth = { path = "../meilisearch-auth" }
 meilisearch-types = { path = "../meilisearch-types" }
 serde = { version = "1.0.209", features = ["derive"] }
-serde_json = {version = "1.0.133", features = ["preserve_order"]}
+serde_json = { version = "1.0.133", features = ["preserve_order"] }
 tempfile = "3.14.0"
 time = { version = "0.3.36", features = ["formatting", "parsing", "alloc"] }
 uuid = { version = "1.10.0", features = ["v4"], default-features = false }

crates/meilitool/src/main.rs

@@ -88,7 +88,7 @@ fn main() -> anyhow::Result<()> {
     match command {
         Command::ClearTaskQueue => clear_task_queue(db_path),
         Command::ExportADump { dump_dir, skip_enqueued_tasks } => {
-            export_a_dump(db_path, dump_dir, skip_enqueued_tasks)
+            export_a_dump(db_path, dump_dir, skip_enqueued_tasks, detected_version)
         }
         Command::OfflineUpgrade { target_version } => {
             let target_version = parse_version(&target_version).context("While parsing `--target-version`. Make sure `--target-version` is in the format MAJOR.MINOR.PATCH")?;
@@ -187,6 +187,7 @@ fn export_a_dump(
     db_path: PathBuf,
     dump_dir: PathBuf,
     skip_enqueued_tasks: bool,
+    detected_version: (String, String, String),
 ) -> Result<(), anyhow::Error> {
     let started_at = OffsetDateTime::now_utc();
 
@@ -238,9 +239,6 @@ fn export_a_dump(
     if skip_enqueued_tasks {
         eprintln!("Skip dumping the enqueued tasks...");
     } else {
-        eprintln!("Dumping the enqueued tasks...");
-
-        // 3. dump the tasks
         let mut dump_tasks = dump.create_tasks_queue()?;
         let mut count = 0;
         for ret in all_tasks.iter(&rtxn)? {
@@ -254,18 +252,39 @@ fn export_a_dump(
                 if status == Status::Enqueued {
                     let content_file = file_store.get_update(content_file_uuid)?;
 
-                    let reader =
-                        DocumentsBatchReader::from_reader(content_file).with_context(|| {
-                            format!("While reading content file {:?}", content_file_uuid)
-                        })?;
-
-                    let (mut cursor, documents_batch_index) = reader.into_cursor_and_fields_index();
-                    while let Some(doc) = cursor.next_document().with_context(|| {
-                        format!("While iterating on content file {:?}", content_file_uuid)
-                    })? {
-                        dump_content_file
-                            .push_document(&obkv_to_object(doc, &documents_batch_index)?)?;
+                    if (
+                        detected_version.0.as_str(),
+                        detected_version.1.as_str(),
+                        detected_version.2.as_str(),
+                    ) < ("1", "12", "0")
+                    {
+                        eprintln!("Dumping the enqueued tasks reading them in obkv format...");
+                        let reader =
+                            DocumentsBatchReader::from_reader(content_file).with_context(|| {
+                                format!("While reading content file {:?}", content_file_uuid)
+                            })?;
+                        let (mut cursor, documents_batch_index) =
+                            reader.into_cursor_and_fields_index();
+                        while let Some(doc) = cursor.next_document().with_context(|| {
+                            format!("While iterating on content file {:?}", content_file_uuid)
+                        })? {
+                            dump_content_file
+                                .push_document(&obkv_to_object(doc, &documents_batch_index)?)?;
+                        }
+                    } else {
+                        eprintln!(
+                            "Dumping the enqueued tasks reading them in JSON stream format..."
+                        );
+                        for document in
+                            serde_json::de::Deserializer::from_reader(content_file).into_iter()
+                        {
+                            let document = document.with_context(|| {
+                                format!("While reading content file {:?}", content_file_uuid)
+                            })?;
+                            dump_content_file.push_document(&document)?;
+                        }
                     }
+
                     dump_content_file.flush()?;
                     count += 1;
                 }

crates/meilitool/src/upgrade/mod.rs

@@ -8,7 +8,7 @@ use std::path::{Path, PathBuf};
 use anyhow::{bail, Context};
 use meilisearch_types::versioning::create_version_file;
 use v1_10::v1_9_to_v1_10;
-use v1_12::v1_11_to_v1_12;
+use v1_12::{v1_11_to_v1_12, v1_12_to_v1_12_3};
 
 use crate::upgrade::v1_11::v1_10_to_v1_11;
 
@@ -20,12 +20,48 @@ pub struct OfflineUpgrade {
 
 impl OfflineUpgrade {
     pub fn upgrade(self) -> anyhow::Result<()> {
+        // Adding a version?
+        //
+        // 1. Update the LAST_SUPPORTED_UPGRADE_FROM_VERSION and LAST_SUPPORTED_UPGRADE_TO_VERSION.
+        // 2. Add new version to the upgrade list if necessary
+        // 3. Use `no_upgrade` as index for versions that are compatible.
+
+        if self.current_version == self.target_version {
+            println!("Database is already at the target version. Exiting.");
+            return Ok(());
+        }
+
+        if self.current_version > self.target_version {
+            bail!(
+                "Cannot downgrade from {}.{}.{} to {}.{}.{}. Downgrade not supported",
+                self.current_version.0,
+                self.current_version.1,
+                self.current_version.2,
+                self.target_version.0,
+                self.target_version.1,
+                self.target_version.2
+            );
+        }
+
+        const FIRST_SUPPORTED_UPGRADE_FROM_VERSION: &str = "1.9.0";
+        const LAST_SUPPORTED_UPGRADE_FROM_VERSION: &str = "1.12.7";
+        const FIRST_SUPPORTED_UPGRADE_TO_VERSION: &str = "1.10.0";
+        const LAST_SUPPORTED_UPGRADE_TO_VERSION: &str = "1.12.7";
+
         let upgrade_list = [
-            (v1_9_to_v1_10 as fn(&Path) -> Result<(), anyhow::Error>, "1", "10", "0"),
+            (
+                v1_9_to_v1_10 as fn(&Path, &str, &str, &str) -> Result<(), anyhow::Error>,
+                "1",
+                "10",
+                "0",
+            ),
             (v1_10_to_v1_11, "1", "11", "0"),
             (v1_11_to_v1_12, "1", "12", "0"),
+            (v1_12_to_v1_12_3, "1", "12", "3"),
         ];
 
+        let no_upgrade: usize = upgrade_list.len();
+
         let (current_major, current_minor, current_patch) = &self.current_version;
 
         let start_at = match (
@@ -36,8 +72,12 @@ impl OfflineUpgrade {
             ("1", "9", _) => 0,
             ("1", "10", _) => 1,
             ("1", "11", _) => 2,
+            ("1", "12", "0" | "1" | "2") => 3,
+            ("1", "12", "3" | "4" | "5" | "6" | "7") => no_upgrade,
             _ => {
-                bail!("Unsupported current version {current_major}.{current_minor}.{current_patch}. Can only upgrade from v1.9 and v1.10")
+                bail!("Unsupported current version {current_major}.{current_minor}.{current_patch}. Can only upgrade from versions in range [{}-{}]",
+                      FIRST_SUPPORTED_UPGRADE_FROM_VERSION,
+                      LAST_SUPPORTED_UPGRADE_FROM_VERSION);
             }
         };
 
@@ -46,21 +86,32 @@ impl OfflineUpgrade {
         let ends_at = match (target_major.as_str(), target_minor.as_str(), target_patch.as_str()) {
             ("1", "10", _) => 0,
             ("1", "11", _) => 1,
-            ("1", "12", _) => 2,
+            ("1", "12", "0" | "1" | "2") => 2,
+            ("1", "12", "3" | "4" | "5" | "6" | "7") => 3,
             (major, _, _) if major.starts_with('v') => {
                 bail!("Target version must not starts with a `v`. Instead of writing `v1.9.0` write `1.9.0` for example.")
             }
             _ => {
-                bail!("Unsupported target version {target_major}.{target_minor}.{target_patch}. Can only upgrade to v1.10 and v1.11")
+                bail!("Unsupported target version {target_major}.{target_minor}.{target_patch}. Can only upgrade to versions in range [{}-{}]",
+                      FIRST_SUPPORTED_UPGRADE_TO_VERSION,
+                      LAST_SUPPORTED_UPGRADE_TO_VERSION);
             }
         };
 
         println!("Starting the upgrade from {current_major}.{current_minor}.{current_patch} to {target_major}.{target_minor}.{target_patch}");
 
+        if start_at == no_upgrade {
+            println!("No upgrade operation to perform, writing VERSION file");
+            create_version_file(&self.db_path, target_major, target_minor, target_patch)
+                .context("while writing VERSION file after the upgrade")?;
+            println!("Success");
+            return Ok(());
+        }
+
         #[allow(clippy::needless_range_loop)]
         for index in start_at..=ends_at {
             let (func, major, minor, patch) = upgrade_list[index];
-            (func)(&self.db_path)?;
+            (func)(&self.db_path, current_major, current_minor, current_patch)?;
             println!("Done");
             // We're writing the version file just in case an issue arise _while_ upgrading.
             // We don't want the DB to fail in an unknown state.

crates/meilitool/src/upgrade/v1_10.rs

@@ -151,7 +151,12 @@ fn date_round_trip(
     Ok(())
 }
 
-pub fn v1_9_to_v1_10(db_path: &Path) -> anyhow::Result<()> {
+pub fn v1_9_to_v1_10(
+    db_path: &Path,
+    _origin_major: &str,
+    _origin_minor: &str,
+    _origin_patch: &str,
+) -> anyhow::Result<()> {
     println!("Upgrading from v1.9.0 to v1.10.0");
     // 2 changes here
 

crates/meilitool/src/upgrade/v1_11.rs

@@ -14,7 +14,12 @@ use meilisearch_types::milli::index::db_name;
 use crate::uuid_codec::UuidCodec;
 use crate::{try_opening_database, try_opening_poly_database};
 
-pub fn v1_10_to_v1_11(db_path: &Path) -> anyhow::Result<()> {
+pub fn v1_10_to_v1_11(
+    db_path: &Path,
+    _origin_major: &str,
+    _origin_minor: &str,
+    _origin_patch: &str,
+) -> anyhow::Result<()> {
     println!("Upgrading from v1.10.0 to v1.11.0");
 
     let index_scheduler_path = db_path.join("tasks");

crates/meilitool/src/upgrade/v1_12.rs

@@ -1,17 +1,34 @@
 //! The breaking changes that happened between the v1.11 and the v1.12 are:
 //! - The new indexer changed the update files format from OBKV to ndjson. https://github.com/meilisearch/meilisearch/pull/4900
 
+use std::borrow::Cow;
 use std::io::BufWriter;
 use std::path::Path;
+use std::sync::atomic::AtomicBool;
 
 use anyhow::Context;
 use file_store::FileStore;
 use indexmap::IndexMap;
 use meilisearch_types::milli::documents::DocumentsBatchReader;
+use meilisearch_types::milli::heed::types::{SerdeJson, Str};
+use meilisearch_types::milli::heed::{Database, EnvOpenOptions, RoTxn, RwTxn};
+use meilisearch_types::milli::progress::Step;
+use meilisearch_types::milli::{FieldDistribution, Index};
+use serde::Serialize;
 use serde_json::value::RawValue;
 use tempfile::NamedTempFile;
+use time::OffsetDateTime;
+use uuid::Uuid;
 
-pub fn v1_11_to_v1_12(db_path: &Path) -> anyhow::Result<()> {
+use crate::try_opening_database;
+use crate::uuid_codec::UuidCodec;
+
+pub fn v1_11_to_v1_12(
+    db_path: &Path,
+    _origin_major: &str,
+    _origin_minor: &str,
+    _origin_patch: &str,
+) -> anyhow::Result<()> {
     println!("Upgrading from v1.11.0 to v1.12.0");
 
     convert_update_files(db_path)?;
@@ -19,6 +36,23 @@ pub fn v1_11_to_v1_12(db_path: &Path) -> anyhow::Result<()> {
     Ok(())
 }
 
+pub fn v1_12_to_v1_12_3(
+    db_path: &Path,
+    origin_major: &str,
+    origin_minor: &str,
+    origin_patch: &str,
+) -> anyhow::Result<()> {
+    println!("Upgrading from v1.12.{{0, 1, 2}} to v1.12.3");
+
+    if origin_minor == "12" {
+        rebuild_field_distribution(db_path)?;
+    } else {
+        println!("Not rebuilding field distribution as it wasn't corrupted coming from v{origin_major}.{origin_minor}.{origin_patch}");
+    }
+
+    Ok(())
+}
+
 /// Convert the update files from OBKV to ndjson format.
 ///
 /// 1) List all the update files using the file store.
@@ -77,3 +111,188 @@ fn convert_update_files(db_path: &Path) -> anyhow::Result<()> {
 
     Ok(())
 }
+
+/// Rebuild field distribution as it was wrongly computed in v1.12.x if x < 3
+fn rebuild_field_distribution(db_path: &Path) -> anyhow::Result<()> {
+    let index_scheduler_path = db_path.join("tasks");
+    let env = unsafe { EnvOpenOptions::new().max_dbs(100).open(&index_scheduler_path) }
+        .with_context(|| format!("While trying to open {:?}", index_scheduler_path.display()))?;
+
+    let mut sched_wtxn = env.write_txn()?;
+
+    let index_mapping: Database<Str, UuidCodec> =
+        try_opening_database(&env, &sched_wtxn, "index-mapping")?;
+    let stats_db: Database<UuidCodec, SerdeJson<IndexStats>> =
+        try_opening_database(&env, &sched_wtxn, "index-stats").with_context(|| {
+            format!("While trying to open {:?}", index_scheduler_path.display())
+        })?;
+
+    let index_count =
+        index_mapping.len(&sched_wtxn).context("while reading the number of indexes")?;
+
+    // FIXME: not ideal, we have to pre-populate all indexes to prevent double borrow of sched_wtxn
+    // 1. immutably for the iteration
+    // 2. mutably for updating index stats
+    let indexes: Vec<_> = index_mapping
+        .iter(&sched_wtxn)?
+        .map(|res| res.map(|(uid, uuid)| (uid.to_owned(), uuid)))
+        .collect();
+
+    let progress = meilisearch_types::milli::progress::Progress::default();
+    let finished = AtomicBool::new(false);
+
+    std::thread::scope(|scope| {
+        let display_progress = std::thread::Builder::new()
+            .name("display_progress".into())
+            .spawn_scoped(scope, || {
+                while !finished.load(std::sync::atomic::Ordering::Relaxed) {
+                    std::thread::sleep(std::time::Duration::from_secs(5));
+                    let view = progress.as_progress_view();
+                    let Ok(view) = serde_json::to_string(&view) else {
+                        continue;
+                    };
+                    println!("{view}");
+                }
+            })
+            .unwrap();
+
+        for (index_index, result) in indexes.into_iter().enumerate() {
+            let (uid, uuid) = result?;
+            progress.update_progress(VariableNameStep::new(
+                &uid,
+                index_index as u32,
+                index_count as u32,
+            ));
+            let index_path = db_path.join("indexes").join(uuid.to_string());
+
+            println!(
+                "[{}/{index_count}]Updating index `{uid}` at `{}`",
+                index_index + 1,
+                index_path.display()
+            );
+
+            println!("\t- Rebuilding field distribution");
+
+            let index = meilisearch_types::milli::Index::new(EnvOpenOptions::new(), &index_path)
+                .with_context(|| {
+                    format!("while opening index {uid} at '{}'", index_path.display())
+                })?;
+
+            let mut index_txn = index.write_txn()?;
+
+            meilisearch_types::milli::update::new::reindex::field_distribution(
+                &index,
+                &mut index_txn,
+                &progress,
+            )
+            .context("while rebuilding field distribution")?;
+
+            let stats = IndexStats::new(&index, &index_txn)
+                .with_context(|| format!("computing stats for index `{uid}`"))?;
+            store_stats_of(stats_db, uuid, &mut sched_wtxn, &uid, &stats)?;
+
+            index_txn.commit().context("while committing the write txn for the updated index")?;
+        }
+
+        sched_wtxn.commit().context("while committing the write txn for the index-scheduler")?;
+
+        finished.store(true, std::sync::atomic::Ordering::Relaxed);
+
+        if let Err(panic) = display_progress.join() {
+            let msg = match panic.downcast_ref::<&'static str>() {
+                Some(s) => *s,
+                None => match panic.downcast_ref::<String>() {
+                    Some(s) => &s[..],
+                    None => "Box<dyn Any>",
+                },
+            };
+            eprintln!("WARN: the display thread panicked with {msg}");
+        }
+
+        println!("Upgrading database succeeded");
+        Ok(())
+    })
+}
+
+pub struct VariableNameStep {
+    name: String,
+    current: u32,
+    total: u32,
+}
+
+impl VariableNameStep {
+    pub fn new(name: impl Into<String>, current: u32, total: u32) -> Self {
+        Self { name: name.into(), current, total }
+    }
+}
+
+impl Step for VariableNameStep {
+    fn name(&self) -> Cow<'static, str> {
+        self.name.clone().into()
+    }
+
+    fn current(&self) -> u32 {
+        self.current
+    }
+
+    fn total(&self) -> u32 {
+        self.total
+    }
+}
+
+pub fn store_stats_of(
+    stats_db: Database<UuidCodec, SerdeJson<IndexStats>>,
+    index_uuid: Uuid,
+    sched_wtxn: &mut RwTxn,
+    index_uid: &str,
+    stats: &IndexStats,
+) -> anyhow::Result<()> {
+    stats_db
+        .put(sched_wtxn, &index_uuid, stats)
+        .with_context(|| format!("storing stats for index `{index_uid}`"))?;
+    Ok(())
+}
+
+/// The statistics that can be computed from an `Index` object.
+#[derive(Serialize, Debug)]
+pub struct IndexStats {
+    /// Number of documents in the index.
+    pub number_of_documents: u64,
+    /// Size taken up by the index' DB, in bytes.
+    ///
+    /// This includes the size taken by both the used and free pages of the DB, and as the free pages
+    /// are not returned to the disk after a deletion, this number is typically larger than
+    /// `used_database_size` that only includes the size of the used pages.
+    pub database_size: u64,
+    /// Size taken by the used pages of the index' DB, in bytes.
+    ///
+    /// As the DB backend does not return to the disk the pages that are not currently used by the DB,
+    /// this value is typically smaller than `database_size`.
+    pub used_database_size: u64,
+    /// Association of every field name with the number of times it occurs in the documents.
+    pub field_distribution: FieldDistribution,
+    /// Creation date of the index.
+    #[serde(with = "time::serde::rfc3339")]
+    pub created_at: OffsetDateTime,
+    /// Date of the last update of the index.
+    #[serde(with = "time::serde::rfc3339")]
+    pub updated_at: OffsetDateTime,
+}
+
+impl IndexStats {
+    /// Compute the stats of an index
+    ///
+    /// # Parameters
+    ///
+    /// - rtxn: a RO transaction for the index, obtained from `Index::read_txn()`.
+    pub fn new(index: &Index, rtxn: &RoTxn) -> meilisearch_types::milli::Result<Self> {
+        Ok(IndexStats {
+            number_of_documents: index.number_of_documents(rtxn)?,
+            database_size: index.on_disk_size()?,
+            used_database_size: index.used_size()?,
+            field_distribution: index.field_distribution(rtxn)?,
+            created_at: index.created_at(rtxn)?,
+            updated_at: index.updated_at(rtxn)?,
+        })
+    }
+}

crates/milli/src/search/facet/facet_distribution.rs

@@ -219,12 +219,19 @@ impl<'a> FacetDistribution<'a> {
                 let facet_key = StrRefCodec::bytes_decode(facet_key).unwrap();
 
                 let key: (FieldId, _, &str) = (field_id, any_docid, facet_key);
-                let original_string = self
-                    .index
-                    .field_id_docid_facet_strings
-                    .get(self.rtxn, &key)?
-                    .unwrap()
-                    .to_owned();
+                let optional_original_string =
+                    self.index.field_id_docid_facet_strings.get(self.rtxn, &key)?;
+
+                let original_string = match optional_original_string {
+                    Some(original_string) => original_string.to_owned(),
+                    None => {
+                        tracing::error!(
+                            "Missing original facet string. Using the normalized facet {} instead",
+                            facet_key
+                        );
+                        facet_key.to_string()
+                    }
+                };
 
                 distribution.insert(original_string, nbr_docids);
                 if distribution.len() == self.max_values_per_facet {

crates/milli/src/thread_pool_no_abort.rs

@@ -1,4 +1,4 @@
-use std::sync::atomic::{AtomicBool, Ordering};
+use std::sync::atomic::{AtomicBool, AtomicUsize, Ordering};
 use std::sync::Arc;
 
 use rayon::{ThreadPool, ThreadPoolBuilder};
@@ -9,6 +9,8 @@ use thiserror::Error;
 #[derive(Debug)]
 pub struct ThreadPoolNoAbort {
     thread_pool: ThreadPool,
+    /// The number of active operations.
+    active_operations: AtomicUsize,
     /// Set to true if the thread pool catched a panic.
     pool_catched_panic: Arc<AtomicBool>,
 }
@@ -19,7 +21,9 @@ impl ThreadPoolNoAbort {
         OP: FnOnce() -> R + Send,
         R: Send,
     {
+        self.active_operations.fetch_add(1, Ordering::Relaxed);
         let output = self.thread_pool.install(op);
+        self.active_operations.fetch_sub(1, Ordering::Relaxed);
         // While reseting the pool panic catcher we return an error if we catched one.
         if self.pool_catched_panic.swap(false, Ordering::SeqCst) {
             Err(PanicCatched)
@@ -31,6 +35,11 @@ impl ThreadPoolNoAbort {
     pub fn current_num_threads(&self) -> usize {
         self.thread_pool.current_num_threads()
     }
+
+    /// The number of active operations.
+    pub fn active_operations(&self) -> usize {
+        self.active_operations.load(Ordering::Relaxed)
+    }
 }
 
 #[derive(Error, Debug)]
@@ -64,6 +73,10 @@ impl ThreadPoolNoAbortBuilder {
             let catched_panic = pool_catched_panic.clone();
             move |_result| catched_panic.store(true, Ordering::SeqCst)
         });
-        Ok(ThreadPoolNoAbort { thread_pool: self.0.build()?, pool_catched_panic })
+        Ok(ThreadPoolNoAbort {
+            thread_pool: self.0.build()?,
+            active_operations: AtomicUsize::new(0),
+            pool_catched_panic,
+        })
     }
 }

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

@@ -3334,6 +3334,44 @@ mod tests {
         rtxn.commit().unwrap();
     }
 
+    #[test]
+    fn incremental_update_without_changing_facet_distribution() {
+        let index = TempIndex::new();
+        index
+            .add_documents(documents!([
+                {"id": 0, "some_field": "aaa", "other_field": "aaa" },
+                {"id": 1, "some_field": "bbb", "other_field": "bbb" },
+            ]))
+            .unwrap();
+        {
+            let rtxn = index.read_txn().unwrap();
+            // count field distribution
+            let results = index.field_distribution(&rtxn).unwrap();
+            assert_eq!(Some(&2), results.get("id"));
+            assert_eq!(Some(&2), results.get("some_field"));
+            assert_eq!(Some(&2), results.get("other_field"));
+        }
+
+        let mut index = index;
+        index.index_documents_config.update_method = IndexDocumentsMethod::UpdateDocuments;
+
+        index
+            .add_documents(documents!([
+                {"id": 0, "other_field": "bbb" },
+                {"id": 1, "some_field": "ccc" },
+            ]))
+            .unwrap();
+
+        {
+            let rtxn = index.read_txn().unwrap();
+            // count field distribution
+            let results = index.field_distribution(&rtxn).unwrap();
+            assert_eq!(Some(&2), results.get("id"));
+            assert_eq!(Some(&2), results.get("some_field"));
+            assert_eq!(Some(&2), results.get("other_field"));
+        }
+    }
+
     #[test]
     fn delete_words_exact_attributes() {
         let index = TempIndex::new();

crates/milli/src/update/new/channel.rs

@@ -27,6 +27,12 @@ use crate::update::new::KvReaderFieldId;
 use crate::vector::Embedding;
 use crate::{CboRoaringBitmapCodec, DocumentId, Error, Index, InternalError};
 
+/// Note that the FrameProducer requires up to 9 bytes to
+/// encode the length, the max grant has been computed accordingly.
+///
+/// <https://docs.rs/bbqueue/latest/bbqueue/framed/index.html#frame-header>
+const MAX_FRAME_HEADER_SIZE: usize = 9;
+
 /// Creates a tuple of senders/receiver to be used by
 /// the extractors and the writer loop.
 ///
@@ -53,8 +59,9 @@ pub fn extractor_writer_bbqueue(
     bbbuffers.resize_with(current_num_threads, || BBBuffer::new(bbbuffer_capacity));
 
     let capacity = bbbuffers.first().unwrap().capacity();
-    // Read the field description to understand this
-    let capacity = capacity.checked_sub(9).unwrap();
+    // 1. Due to fragmentation in the bbbuffer, we can only accept up to half the capacity in a single message.
+    // 2. Read the documentation for `MAX_FRAME_HEADER_SIZE` for more information about why it is here.
+    let max_grant = capacity.saturating_div(2).checked_sub(MAX_FRAME_HEADER_SIZE).unwrap();
 
     let producers = ThreadLocal::with_capacity(bbbuffers.len());
     let consumers = rayon::broadcast(|bi| {
@@ -65,7 +72,7 @@ pub fn extractor_writer_bbqueue(
     });
 
     let (sender, receiver) = flume::bounded(channel_capacity);
-    let sender = ExtractorBbqueueSender { sender, producers, capacity };
+    let sender = ExtractorBbqueueSender { sender, producers, max_grant };
     let receiver = WriterBbqueueReceiver {
         receiver,
         look_at_consumer: (0..consumers.len()).cycle(),
@@ -81,13 +88,10 @@ pub struct ExtractorBbqueueSender<'a> {
     /// A memory buffer, one by thread, is used to serialize
     /// the entries directly in this shared, lock-free space.
     producers: ThreadLocal<FullySend<RefCell<FrameProducer<'a>>>>,
-    /// The capacity of this frame producer, will never be able to store more than that.
-    ///
-    /// Note that the FrameProducer requires up to 9 bytes to encode the length,
-    /// the capacity has been shrunk accordingly.
-    ///
-    /// <https://docs.rs/bbqueue/latest/bbqueue/framed/index.html#frame-header>
-    capacity: usize,
+    /// The maximum frame grant that a producer can reserve.
+    /// It will never be able to store more than that as the
+    /// buffer cannot split data into two parts.
+    max_grant: usize,
 }
 
 pub struct WriterBbqueueReceiver<'a> {
@@ -443,14 +447,14 @@ impl<'b> ExtractorBbqueueSender<'b> {
     }
 
     fn delete_vector(&self, docid: DocumentId) -> crate::Result<()> {
-        let capacity = self.capacity;
+        let max_grant = self.max_grant;
         let refcell = self.producers.get().unwrap();
         let mut producer = refcell.0.borrow_mut_or_yield();
 
         let payload_header = EntryHeader::ArroyDeleteVector(ArroyDeleteVector { docid });
         let total_length = EntryHeader::total_delete_vector_size();
-        if total_length > capacity {
-            panic!("The entry is larger ({total_length} bytes) than the BBQueue capacity ({capacity} bytes)");
+        if total_length > max_grant {
+            panic!("The entry is larger ({total_length} bytes) than the BBQueue max grant ({max_grant} bytes)");
         }
 
         // Spin loop to have a frame the size we requested.
@@ -468,7 +472,7 @@ impl<'b> ExtractorBbqueueSender<'b> {
         embedder_id: u8,
         embeddings: &[Vec<f32>],
     ) -> crate::Result<()> {
-        let capacity = self.capacity;
+        let max_grant = self.max_grant;
         let refcell = self.producers.get().unwrap();
         let mut producer = refcell.0.borrow_mut_or_yield();
 
@@ -479,7 +483,7 @@ impl<'b> ExtractorBbqueueSender<'b> {
         let arroy_set_vector = ArroySetVectors { docid, embedder_id, _padding: [0; 3] };
         let payload_header = EntryHeader::ArroySetVectors(arroy_set_vector);
         let total_length = EntryHeader::total_set_vectors_size(embeddings.len(), dimensions);
-        if total_length > capacity {
+        if total_length > max_grant {
             let mut value_file = tempfile::tempfile().map(BufWriter::new)?;
             for embedding in embeddings {
                 let mut embedding_bytes = bytemuck::cast_slice(embedding);
@@ -540,14 +544,14 @@ impl<'b> ExtractorBbqueueSender<'b> {
     where
         F: FnOnce(&mut [u8], &mut [u8]) -> crate::Result<()>,
     {
-        let capacity = self.capacity;
+        let max_grant = self.max_grant;
         let refcell = self.producers.get().unwrap();
         let mut producer = refcell.0.borrow_mut_or_yield();
 
         let operation = DbOperation { database, key_length: Some(key_length) };
         let payload_header = EntryHeader::DbOperation(operation);
         let total_length = EntryHeader::total_key_value_size(key_length, value_length);
-        if total_length > capacity {
+        if total_length > max_grant {
             let mut key_buffer = vec![0; key_length.get() as usize].into_boxed_slice();
             let value_file = tempfile::tempfile()?;
             value_file.set_len(value_length.try_into().unwrap())?;
@@ -601,7 +605,7 @@ impl<'b> ExtractorBbqueueSender<'b> {
     where
         F: FnOnce(&mut [u8]) -> crate::Result<()>,
     {
-        let capacity = self.capacity;
+        let max_grant = self.max_grant;
         let refcell = self.producers.get().unwrap();
         let mut producer = refcell.0.borrow_mut_or_yield();
 
@@ -610,8 +614,8 @@ impl<'b> ExtractorBbqueueSender<'b> {
         let operation = DbOperation { database, key_length: None };
         let payload_header = EntryHeader::DbOperation(operation);
         let total_length = EntryHeader::total_key_size(key_length);
-        if total_length > capacity {
-            panic!("The entry is larger ({total_length} bytes) than the BBQueue capacity ({capacity} bytes)");
+        if total_length > max_grant {
+            panic!("The entry is larger ({total_length} bytes) than the BBQueue max grant ({max_grant} bytes)");
         }
 
         // Spin loop to have a frame the size we requested.

crates/milli/src/update/new/extract/documents.rs

@@ -89,7 +89,8 @@ impl<'a, 'b, 'extractor> Extractor<'extractor> for DocumentsExtractor<'a, 'b> {
                             .or_default();
                         *entry -= 1;
                     }
-                    let content = update.updated();
+                    let content =
+                        update.merged(&context.rtxn, context.index, &context.db_fields_ids_map)?;
                     let geo_iter =
                         content.geo_field().transpose().map(|res| res.map(|rv| ("_geo", rv)));
                     for res in content.iter_top_level_fields().chain(geo_iter) {

crates/milli/src/update/new/extract/faceted/extract_facets.rs

@@ -283,42 +283,60 @@ impl FacetedDocidsExtractor {
 }
 
 struct DelAddFacetValue<'doc> {
-    strings: HashMap<(FieldId, BVec<'doc, u8>), DelAdd, hashbrown::DefaultHashBuilder, &'doc Bump>,
+    strings: HashMap<
+        (FieldId, &'doc str),
+        Option<BVec<'doc, u8>>,
+        hashbrown::DefaultHashBuilder,
+        &'doc Bump,
+    >,
     f64s: HashMap<(FieldId, BVec<'doc, u8>), DelAdd, hashbrown::DefaultHashBuilder, &'doc Bump>,
+    doc_alloc: &'doc Bump,
 }
 
 impl<'doc> DelAddFacetValue<'doc> {
     fn new(doc_alloc: &'doc Bump) -> Self {
-        Self { strings: HashMap::new_in(doc_alloc), f64s: HashMap::new_in(doc_alloc) }
+        Self { strings: HashMap::new_in(doc_alloc), f64s: HashMap::new_in(doc_alloc), doc_alloc }
     }
 
     fn insert_add(&mut self, fid: FieldId, value: BVec<'doc, u8>, kind: FacetKind) {
-        let cache = match kind {
-            FacetKind::String => &mut self.strings,
-            FacetKind::Number => &mut self.f64s,
-            _ => return,
-        };
-
-        let key = (fid, value);
-        if let Some(DelAdd::Deletion) = cache.get(&key) {
-            cache.remove(&key);
-        } else {
-            cache.insert(key, DelAdd::Addition);
+        match kind {
+            FacetKind::Number => {
+                let key = (fid, value);
+                if let Some(DelAdd::Deletion) = self.f64s.get(&key) {
+                    self.f64s.remove(&key);
+                } else {
+                    self.f64s.insert(key, DelAdd::Addition);
+                }
+            }
+            FacetKind::String => {
+                if let Ok(s) = std::str::from_utf8(&value) {
+                    let normalized = crate::normalize_facet(s);
+                    let truncated = self.doc_alloc.alloc_str(truncate_str(&normalized));
+                    self.strings.insert((fid, truncated), Some(value));
+                }
+            }
+            _ => (),
         }
     }
 
     fn insert_del(&mut self, fid: FieldId, value: BVec<'doc, u8>, kind: FacetKind) {
-        let cache = match kind {
-            FacetKind::String => &mut self.strings,
-            FacetKind::Number => &mut self.f64s,
-            _ => return,
-        };
-
-        let key = (fid, value);
-        if let Some(DelAdd::Addition) = cache.get(&key) {
-            cache.remove(&key);
-        } else {
-            cache.insert(key, DelAdd::Deletion);
+        match kind {
+            FacetKind::Number => {
+                let key = (fid, value);
+                if let Some(DelAdd::Addition) = self.f64s.get(&key) {
+                    self.f64s.remove(&key);
+                } else {
+                    self.f64s.insert(key, DelAdd::Deletion);
+                }
+            }
+            FacetKind::String => {
+                if let Ok(s) = std::str::from_utf8(&value) {
+                    let normalized = crate::normalize_facet(s);
+                    let truncated = self.doc_alloc.alloc_str(truncate_str(&normalized));
+                    self.strings.insert((fid, truncated), None);
+                }
+            }
+            _ => (),
         }
     }
 
@@ -329,18 +347,14 @@ impl<'doc> DelAddFacetValue<'doc> {
         doc_alloc: &Bump,
     ) -> crate::Result<()> {
         let mut buffer = bumpalo::collections::Vec::new_in(doc_alloc);
-        for ((fid, value), deladd) in self.strings {
-            if let Ok(s) = std::str::from_utf8(&value) {
-                buffer.clear();
-                buffer.extend_from_slice(&fid.to_be_bytes());
-                buffer.extend_from_slice(&docid.to_be_bytes());
-                let normalized = crate::normalize_facet(s);
-                let truncated = truncate_str(&normalized);
-                buffer.extend_from_slice(truncated.as_bytes());
-                match deladd {
-                    DelAdd::Deletion => sender.delete_facet_string(&buffer)?,
-                    DelAdd::Addition => sender.write_facet_string(&buffer, &value)?,
-                }
+        for ((fid, truncated), value) in self.strings {
+            buffer.clear();
+            buffer.extend_from_slice(&fid.to_be_bytes());
+            buffer.extend_from_slice(&docid.to_be_bytes());
+            buffer.extend_from_slice(truncated.as_bytes());
+            match &value {
+                Some(value) => sender.write_facet_string(&buffer, value)?,
+                None => sender.delete_facet_string(&buffer)?,
             }
         }
 

crates/milli/src/update/new/indexer/mod.rs

@@ -4,6 +4,7 @@ use std::sync::{OnceLock, RwLock};
 use std::thread::{self, Builder};
 
 use big_s::S;
+use bstr::ByteSlice as _;
 use bumparaw_collections::RawMap;
 use document_changes::{extract, DocumentChanges, IndexingContext};
 pub use document_deletion::DocumentDeletion;
@@ -92,24 +93,32 @@ where
         ..grenad_parameters
     };
 
-    // We compute and remove the allocated BBQueues buffers capacity from the indexing memory.
-    let minimum_capacity = 50 * 1024 * 1024 * pool.current_num_threads(); // 50 MiB
+    // 5% percent of the allocated memory for the extractors, or min 100MiB
+    // 5% percent of the allocated memory for the bbqueues, or min 50MiB
+    //
+    // Minimum capacity for bbqueues
+    let minimum_total_bbbuffer_capacity = 50 * 1024 * 1024 * pool.current_num_threads(); // 50 MiB
+    let minimum_total_extractors_capacity = minimum_total_bbbuffer_capacity * 2;
+
     let (grenad_parameters, total_bbbuffer_capacity) = grenad_parameters.max_memory.map_or(
-        (grenad_parameters, 2 * minimum_capacity), // 100 MiB by thread by default
+        (
+            GrenadParameters {
+                max_memory: Some(minimum_total_extractors_capacity),
+                ..grenad_parameters
+            },
+            minimum_total_bbbuffer_capacity,
+        ), // 100 MiB by thread by default
         |max_memory| {
-            // 2% of the indexing memory
-            let total_bbbuffer_capacity = (max_memory / 100 / 2).max(minimum_capacity);
+            let total_bbbuffer_capacity = max_memory.max(minimum_total_bbbuffer_capacity);
             let new_grenad_parameters = GrenadParameters {
-                max_memory: Some(
-                    max_memory.saturating_sub(total_bbbuffer_capacity).max(100 * 1024 * 1024),
-                ),
+                max_memory: Some(max_memory.max(minimum_total_extractors_capacity)),
                 ..grenad_parameters
             };
             (new_grenad_parameters, total_bbbuffer_capacity)
         },
     );
 
-    let (extractor_sender, mut writer_receiver) = pool
+    let (extractor_sender, writer_receiver) = pool
         .install(|| extractor_writer_bbqueue(&mut bbbuffers, total_bbbuffer_capacity, 1000))
         .unwrap();
 
@@ -424,6 +433,7 @@ where
         let mut arroy_writers = arroy_writers?;
 
         {
+            let mut writer_receiver = writer_receiver;
             let span = tracing::trace_span!(target: "indexing::write_db", "all");
             let _entered = span.enter();
 
@@ -583,7 +593,12 @@ fn write_from_bbqueue(
                     }
                     (key, None) => match database.delete(wtxn, key) {
                         Ok(false) => {
-                            unreachable!("We tried to delete an unknown key: {key:?}")
+                            tracing::error!(
+                                database_name,
+                                key_bytes = ?key,
+                                formatted_key = ?key.as_bstr(),
+                                "Attempt to delete an unknown key"
+                            );
                         }
                         Ok(_) => (),
                         Err(error) => {

crates/milli/src/update/new/mod.rs

@@ -16,6 +16,7 @@ pub mod indexer;
 mod merger;
 mod parallel_iterator_ext;
 mod ref_cell_ext;
+pub mod reindex;
 pub(crate) mod steps;
 pub(crate) mod thread_local;
 pub mod vector_document;

crates/milli/src/update/new/reindex.rs

@@ -0,0 +1,38 @@
+use heed::RwTxn;
+
+use super::document::{Document, DocumentFromDb};
+use crate::progress::{self, AtomicSubStep, Progress};
+use crate::{FieldDistribution, Index, Result};
+
+pub fn field_distribution(index: &Index, wtxn: &mut RwTxn<'_>, progress: &Progress) -> Result<()> {
+    let mut distribution = FieldDistribution::new();
+
+    let document_count = index.number_of_documents(wtxn)?;
+    let field_id_map = index.fields_ids_map(wtxn)?;
+
+    let (update_document_count, sub_step) =
+        AtomicSubStep::<progress::Document>::new(document_count as u32);
+    progress.update_progress(sub_step);
+
+    let docids = index.documents_ids(wtxn)?;
+
+    for docid in docids {
+        update_document_count.fetch_add(1, std::sync::atomic::Ordering::Relaxed);
+
+        let Some(document) = DocumentFromDb::new(docid, wtxn, index, &field_id_map)? else {
+            continue;
+        };
+        let geo_iter = document.geo_field().transpose().map(|res| res.map(|rv| ("_geo", rv)));
+        for res in document.iter_top_level_fields().chain(geo_iter) {
+            let (field_name, _) = res?;
+            if let Some(count) = distribution.get_mut(field_name) {
+                *count += 1;
+            } else {
+                distribution.insert(field_name.to_owned(), 1);
+            }
+        }
+    }
+
+    index.put_field_distribution(wtxn, &distribution)?;
+    Ok(())
+}

crates/milli/src/vector/ollama.rs

@@ -5,7 +5,7 @@ use rayon::slice::ParallelSlice as _;
 
 use super::error::{EmbedError, EmbedErrorKind, NewEmbedderError, NewEmbedderErrorKind};
 use super::rest::{Embedder as RestEmbedder, EmbedderOptions as RestEmbedderOptions};
-use super::DistributionShift;
+use super::{DistributionShift, REQUEST_PARALLELISM};
 use crate::error::FaultSource;
 use crate::vector::Embedding;
 use crate::ThreadPoolNoAbort;
@@ -113,20 +113,30 @@ impl Embedder {
         texts: &[&str],
         threads: &ThreadPoolNoAbort,
     ) -> Result<Vec<Vec<f32>>, EmbedError> {
-        threads
-            .install(move || {
-                let embeddings: Result<Vec<Vec<Embedding>>, _> = texts
-                    .par_chunks(self.prompt_count_in_chunk_hint())
-                    .map(move |chunk| self.embed(chunk, None))
-                    .collect();
+        if threads.active_operations() >= REQUEST_PARALLELISM {
+            let embeddings: Result<Vec<Vec<Embedding>>, _> = texts
+                .chunks(self.prompt_count_in_chunk_hint())
+                .map(move |chunk| self.embed(chunk, None))
+                .collect();
 
-                let embeddings = embeddings?;
-                Ok(embeddings.into_iter().flatten().collect())
-            })
-            .map_err(|error| EmbedError {
-                kind: EmbedErrorKind::PanicInThreadPool(error),
-                fault: FaultSource::Bug,
-            })?
+            let embeddings = embeddings?;
+            Ok(embeddings.into_iter().flatten().collect())
+        } else {
+            threads
+                .install(move || {
+                    let embeddings: Result<Vec<Vec<Embedding>>, _> = texts
+                        .par_chunks(self.prompt_count_in_chunk_hint())
+                        .map(move |chunk| self.embed(chunk, None))
+                        .collect();
+
+                    let embeddings = embeddings?;
+                    Ok(embeddings.into_iter().flatten().collect())
+                })
+                .map_err(|error| EmbedError {
+                    kind: EmbedErrorKind::PanicInThreadPool(error),
+                    fault: FaultSource::Bug,
+                })?
+        }
     }
 
     pub fn chunk_count_hint(&self) -> usize {

crates/milli/src/vector/openai.rs

@@ -6,7 +6,7 @@ use rayon::slice::ParallelSlice as _;
 
 use super::error::{EmbedError, NewEmbedderError};
 use super::rest::{Embedder as RestEmbedder, EmbedderOptions as RestEmbedderOptions};
-use super::DistributionShift;
+use super::{DistributionShift, REQUEST_PARALLELISM};
 use crate::error::FaultSource;
 use crate::vector::error::EmbedErrorKind;
 use crate::vector::Embedding;
@@ -270,20 +270,29 @@ impl Embedder {
         texts: &[&str],
         threads: &ThreadPoolNoAbort,
     ) -> Result<Vec<Vec<f32>>, EmbedError> {
-        threads
-            .install(move || {
-                let embeddings: Result<Vec<Vec<Embedding>>, _> = texts
-                    .par_chunks(self.prompt_count_in_chunk_hint())
-                    .map(move |chunk| self.embed(chunk, None))
-                    .collect();
+        if threads.active_operations() >= REQUEST_PARALLELISM {
+            let embeddings: Result<Vec<Vec<Embedding>>, _> = texts
+                .chunks(self.prompt_count_in_chunk_hint())
+                .map(move |chunk| self.embed(chunk, None))
+                .collect();
+            let embeddings = embeddings?;
+            Ok(embeddings.into_iter().flatten().collect())
+        } else {
+            threads
+                .install(move || {
+                    let embeddings: Result<Vec<Vec<Embedding>>, _> = texts
+                        .par_chunks(self.prompt_count_in_chunk_hint())
+                        .map(move |chunk| self.embed(chunk, None))
+                        .collect();
 
-                let embeddings = embeddings?;
-                Ok(embeddings.into_iter().flatten().collect())
-            })
-            .map_err(|error| EmbedError {
-                kind: EmbedErrorKind::PanicInThreadPool(error),
-                fault: FaultSource::Bug,
-            })?
+                    let embeddings = embeddings?;
+                    Ok(embeddings.into_iter().flatten().collect())
+                })
+                .map_err(|error| EmbedError {
+                    kind: EmbedErrorKind::PanicInThreadPool(error),
+                    fault: FaultSource::Bug,
+                })?
+        }
     }
 
     pub fn chunk_count_hint(&self) -> usize {

crates/milli/src/vector/rest.rs

@@ -203,20 +203,30 @@ impl Embedder {
         texts: &[&str],
         threads: &ThreadPoolNoAbort,
     ) -> Result<Vec<Embedding>, EmbedError> {
-        threads
-            .install(move || {
-                let embeddings: Result<Vec<Vec<Embedding>>, _> = texts
-                    .par_chunks(self.prompt_count_in_chunk_hint())
-                    .map(move |chunk| self.embed_ref(chunk, None))
-                    .collect();
+        if threads.active_operations() >= REQUEST_PARALLELISM {
+            let embeddings: Result<Vec<Vec<Embedding>>, _> = texts
+                .chunks(self.prompt_count_in_chunk_hint())
+                .map(move |chunk| self.embed_ref(chunk, None))
+                .collect();
 
-                let embeddings = embeddings?;
-                Ok(embeddings.into_iter().flatten().collect())
-            })
-            .map_err(|error| EmbedError {
-                kind: EmbedErrorKind::PanicInThreadPool(error),
-                fault: FaultSource::Bug,
-            })?
+            let embeddings = embeddings?;
+            Ok(embeddings.into_iter().flatten().collect())
+        } else {
+            threads
+                .install(move || {
+                    let embeddings: Result<Vec<Vec<Embedding>>, _> = texts
+                        .par_chunks(self.prompt_count_in_chunk_hint())
+                        .map(move |chunk| self.embed_ref(chunk, None))
+                        .collect();
+
+                    let embeddings = embeddings?;
+                    Ok(embeddings.into_iter().flatten().collect())
+                })
+                .map_err(|error| EmbedError {
+                    kind: EmbedErrorKind::PanicInThreadPool(error),
+                    fault: FaultSource::Bug,
+                })?
+        }
     }
 
     pub fn chunk_count_hint(&self) -> usize {