Revert thread_pool type back to Option in config

crates/index-scheduler/src/scheduler/process_index_operation.rs

@@ -115,8 +115,7 @@ impl IndexScheduler {
 
                 let local_pool;
                 let indexer_config = self.index_mapper.indexer_config();
-                let pool_guard = indexer_config.thread_pool.read().unwrap();
+                let pool = match &indexer_config.thread_pool {
-                let pool = match &*pool_guard {
                     Some(pool) => pool,
                     None => {
                         local_pool = ThreadPoolNoAbortBuilder::new()
@@ -269,8 +268,7 @@ impl IndexScheduler {
                 if task.error.is_none() {
                     let local_pool;
                     let indexer_config = self.index_mapper.indexer_config();
-                    let pool_guard = indexer_config.thread_pool.read().unwrap();
+                    let pool = match &indexer_config.thread_pool {
-                    let pool = match &*pool_guard {
                         Some(pool) => pool,
                         None => {
                             local_pool = ThreadPoolNoAbortBuilder::new()
@@ -433,8 +431,7 @@ impl IndexScheduler {
                 if !tasks.iter().all(|res| res.error.is_some()) {
                     let local_pool;
                     let indexer_config = self.index_mapper.indexer_config();
-                    let pool_guard = indexer_config.thread_pool.read().unwrap();
+                    let pool = match &indexer_config.thread_pool {
-                    let pool = match &*pool_guard {
                         Some(pool) => pool,
                         None => {
                             local_pool = ThreadPoolNoAbortBuilder::new()

crates/meilisearch/src/lib.rs

@@ -37,7 +37,7 @@ use index_scheduler::{IndexScheduler, IndexSchedulerOptions};
 use meilisearch_auth::{open_auth_store_env, AuthController};
 use meilisearch_types::milli::constants::VERSION_MAJOR;
 use meilisearch_types::milli::documents::{DocumentsBatchBuilder, DocumentsBatchReader};
-use meilisearch_types::milli::update::{IndexDocumentsConfig, IndexDocumentsMethod};
+use meilisearch_types::milli::update::{IndexDocumentsConfig, IndexDocumentsMethod, IndexerConfig};
 use meilisearch_types::milli::ThreadPoolNoAbortBuilder;
 use meilisearch_types::settings::apply_settings_to_builder;
 use meilisearch_types::tasks::KindWithContent;
@@ -504,10 +504,10 @@ fn import_dump(
     let network = dump_reader.network()?.cloned().unwrap_or_default();
     index_scheduler.put_network(network)?;
 
-    let indexer_config = index_scheduler.indexer_config();
+    let mut indexer_config = IndexerConfig::clone_no_threadpool(index_scheduler.indexer_config());
 
-    // Use all cpus to index a dump
+    // 3.1 Use all cpus to index the import dump
-    let pool_before = {
+    indexer_config.thread_pool = {
         let all_cpus = num_cpus::get();
 
         let temp_pool = ThreadPoolNoAbortBuilder::new()
@@ -515,7 +515,7 @@ fn import_dump(
             .num_threads(all_cpus)
             .build()?;
 
-        indexer_config.thread_pool.write().unwrap().replace(temp_pool)
+        Some(temp_pool)
     };
 
     // /!\ The tasks must be imported AFTER importing the indexes or else the scheduler might
@@ -533,7 +533,7 @@ fn import_dump(
 
         let mut wtxn = index.write_txn()?;
 
-        let mut builder = milli::update::Settings::new(&mut wtxn, &index, indexer_config);
+        let mut builder = milli::update::Settings::new(&mut wtxn, &index, &indexer_config);
         // 4.1 Import the primary key if there is one.
         if let Some(ref primary_key) = metadata.primary_key {
             builder.set_primary_key(primary_key.to_string());
@@ -568,7 +568,7 @@ fn import_dump(
         let builder = milli::update::IndexDocuments::new(
             &mut wtxn,
             &index,
-            indexer_config,
+            &indexer_config,
             IndexDocumentsConfig {
                 update_method: IndexDocumentsMethod::ReplaceDocuments,
                 ..Default::default()
@@ -589,12 +589,6 @@ fn import_dump(
         index_scheduler.refresh_index_stats(&uid)?;
     }
 
-    // Restore original thread pool after dump
-    {
-        let mut guard = indexer_config.thread_pool.write().unwrap();
-        *guard = pool_before;
-    }
-
     // 5. Import the queue
     let mut index_scheduler_dump = index_scheduler.register_dumped_task()?;
     // 5.1. Import the batches

crates/meilisearch/src/option.rs

@@ -6,7 +6,7 @@ use std::num::{NonZeroUsize, ParseIntError};
 use std::ops::Deref;
 use std::path::PathBuf;
 use std::str::FromStr;
-use std::sync::{Arc, RwLock};
+use std::sync::Arc;
 use std::{env, fmt, fs};
 
 use byte_unit::{Byte, ParseError, UnitType};
@@ -765,7 +765,7 @@ impl TryFrom<&IndexerOpts> for IndexerConfig {
         Ok(Self {
             log_every_n: Some(DEFAULT_LOG_EVERY_N),
             max_memory: other.max_indexing_memory.map(|b| b.as_u64() as usize),
-            thread_pool: RwLock::new(Some(thread_pool)),
+            thread_pool: Some(thread_pool),
             max_positions_per_attributes: None,
             skip_index_budget: other.skip_index_budget,
             ..Default::default()

crates/milli/src/index.rs

@@ -1936,8 +1936,7 @@ pub(crate) mod tests {
         ) -> Result<(), crate::error::Error> {
             let local_pool;
             let indexer_config = &self.indexer_config;
-            let pool_guard = indexer_config.thread_pool.read().unwrap();
+            let pool = match &indexer_config.thread_pool {
-            let pool = match &*pool_guard {
                 Some(pool) => pool,
                 None => {
                     local_pool = ThreadPoolNoAbortBuilder::new().build().unwrap();
@@ -2031,8 +2030,7 @@ pub(crate) mod tests {
         ) -> Result<(), crate::error::Error> {
             let local_pool;
             let indexer_config = &self.indexer_config;
-            let pool_guard = indexer_config.thread_pool.read().unwrap();
+            let pool = match &indexer_config.thread_pool {
-            let pool = match &*pool_guard {
                 Some(pool) => pool,
                 None => {
                     local_pool = ThreadPoolNoAbortBuilder::new().build().unwrap();
@@ -2111,8 +2109,7 @@ pub(crate) mod tests {
 
         let local_pool;
         let indexer_config = &index.indexer_config;
-        let pool_guard = indexer_config.thread_pool.read().unwrap();
+        let pool = match &indexer_config.thread_pool {
-        let pool = match &*pool_guard {
             Some(pool) => pool,
             None => {
                 local_pool = ThreadPoolNoAbortBuilder::new().build().unwrap();

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

@@ -228,10 +228,8 @@ where
         let possible_embedding_mistakes =
             crate::vector::error::PossibleEmbeddingMistakes::new(&field_distribution);
 
-        let pool_guard = self.indexer_config.thread_pool.read().unwrap();
-
         let backup_pool;
-        let pool = match &*pool_guard {
+        let pool = match self.indexer_config.thread_pool {
             Some(ref pool) => pool,
             None => {
                 // We initialize a backup pool with the default

crates/milli/src/update/indexer_config.rs

@@ -1,5 +1,3 @@
-use std::sync::RwLock;
-
 use grenad::CompressionType;
 
 use super::GrenadParameters;
@@ -13,7 +11,7 @@ pub struct IndexerConfig {
     pub max_memory: Option<usize>,
     pub chunk_compression_type: CompressionType,
     pub chunk_compression_level: Option<u32>,
-    pub thread_pool: RwLock<Option<ThreadPoolNoAbort>>,
+    pub thread_pool: Option<ThreadPoolNoAbort>,
     pub max_positions_per_attributes: Option<u32>,
     pub skip_index_budget: bool,
 }
@@ -27,6 +25,20 @@ impl IndexerConfig {
             max_nb_chunks: self.max_nb_chunks,
         }
     }
+
+    pub fn clone_no_threadpool(other: &IndexerConfig) -> Self {
+        Self {
+            log_every_n: other.log_every_n.clone(),
+            max_nb_chunks: other.max_nb_chunks.clone(),
+            documents_chunk_size: other.documents_chunk_size.clone(),
+            max_memory: other.max_memory.clone(),
+            chunk_compression_type: other.chunk_compression_type.clone(),
+            chunk_compression_level: other.chunk_compression_level.clone(),
+            max_positions_per_attributes: other.max_positions_per_attributes.clone(),
+            skip_index_budget: other.skip_index_budget.clone(),
+            thread_pool: None,
+        }
+    }
 }
 
 impl Default for IndexerConfig {
@@ -38,7 +50,7 @@ impl Default for IndexerConfig {
             max_memory: None,
             chunk_compression_type: CompressionType::None,
             chunk_compression_level: None,
-            thread_pool: RwLock::new(None),
+            thread_pool: None,
             max_positions_per_attributes: None,
             skip_index_budget: false,
         }