Merge #4042

4042: Implements the new replication parameters r=ManyTheFish a=irevoire

### This PR implements the necessary parameters for the High Availability

- [ ] Update the spec

Introduce a new CLI flag called `--experimental-replication-parameters` that changes a few behaviors in the engine:
- [The auto-deletion of tasks is disabled](https://specs.meilisearch.com/specifications/text/0060-tasks-api.html#_2-technical-details)
- Upon registering a task, you can choose its task ID by sending a new header: `TaskId: 456645`. It must be a valid number, which must be superior to the last task id ever seen.
- Add the ability to « dry-register » a task. That means meilisearch will answer to you with a valid task ID like everything went well, but won’t actually write anything in the database. To do that, you need to use the `DryRun: true` header.

----

Old prototype `prototype-custom-task-id-0`:
-  Adds the capability to specify your own task ID via the `TaskId` http header
- Make the task IDs a u64 instead of a u32


Co-authored-by: Tamo <tamo@meilisearch.com>

file-store/src/lib.rs

@@ -1,5 +1,5 @@
 use std::fs::File as StdFile;
-use std::ops::{Deref, DerefMut};
+use std::io::Write;
 use std::path::{Path, PathBuf};
 use std::str::FromStr;
 
@@ -22,20 +22,6 @@ pub enum Error {
 
 pub type Result<T> = std::result::Result<T, Error>;
 
-impl Deref for File {
-    type Target = NamedTempFile;
-
-    fn deref(&self) -> &Self::Target {
-        &self.file
-    }
-}
-
-impl DerefMut for File {
-    fn deref_mut(&mut self) -> &mut Self::Target {
-        &mut self.file
-    }
-}
-
 #[derive(Clone, Debug)]
 pub struct FileStore {
     path: PathBuf,
@@ -56,7 +42,7 @@ impl FileStore {
         let file = NamedTempFile::new_in(&self.path)?;
         let uuid = Uuid::new_v4();
         let path = self.path.join(uuid.to_string());
-        let update_file = File { file, path };
+        let update_file = File { file: Some(file), path };
 
         Ok((uuid, update_file))
     }
@@ -67,7 +53,7 @@ impl FileStore {
         let file = NamedTempFile::new_in(&self.path)?;
         let uuid = Uuid::from_u128(uuid);
         let path = self.path.join(uuid.to_string());
-        let update_file = File { file, path };
+        let update_file = File { file: Some(file), path };
 
         Ok((uuid, update_file))
     }
@@ -136,16 +122,40 @@ impl FileStore {
 
 pub struct File {
     path: PathBuf,
-    file: NamedTempFile,
+    file: Option<NamedTempFile>,
 }
 
 impl File {
+    pub fn dry_file() -> Result<Self> {
+        Ok(Self { path: PathBuf::new(), file: None })
+    }
+
     pub fn persist(self) -> Result<()> {
-        self.file.persist(&self.path)?;
+        if let Some(file) = self.file {
+            file.persist(&self.path)?;
+        }
         Ok(())
     }
 }
 
+impl Write for File {
+    fn write(&mut self, buf: &[u8]) -> std::io::Result<usize> {
+        if let Some(file) = self.file.as_mut() {
+            file.write(buf)
+        } else {
+            Ok(buf.len())
+        }
+    }
+
+    fn flush(&mut self) -> std::io::Result<()> {
+        if let Some(file) = self.file.as_mut() {
+            file.flush()
+        } else {
+            Ok(())
+        }
+    }
+}
+
 #[cfg(test)]
 mod test {
     use std::io::Write;

index-scheduler/src/error.rs

@@ -48,6 +48,8 @@ impl From<DateField> for Code {
 pub enum Error {
     #[error("{1}")]
     WithCustomErrorCode(Code, Box<Self>),
+    #[error("Received bad task id: {received} should be >= to {expected}.")]
+    BadTaskId { received: TaskId, expected: TaskId },
     #[error("Index `{0}` not found.")]
     IndexNotFound(String),
     #[error("Index `{0}` already exists.")]
@@ -161,6 +163,7 @@ impl Error {
         match self {
             Error::IndexNotFound(_)
             | Error::WithCustomErrorCode(_, _)
+            | Error::BadTaskId { .. }
             | Error::IndexAlreadyExists(_)
             | Error::SwapDuplicateIndexFound(_)
             | Error::SwapDuplicateIndexesFound(_)
@@ -205,6 +208,7 @@ impl ErrorCode for Error {
     fn error_code(&self) -> Code {
         match self {
             Error::WithCustomErrorCode(code, _) => *code,
+            Error::BadTaskId { .. } => Code::BadRequest,
             Error::IndexNotFound(_) => Code::IndexNotFound,
             Error::IndexAlreadyExists(_) => Code::IndexAlreadyExists,
             Error::SwapDuplicateIndexesFound(_) => Code::InvalidSwapDuplicateIndexFound,

index-scheduler/src/insta_snapshot.rs

@@ -15,6 +15,7 @@ pub fn snapshot_index_scheduler(scheduler: &IndexScheduler) -> String {
 
     let IndexScheduler {
         autobatching_enabled,
+        cleanup_enabled: _,
         must_stop_processing: _,
         processing_tasks,
         file_store,

index-scheduler/src/snapshots/lib.rs/test_disable_auto_deletion_of_tasks/task_deletion_have_not_been_enqueued.snap

@@ -0,0 +1,90 @@
+---
+source: index-scheduler/src/lib.rs
+---
+[
+  {
+    "uid": 0,
+    "enqueuedAt": "[date]",
+    "startedAt": "[date]",
+    "finishedAt": "[date]",
+    "error": null,
+    "canceledBy": null,
+    "details": {
+      "IndexInfo": {
+        "primary_key": null
+      }
+    },
+    "status": "succeeded",
+    "kind": {
+      "indexCreation": {
+        "index_uid": "doggo",
+        "primary_key": null
+      }
+    }
+  },
+  {
+    "uid": 1,
+    "enqueuedAt": "[date]",
+    "startedAt": "[date]",
+    "finishedAt": "[date]",
+    "error": {
+      "message": "Index `doggo` already exists.",
+      "code": "index_already_exists",
+      "type": "invalid_request",
+      "link": "https://docs.meilisearch.com/errors#index_already_exists"
+    },
+    "canceledBy": null,
+    "details": {
+      "IndexInfo": {
+        "primary_key": null
+      }
+    },
+    "status": "failed",
+    "kind": {
+      "indexCreation": {
+        "index_uid": "doggo",
+        "primary_key": null
+      }
+    }
+  },
+  {
+    "uid": 2,
+    "enqueuedAt": "[date]",
+    "startedAt": "[date]",
+    "finishedAt": "[date]",
+    "error": null,
+    "canceledBy": null,
+    "details": {
+      "IndexInfo": {
+        "primary_key": null
+      }
+    },
+    "status": "enqueued",
+    "kind": {
+      "indexCreation": {
+        "index_uid": "doggo",
+        "primary_key": null
+      }
+    }
+  },
+  {
+    "uid": 3,
+    "enqueuedAt": "[date]",
+    "startedAt": "[date]",
+    "finishedAt": "[date]",
+    "error": null,
+    "canceledBy": null,
+    "details": {
+      "IndexInfo": {
+        "primary_key": null
+      }
+    },
+    "status": "enqueued",
+    "kind": {
+      "indexCreation": {
+        "index_uid": "doggo",
+        "primary_key": null
+      }
+    }
+  }
+]

index-scheduler/src/snapshots/lib.rs/test_disable_auto_deletion_of_tasks/task_queue_is_full.snap

@@ -0,0 +1,90 @@
+---
+source: index-scheduler/src/lib.rs
+---
+[
+  {
+    "uid": 0,
+    "enqueuedAt": "[date]",
+    "startedAt": "[date]",
+    "finishedAt": "[date]",
+    "error": null,
+    "canceledBy": null,
+    "details": {
+      "IndexInfo": {
+        "primary_key": null
+      }
+    },
+    "status": "succeeded",
+    "kind": {
+      "indexCreation": {
+        "index_uid": "doggo",
+        "primary_key": null
+      }
+    }
+  },
+  {
+    "uid": 1,
+    "enqueuedAt": "[date]",
+    "startedAt": "[date]",
+    "finishedAt": "[date]",
+    "error": {
+      "message": "Index `doggo` already exists.",
+      "code": "index_already_exists",
+      "type": "invalid_request",
+      "link": "https://docs.meilisearch.com/errors#index_already_exists"
+    },
+    "canceledBy": null,
+    "details": {
+      "IndexInfo": {
+        "primary_key": null
+      }
+    },
+    "status": "failed",
+    "kind": {
+      "indexCreation": {
+        "index_uid": "doggo",
+        "primary_key": null
+      }
+    }
+  },
+  {
+    "uid": 2,
+    "enqueuedAt": "[date]",
+    "startedAt": "[date]",
+    "finishedAt": "[date]",
+    "error": null,
+    "canceledBy": null,
+    "details": {
+      "IndexInfo": {
+        "primary_key": null
+      }
+    },
+    "status": "enqueued",
+    "kind": {
+      "indexCreation": {
+        "index_uid": "doggo",
+        "primary_key": null
+      }
+    }
+  },
+  {
+    "uid": 3,
+    "enqueuedAt": "[date]",
+    "startedAt": "[date]",
+    "finishedAt": "[date]",
+    "error": null,
+    "canceledBy": null,
+    "details": {
+      "IndexInfo": {
+        "primary_key": null
+      }
+    },
+    "status": "enqueued",
+    "kind": {
+      "indexCreation": {
+        "index_uid": "doggo",
+        "primary_key": null
+      }
+    }
+  }
+]

meilisearch-types/src/document_formats.rs

@@ -1,6 +1,6 @@
 use std::fmt::{self, Debug, Display};
 use std::fs::File;
-use std::io::{self, Seek, Write};
+use std::io::{self, BufWriter, Write};
 use std::marker::PhantomData;
 
 use memmap2::MmapOptions;
@@ -104,8 +104,8 @@ impl ErrorCode for DocumentFormatError {
 }
 
 /// Reads CSV from input and write an obkv batch to writer.
-pub fn read_csv(file: &File, writer: impl Write + Seek, delimiter: u8) -> Result<u64> {
+pub fn read_csv(file: &File, writer: impl Write, delimiter: u8) -> Result<u64> {
-    let mut builder = DocumentsBatchBuilder::new(writer);
+    let mut builder = DocumentsBatchBuilder::new(BufWriter::new(writer));
     let mmap = unsafe { MmapOptions::new().map(file)? };
     let csv = csv::ReaderBuilder::new().delimiter(delimiter).from_reader(mmap.as_ref());
     builder.append_csv(csv).map_err(|e| (PayloadType::Csv { delimiter }, e))?;
@@ -116,9 +116,9 @@ pub fn read_csv(file: &File, writer: impl Write + Seek, delimiter: u8) -> Result
     Ok(count as u64)
 }
 
-/// Reads JSON from temporary file  and write an obkv batch to writer.
+/// Reads JSON from temporary file and write an obkv batch to writer.
-pub fn read_json(file: &File, writer: impl Write + Seek) -> Result<u64> {
+pub fn read_json(file: &File, writer: impl Write) -> Result<u64> {
-    let mut builder = DocumentsBatchBuilder::new(writer);
+    let mut builder = DocumentsBatchBuilder::new(BufWriter::new(writer));
     let mmap = unsafe { MmapOptions::new().map(file)? };
     let mut deserializer = serde_json::Deserializer::from_slice(&mmap);
 
@@ -151,8 +151,8 @@ pub fn read_json(file: &File, writer: impl Write + Seek) -> Result<u64> {
 }
 
 /// Reads JSON from temporary file  and write an obkv batch to writer.
-pub fn read_ndjson(file: &File, writer: impl Write + Seek) -> Result<u64> {
+pub fn read_ndjson(file: &File, writer: impl Write) -> Result<u64> {
-    let mut builder = DocumentsBatchBuilder::new(writer);
+    let mut builder = DocumentsBatchBuilder::new(BufWriter::new(writer));
     let mmap = unsafe { MmapOptions::new().map(file)? };
 
     for result in serde_json::Deserializer::from_slice(&mmap).into_iter() {

meilisearch/src/analytics/segment_analytics.rs

@@ -250,6 +250,7 @@ impl super::Analytics for SegmentAnalytics {
 struct Infos {
     env: String,
     experimental_enable_metrics: bool,
+    experimental_replication_parameters: bool,
     experimental_enable_logs_route: bool,
     experimental_reduce_indexing_memory_usage: bool,
     experimental_max_number_of_batched_tasks: usize,
@@ -288,6 +289,7 @@ impl From<Opt> for Infos {
         let Opt {
             db_path,
             experimental_enable_metrics,
+            experimental_replication_parameters,
             experimental_enable_logs_route,
             experimental_reduce_indexing_memory_usage,
             experimental_max_number_of_batched_tasks,
@@ -335,6 +337,7 @@ impl From<Opt> for Infos {
         Self {
             env,
             experimental_enable_metrics,
+            experimental_replication_parameters,
             experimental_enable_logs_route,
             experimental_reduce_indexing_memory_usage,
             db_path: db_path != PathBuf::from("./data.ms"),

meilisearch/src/extractors/sequential_extractor.rs

@@ -131,6 +131,7 @@ gen_seq! { SeqFromRequestFut3; A B C }
 gen_seq! { SeqFromRequestFut4; A B C D }
 gen_seq! { SeqFromRequestFut5; A B C D E }
 gen_seq! { SeqFromRequestFut6; A B C D E F }
+gen_seq! { SeqFromRequestFut7; A B C D E F G }
 
 pin_project! {
     #[project = ExtractProj]

meilisearch/src/lib.rs

@@ -251,7 +251,9 @@ pub fn setup_meilisearch(opt: &Opt) -> anyhow::Result<(Arc<IndexScheduler>, Arc<
             .name(String::from("register-snapshot-tasks"))
             .spawn(move || loop {
                 thread::sleep(snapshot_delay);
-                if let Err(e) = index_scheduler.register(KindWithContent::SnapshotCreation) {
+                if let Err(e) =
+                    index_scheduler.register(KindWithContent::SnapshotCreation, None, false)
+                {
                     error!("Error while registering snapshot: {}", e);
                 }
             })
@@ -286,6 +288,7 @@ fn open_or_create_database_unchecked(
             enable_mdb_writemap: opt.experimental_reduce_indexing_memory_usage,
             indexer_config: (&opt.indexer_options).try_into()?,
             autobatching_enabled: true,
+            cleanup_enabled: !opt.experimental_replication_parameters,
             max_number_of_tasks: 1_000_000,
             max_number_of_batched_tasks: opt.experimental_max_number_of_batched_tasks,
             index_growth_amount: byte_unit::Byte::from_str("10GiB").unwrap().get_bytes() as usize,
@@ -453,6 +456,7 @@ pub fn configure_data(
         .app_data(auth)
         .app_data(web::Data::from(analytics))
         .app_data(web::Data::new(logs))
+        .app_data(web::Data::new(opt.clone()))
         .app_data(
             web::JsonConfig::default()
                 .limit(http_payload_size_limit)

meilisearch/src/option.rs

@@ -51,6 +51,7 @@ const MEILI_IGNORE_MISSING_DUMP: &str = "MEILI_IGNORE_MISSING_DUMP";
 const MEILI_IGNORE_DUMP_IF_DB_EXISTS: &str = "MEILI_IGNORE_DUMP_IF_DB_EXISTS";
 const MEILI_DUMP_DIR: &str = "MEILI_DUMP_DIR";
 const MEILI_LOG_LEVEL: &str = "MEILI_LOG_LEVEL";
+const MEILI_EXPERIMENTAL_REPLICATION_PARAMETERS: &str = "MEILI_EXPERIMENTAL_REPLICATION_PARAMETERS";
 const MEILI_EXPERIMENTAL_ENABLE_LOGS_ROUTE: &str = "MEILI_EXPERIMENTAL_ENABLE_LOGS_ROUTE";
 const MEILI_EXPERIMENTAL_ENABLE_METRICS: &str = "MEILI_EXPERIMENTAL_ENABLE_METRICS";
 const MEILI_EXPERIMENTAL_REDUCE_INDEXING_MEMORY_USAGE: &str =
@@ -317,6 +318,16 @@ pub struct Opt {
     #[serde(default)]
     pub experimental_enable_logs_route: bool,
 
+    /// Enable multiple features that helps you to run meilisearch in a replicated context.
+    /// For more information, see: <https://github.com/orgs/meilisearch/discussions/725>
+    ///
+    /// - /!\ Disable the automatic clean up of old processed tasks, you're in charge of that now
+    /// - Lets you specify a custom task ID upon registering a task
+    /// - Lets you execute dry-register a task (get an answer from the route but nothing is actually registered in meilisearch and it won't be processed)
+    #[clap(long, env = MEILI_EXPERIMENTAL_REPLICATION_PARAMETERS)]
+    #[serde(default)]
+    pub experimental_replication_parameters: bool,
+
     /// Experimental RAM reduction during indexing, do not use in production, see: <https://github.com/meilisearch/product/discussions/652>
     #[clap(long, env = MEILI_EXPERIMENTAL_REDUCE_INDEXING_MEMORY_USAGE)]
     #[serde(default)]
@@ -423,6 +434,7 @@ impl Opt {
             no_analytics,
             experimental_enable_metrics,
             experimental_enable_logs_route,
+            experimental_replication_parameters,
             experimental_reduce_indexing_memory_usage,
         } = self;
         export_to_env_if_not_present(MEILI_DB_PATH, db_path);
@@ -479,6 +491,10 @@ impl Opt {
             MEILI_EXPERIMENTAL_ENABLE_METRICS,
             experimental_enable_metrics.to_string(),
         );
+        export_to_env_if_not_present(
+            MEILI_EXPERIMENTAL_REPLICATION_PARAMETERS,
+            experimental_replication_parameters.to_string(),
+        );
         export_to_env_if_not_present(
             MEILI_EXPERIMENTAL_ENABLE_LOGS_ROUTE,
             experimental_enable_logs_route.to_string(),

meilisearch/src/routes/dump.rs

@@ -11,7 +11,8 @@ use crate::analytics::Analytics;
 use crate::extractors::authentication::policies::*;
 use crate::extractors::authentication::GuardedData;
 use crate::extractors::sequential_extractor::SeqHandler;
-use crate::routes::SummarizedTaskView;
+use crate::routes::{get_task_id, is_dry_run, SummarizedTaskView};
+use crate::Opt;
 
 pub fn configure(cfg: &mut web::ServiceConfig) {
     cfg.service(web::resource("").route(web::post().to(SeqHandler(create_dump))));
@@ -21,6 +22,7 @@ pub async fn create_dump(
     index_scheduler: GuardedData<ActionPolicy<{ actions::DUMPS_CREATE }>, Data<IndexScheduler>>,
     auth_controller: GuardedData<ActionPolicy<{ actions::DUMPS_CREATE }>, Data<AuthController>>,
     req: HttpRequest,
+    opt: web::Data<Opt>,
     analytics: web::Data<dyn Analytics>,
 ) -> Result<HttpResponse, ResponseError> {
     analytics.publish("Dump Created".to_string(), json!({}), Some(&req));
@@ -29,8 +31,12 @@ pub async fn create_dump(
         keys: auth_controller.list_keys()?,
         instance_uid: analytics.instance_uid().cloned(),
     };
+    let uid = get_task_id(&req, &opt)?;
+    let dry_run = is_dry_run(&req, &opt)?;
     let task: SummarizedTaskView =
-        tokio::task::spawn_blocking(move || index_scheduler.register(task)).await??.into();
+        tokio::task::spawn_blocking(move || index_scheduler.register(task, uid, dry_run))
+            .await??
+            .into();
 
     debug!(returns = ?task, "Create dump");
     Ok(HttpResponse::Accepted().json(task))

meilisearch/src/routes/indexes/documents.rs

@@ -7,7 +7,7 @@ use bstr::ByteSlice as _;
 use deserr::actix_web::{AwebJson, AwebQueryParameter};
 use deserr::Deserr;
 use futures::StreamExt;
-use index_scheduler::IndexScheduler;
+use index_scheduler::{IndexScheduler, TaskId};
 use meilisearch_types::deserr::query_params::Param;
 use meilisearch_types::deserr::{DeserrJsonError, DeserrQueryParamError};
 use meilisearch_types::document_formats::{read_csv, read_json, read_ndjson, PayloadType};
@@ -36,8 +36,11 @@ use crate::extractors::authentication::policies::*;
 use crate::extractors::authentication::GuardedData;
 use crate::extractors::payload::Payload;
 use crate::extractors::sequential_extractor::SeqHandler;
-use crate::routes::{PaginationView, SummarizedTaskView, PAGINATION_DEFAULT_LIMIT};
+use crate::routes::{
+    get_task_id, is_dry_run, PaginationView, SummarizedTaskView, PAGINATION_DEFAULT_LIMIT,
+};
 use crate::search::parse_filter;
+use crate::Opt;
 
 static ACCEPTED_CONTENT_TYPE: Lazy<Vec<String>> = Lazy::new(|| {
     vec!["application/json".to_string(), "application/x-ndjson".to_string(), "text/csv".to_string()]
@@ -119,6 +122,7 @@ pub async fn delete_document(
     index_scheduler: GuardedData<ActionPolicy<{ actions::DOCUMENTS_DELETE }>, Data<IndexScheduler>>,
     path: web::Path<DocumentParam>,
     req: HttpRequest,
+    opt: web::Data<Opt>,
     analytics: web::Data<dyn Analytics>,
 ) -> Result<HttpResponse, ResponseError> {
     let DocumentParam { index_uid, document_id } = path.into_inner();
@@ -130,9 +134,13 @@ pub async fn delete_document(
         index_uid: index_uid.to_string(),
         documents_ids: vec![document_id],
     };
+    let uid = get_task_id(&req, &opt)?;
+    let dry_run = is_dry_run(&req, &opt)?;
     let task: SummarizedTaskView =
-        tokio::task::spawn_blocking(move || index_scheduler.register(task)).await??.into();
+        tokio::task::spawn_blocking(move || index_scheduler.register(task, uid, dry_run))
-    debug!(returns = ?task, "Delete document");
+            .await??
+            .into();
+    debug!("returns: {:?}", task);
     Ok(HttpResponse::Accepted().json(task))
 }
 
@@ -267,6 +275,7 @@ pub async fn replace_documents(
     params: AwebQueryParameter<UpdateDocumentsQuery, DeserrQueryParamError>,
     body: Payload,
     req: HttpRequest,
+    opt: web::Data<Opt>,
     analytics: web::Data<dyn Analytics>,
 ) -> Result<HttpResponse, ResponseError> {
     let index_uid = IndexUid::try_from(index_uid.into_inner())?;
@@ -277,6 +286,8 @@ pub async fn replace_documents(
     analytics.add_documents(&params, index_scheduler.index(&index_uid).is_err(), &req);
 
     let allow_index_creation = index_scheduler.filters().allow_index_creation(&index_uid);
+    let uid = get_task_id(&req, &opt)?;
+    let dry_run = is_dry_run(&req, &opt)?;
     let task = document_addition(
         extract_mime_type(&req)?,
         index_scheduler,
@@ -285,6 +296,8 @@ pub async fn replace_documents(
         params.csv_delimiter,
         body,
         IndexDocumentsMethod::ReplaceDocuments,
+        uid,
+        dry_run,
         allow_index_creation,
     )
     .await?;
@@ -299,6 +312,7 @@ pub async fn update_documents(
     params: AwebQueryParameter<UpdateDocumentsQuery, DeserrQueryParamError>,
     body: Payload,
     req: HttpRequest,
+    opt: web::Data<Opt>,
     analytics: web::Data<dyn Analytics>,
 ) -> Result<HttpResponse, ResponseError> {
     let index_uid = IndexUid::try_from(index_uid.into_inner())?;
@@ -309,6 +323,8 @@ pub async fn update_documents(
     analytics.update_documents(&params, index_scheduler.index(&index_uid).is_err(), &req);
 
     let allow_index_creation = index_scheduler.filters().allow_index_creation(&index_uid);
+    let uid = get_task_id(&req, &opt)?;
+    let dry_run = is_dry_run(&req, &opt)?;
     let task = document_addition(
         extract_mime_type(&req)?,
         index_scheduler,
@@ -317,6 +333,8 @@ pub async fn update_documents(
         params.csv_delimiter,
         body,
         IndexDocumentsMethod::UpdateDocuments,
+        uid,
+        dry_run,
         allow_index_creation,
     )
     .await?;
@@ -334,6 +352,8 @@ async fn document_addition(
     csv_delimiter: Option<u8>,
     mut body: Payload,
     method: IndexDocumentsMethod,
+    task_id: Option<TaskId>,
+    dry_run: bool,
     allow_index_creation: bool,
 ) -> Result<SummarizedTaskView, MeilisearchHttpError> {
     let format = match (
@@ -366,7 +386,7 @@ async fn document_addition(
         }
     };
 
-    let (uuid, mut update_file) = index_scheduler.create_update_file()?;
+    let (uuid, mut update_file) = index_scheduler.create_update_file(dry_run)?;
 
     let temp_file = match tempfile() {
         Ok(file) => file,
@@ -405,11 +425,9 @@ async fn document_addition(
     let read_file = buffer.into_inner().into_std().await;
     let documents_count = tokio::task::spawn_blocking(move || {
         let documents_count = match format {
-            PayloadType::Json => read_json(&read_file, update_file.as_file_mut())?,
+            PayloadType::Json => read_json(&read_file, &mut update_file)?,
-            PayloadType::Csv { delimiter } => {
+            PayloadType::Csv { delimiter } => read_csv(&read_file, &mut update_file, delimiter)?,
-                read_csv(&read_file, update_file.as_file_mut(), delimiter)?
+            PayloadType::Ndjson => read_ndjson(&read_file, &mut update_file)?,
-            }
-            PayloadType::Ndjson => read_ndjson(&read_file, update_file.as_file_mut())?,
         };
         // we NEED to persist the file here because we moved the `udpate_file` in another task.
         update_file.persist()?;
@@ -450,7 +468,9 @@ async fn document_addition(
     };
 
     let scheduler = index_scheduler.clone();
-    let task = match tokio::task::spawn_blocking(move || scheduler.register(task)).await? {
+    let task = match tokio::task::spawn_blocking(move || scheduler.register(task, task_id, dry_run))
+        .await?
+    {
         Ok(task) => task,
         Err(e) => {
             index_scheduler.delete_update_file(uuid)?;
@@ -466,6 +486,7 @@ pub async fn delete_documents_batch(
     index_uid: web::Path<String>,
     body: web::Json<Vec<Value>>,
     req: HttpRequest,
+    opt: web::Data<Opt>,
     analytics: web::Data<dyn Analytics>,
 ) -> Result<HttpResponse, ResponseError> {
     debug!(parameters = ?body, "Delete documents by batch");
@@ -480,8 +501,12 @@ pub async fn delete_documents_batch(
 
     let task =
         KindWithContent::DocumentDeletion { index_uid: index_uid.to_string(), documents_ids: ids };
+    let uid = get_task_id(&req, &opt)?;
+    let dry_run = is_dry_run(&req, &opt)?;
     let task: SummarizedTaskView =
-        tokio::task::spawn_blocking(move || index_scheduler.register(task)).await??.into();
+        tokio::task::spawn_blocking(move || index_scheduler.register(task, uid, dry_run))
+            .await??
+            .into();
 
     debug!(returns = ?task, "Delete documents by batch");
     Ok(HttpResponse::Accepted().json(task))
@@ -499,6 +524,7 @@ pub async fn delete_documents_by_filter(
     index_uid: web::Path<String>,
     body: AwebJson<DocumentDeletionByFilter, DeserrJsonError>,
     req: HttpRequest,
+    opt: web::Data<Opt>,
     analytics: web::Data<dyn Analytics>,
 ) -> Result<HttpResponse, ResponseError> {
     debug!(parameters = ?body, "Delete documents by filter");
@@ -516,8 +542,12 @@ pub async fn delete_documents_by_filter(
     .map_err(|err| ResponseError::from_msg(err.message, Code::InvalidDocumentFilter))?;
     let task = KindWithContent::DocumentDeletionByFilter { index_uid, filter_expr: filter };
 
+    let uid = get_task_id(&req, &opt)?;
+    let dry_run = is_dry_run(&req, &opt)?;
     let task: SummarizedTaskView =
-        tokio::task::spawn_blocking(move || index_scheduler.register(task)).await??.into();
+        tokio::task::spawn_blocking(move || index_scheduler.register(task, uid, dry_run))
+            .await??
+            .into();
 
     debug!(returns = ?task, "Delete documents by filter");
     Ok(HttpResponse::Accepted().json(task))
@@ -527,14 +557,19 @@ pub async fn clear_all_documents(
     index_scheduler: GuardedData<ActionPolicy<{ actions::DOCUMENTS_DELETE }>, Data<IndexScheduler>>,
     index_uid: web::Path<String>,
     req: HttpRequest,
+    opt: web::Data<Opt>,
     analytics: web::Data<dyn Analytics>,
 ) -> Result<HttpResponse, ResponseError> {
     let index_uid = IndexUid::try_from(index_uid.into_inner())?;
     analytics.delete_documents(DocumentDeletionKind::ClearAll, &req);
 
     let task = KindWithContent::DocumentClear { index_uid: index_uid.to_string() };
+    let uid = get_task_id(&req, &opt)?;
+    let dry_run = is_dry_run(&req, &opt)?;
     let task: SummarizedTaskView =
-        tokio::task::spawn_blocking(move || index_scheduler.register(task)).await??.into();
+        tokio::task::spawn_blocking(move || index_scheduler.register(task, uid, dry_run))
+            .await??
+            .into();
 
     debug!(returns = ?task, "Delete all documents");
     Ok(HttpResponse::Accepted().json(task))

meilisearch/src/routes/indexes/mod.rs

@@ -17,11 +17,13 @@ use serde_json::json;
 use time::OffsetDateTime;
 use tracing::debug;
 
-use super::{Pagination, SummarizedTaskView, PAGINATION_DEFAULT_LIMIT};
+use super::{get_task_id, Pagination, SummarizedTaskView, PAGINATION_DEFAULT_LIMIT};
 use crate::analytics::Analytics;
 use crate::extractors::authentication::policies::*;
 use crate::extractors::authentication::{AuthenticationError, GuardedData};
 use crate::extractors::sequential_extractor::SeqHandler;
+use crate::routes::is_dry_run;
+use crate::Opt;
 
 pub mod documents;
 pub mod facet_search;
@@ -123,6 +125,7 @@ pub async fn create_index(
     index_scheduler: GuardedData<ActionPolicy<{ actions::INDEXES_CREATE }>, Data<IndexScheduler>>,
     body: AwebJson<IndexCreateRequest, DeserrJsonError>,
     req: HttpRequest,
+    opt: web::Data<Opt>,
     analytics: web::Data<dyn Analytics>,
 ) -> Result<HttpResponse, ResponseError> {
     debug!(parameters = ?body, "Create index");
@@ -137,8 +140,12 @@ pub async fn create_index(
         );
 
         let task = KindWithContent::IndexCreation { index_uid: uid.to_string(), primary_key };
+        let uid = get_task_id(&req, &opt)?;
+        let dry_run = is_dry_run(&req, &opt)?;
         let task: SummarizedTaskView =
-            tokio::task::spawn_blocking(move || index_scheduler.register(task)).await??.into();
+            tokio::task::spawn_blocking(move || index_scheduler.register(task, uid, dry_run))
+                .await??
+                .into();
         debug!(returns = ?task, "Create index");
 
         Ok(HttpResponse::Accepted().json(task))
@@ -190,6 +197,7 @@ pub async fn update_index(
     index_uid: web::Path<String>,
     body: AwebJson<UpdateIndexRequest, DeserrJsonError>,
     req: HttpRequest,
+    opt: web::Data<Opt>,
     analytics: web::Data<dyn Analytics>,
 ) -> Result<HttpResponse, ResponseError> {
     debug!(parameters = ?body, "Update index");
@@ -206,8 +214,12 @@ pub async fn update_index(
         primary_key: body.primary_key,
     };
 
+    let uid = get_task_id(&req, &opt)?;
+    let dry_run = is_dry_run(&req, &opt)?;
     let task: SummarizedTaskView =
-        tokio::task::spawn_blocking(move || index_scheduler.register(task)).await??.into();
+        tokio::task::spawn_blocking(move || index_scheduler.register(task, uid, dry_run))
+            .await??
+            .into();
 
     debug!(returns = ?task, "Update index");
     Ok(HttpResponse::Accepted().json(task))
@@ -216,11 +228,17 @@ pub async fn update_index(
 pub async fn delete_index(
     index_scheduler: GuardedData<ActionPolicy<{ actions::INDEXES_DELETE }>, Data<IndexScheduler>>,
     index_uid: web::Path<String>,
+    req: HttpRequest,
+    opt: web::Data<Opt>,
 ) -> Result<HttpResponse, ResponseError> {
     let index_uid = IndexUid::try_from(index_uid.into_inner())?;
     let task = KindWithContent::IndexDeletion { index_uid: index_uid.into_inner() };
+    let uid = get_task_id(&req, &opt)?;
+    let dry_run = is_dry_run(&req, &opt)?;
     let task: SummarizedTaskView =
-        tokio::task::spawn_blocking(move || index_scheduler.register(task)).await??.into();
+        tokio::task::spawn_blocking(move || index_scheduler.register(task, uid, dry_run))
+            .await??
+            .into();
     debug!(returns = ?task, "Delete index");
 
     Ok(HttpResponse::Accepted().json(task))

meilisearch/src/routes/indexes/settings.rs

@@ -15,7 +15,8 @@ use tracing::debug;
 use crate::analytics::Analytics;
 use crate::extractors::authentication::policies::*;
 use crate::extractors::authentication::GuardedData;
-use crate::routes::SummarizedTaskView;
+use crate::routes::{get_task_id, is_dry_run, SummarizedTaskView};
+use crate::Opt;
 
 #[macro_export]
 macro_rules! make_setting_route {
@@ -34,7 +35,8 @@ macro_rules! make_setting_route {
             use $crate::extractors::authentication::policies::*;
             use $crate::extractors::authentication::GuardedData;
             use $crate::extractors::sequential_extractor::SeqHandler;
-            use $crate::routes::SummarizedTaskView;
+            use $crate::Opt;
+            use $crate::routes::{is_dry_run, get_task_id, SummarizedTaskView};
 
             pub async fn delete(
                 index_scheduler: GuardedData<
@@ -42,6 +44,8 @@ macro_rules! make_setting_route {
                     Data<IndexScheduler>,
                 >,
                 index_uid: web::Path<String>,
+                req: HttpRequest,
+                opt: web::Data<Opt>,
             ) -> Result<HttpResponse, ResponseError> {
                 let index_uid = IndexUid::try_from(index_uid.into_inner())?;
 
@@ -56,8 +60,10 @@ macro_rules! make_setting_route {
                     is_deletion: true,
                     allow_index_creation,
                 };
+                let uid = get_task_id(&req, &opt)?;
+                let dry_run = is_dry_run(&req, &opt)?;
                 let task: SummarizedTaskView =
-                    tokio::task::spawn_blocking(move || index_scheduler.register(task))
+                    tokio::task::spawn_blocking(move || index_scheduler.register(task, uid, dry_run))
                         .await??
                         .into();
 
@@ -73,6 +79,7 @@ macro_rules! make_setting_route {
                 index_uid: actix_web::web::Path<String>,
                 body: deserr::actix_web::AwebJson<Option<$type>, $err_ty>,
                 req: HttpRequest,
+                opt: web::Data<Opt>,
                 $analytics_var: web::Data<dyn Analytics>,
             ) -> std::result::Result<HttpResponse, ResponseError> {
                 let index_uid = IndexUid::try_from(index_uid.into_inner())?;
@@ -105,8 +112,10 @@ macro_rules! make_setting_route {
                     is_deletion: false,
                     allow_index_creation,
                 };
+                let uid = get_task_id(&req, &opt)?;
+                let dry_run = is_dry_run(&req, &opt)?;
                 let task: SummarizedTaskView =
-                    tokio::task::spawn_blocking(move || index_scheduler.register(task))
+                    tokio::task::spawn_blocking(move || index_scheduler.register(task, uid, dry_run))
                         .await??
                         .into();
 
@@ -652,6 +661,7 @@ pub async fn update_all(
     index_uid: web::Path<String>,
     body: AwebJson<Settings<Unchecked>, DeserrJsonError>,
     req: HttpRequest,
+    opt: web::Data<Opt>,
     analytics: web::Data<dyn Analytics>,
 ) -> Result<HttpResponse, ResponseError> {
     let index_uid = IndexUid::try_from(index_uid.into_inner())?;
@@ -767,8 +777,12 @@ pub async fn update_all(
         is_deletion: false,
         allow_index_creation,
     };
+    let uid = get_task_id(&req, &opt)?;
+    let dry_run = is_dry_run(&req, &opt)?;
     let task: SummarizedTaskView =
-        tokio::task::spawn_blocking(move || index_scheduler.register(task)).await??.into();
+        tokio::task::spawn_blocking(move || index_scheduler.register(task, uid, dry_run))
+            .await??
+            .into();
 
     debug!(returns = ?task, "Update all settings");
     Ok(HttpResponse::Accepted().json(task))
@@ -790,6 +804,8 @@ pub async fn get_all(
 pub async fn delete_all(
     index_scheduler: GuardedData<ActionPolicy<{ actions::SETTINGS_UPDATE }>, Data<IndexScheduler>>,
     index_uid: web::Path<String>,
+    req: HttpRequest,
+    opt: web::Data<Opt>,
 ) -> Result<HttpResponse, ResponseError> {
     let index_uid = IndexUid::try_from(index_uid.into_inner())?;
 
@@ -803,8 +819,12 @@ pub async fn delete_all(
         is_deletion: true,
         allow_index_creation,
     };
+    let uid = get_task_id(&req, &opt)?;
+    let dry_run = is_dry_run(&req, &opt)?;
     let task: SummarizedTaskView =
-        tokio::task::spawn_blocking(move || index_scheduler.register(task)).await??.into();
+        tokio::task::spawn_blocking(move || index_scheduler.register(task, uid, dry_run))
+            .await??
+            .into();
 
     debug!(returns = ?task, "Delete all settings");
     Ok(HttpResponse::Accepted().json(task))

meilisearch/src/routes/mod.rs

@@ -4,7 +4,7 @@ use actix_web::web::Data;
 use actix_web::{web, HttpRequest, HttpResponse};
 use index_scheduler::IndexScheduler;
 use meilisearch_auth::AuthController;
-use meilisearch_types::error::ResponseError;
+use meilisearch_types::error::{Code, ResponseError};
 use meilisearch_types::settings::{Settings, Unchecked};
 use meilisearch_types::tasks::{Kind, Status, Task, TaskId};
 use serde::{Deserialize, Serialize};
@@ -15,6 +15,7 @@ use tracing::debug;
 use crate::analytics::Analytics;
 use crate::extractors::authentication::policies::*;
 use crate::extractors::authentication::GuardedData;
+use crate::Opt;
 
 const PAGINATION_DEFAULT_LIMIT: usize = 20;
 
@@ -45,6 +46,56 @@ pub fn configure(cfg: &mut web::ServiceConfig) {
         .service(web::scope("/experimental-features").configure(features::configure));
 }
 
+pub fn get_task_id(req: &HttpRequest, opt: &Opt) -> Result<Option<TaskId>, ResponseError> {
+    if !opt.experimental_replication_parameters {
+        return Ok(None);
+    }
+    let task_id = req
+        .headers()
+        .get("TaskId")
+        .map(|header| {
+            header.to_str().map_err(|e| {
+                ResponseError::from_msg(
+                    format!("TaskId is not a valid utf-8 string: {e}"),
+                    Code::BadRequest,
+                )
+            })
+        })
+        .transpose()?
+        .map(|s| {
+            s.parse::<TaskId>().map_err(|e| {
+                ResponseError::from_msg(
+                    format!(
+                        "Could not parse the TaskId as a {}: {e}",
+                        std::any::type_name::<TaskId>(),
+                    ),
+                    Code::BadRequest,
+                )
+            })
+        })
+        .transpose()?;
+    Ok(task_id)
+}
+
+pub fn is_dry_run(req: &HttpRequest, opt: &Opt) -> Result<bool, ResponseError> {
+    if !opt.experimental_replication_parameters {
+        return Ok(false);
+    }
+    Ok(req
+        .headers()
+        .get("DryRun")
+        .map(|header| {
+            header.to_str().map_err(|e| {
+                ResponseError::from_msg(
+                    format!("DryRun is not a valid utf-8 string: {e}"),
+                    Code::BadRequest,
+                )
+            })
+        })
+        .transpose()?
+        .map_or(false, |s| s.to_lowercase() == "true"))
+}
+
 #[derive(Debug, Serialize)]
 #[serde(rename_all = "camelCase")]
 pub struct SummarizedTaskView {

meilisearch/src/routes/snapshot.rs

@@ -10,7 +10,8 @@ use crate::analytics::Analytics;
 use crate::extractors::authentication::policies::*;
 use crate::extractors::authentication::GuardedData;
 use crate::extractors::sequential_extractor::SeqHandler;
-use crate::routes::SummarizedTaskView;
+use crate::routes::{get_task_id, is_dry_run, SummarizedTaskView};
+use crate::Opt;
 
 pub fn configure(cfg: &mut web::ServiceConfig) {
     cfg.service(web::resource("").route(web::post().to(SeqHandler(create_snapshot))));
@@ -19,13 +20,18 @@ pub fn configure(cfg: &mut web::ServiceConfig) {
 pub async fn create_snapshot(
     index_scheduler: GuardedData<ActionPolicy<{ actions::SNAPSHOTS_CREATE }>, Data<IndexScheduler>>,
     req: HttpRequest,
+    opt: web::Data<Opt>,
     analytics: web::Data<dyn Analytics>,
 ) -> Result<HttpResponse, ResponseError> {
     analytics.publish("Snapshot Created".to_string(), json!({}), Some(&req));
 
     let task = KindWithContent::SnapshotCreation;
+    let uid = get_task_id(&req, &opt)?;
+    let dry_run = is_dry_run(&req, &opt)?;
     let task: SummarizedTaskView =
-        tokio::task::spawn_blocking(move || index_scheduler.register(task)).await??.into();
+        tokio::task::spawn_blocking(move || index_scheduler.register(task, uid, dry_run))
+            .await??
+            .into();
 
     debug!(returns = ?task, "Create snapshot");
     Ok(HttpResponse::Accepted().json(task))

meilisearch/src/routes/swap_indexes.rs

@@ -10,12 +10,13 @@ use meilisearch_types::index_uid::IndexUid;
 use meilisearch_types::tasks::{IndexSwap, KindWithContent};
 use serde_json::json;
 
-use super::SummarizedTaskView;
+use super::{get_task_id, is_dry_run, SummarizedTaskView};
 use crate::analytics::Analytics;
 use crate::error::MeilisearchHttpError;
 use crate::extractors::authentication::policies::*;
 use crate::extractors::authentication::{AuthenticationError, GuardedData};
 use crate::extractors::sequential_extractor::SeqHandler;
+use crate::Opt;
 
 pub fn configure(cfg: &mut web::ServiceConfig) {
     cfg.service(web::resource("").route(web::post().to(SeqHandler(swap_indexes))));
@@ -32,6 +33,7 @@ pub async fn swap_indexes(
     index_scheduler: GuardedData<ActionPolicy<{ actions::INDEXES_SWAP }>, Data<IndexScheduler>>,
     params: AwebJson<Vec<SwapIndexesPayload>, DeserrJsonError>,
     req: HttpRequest,
+    opt: web::Data<Opt>,
     analytics: web::Data<dyn Analytics>,
 ) -> Result<HttpResponse, ResponseError> {
     let params = params.into_inner();
@@ -60,7 +62,11 @@ pub async fn swap_indexes(
     }
 
     let task = KindWithContent::IndexSwap { swaps };
+    let uid = get_task_id(&req, &opt)?;
+    let dry_run = is_dry_run(&req, &opt)?;
     let task: SummarizedTaskView =
-        tokio::task::spawn_blocking(move || index_scheduler.register(task)).await??.into();
+        tokio::task::spawn_blocking(move || index_scheduler.register(task, uid, dry_run))
+            .await??
+            .into();
     Ok(HttpResponse::Accepted().json(task))
 }

meilisearch/src/routes/tasks.rs

@@ -18,11 +18,12 @@ use time::macros::format_description;
 use time::{Date, Duration, OffsetDateTime, Time};
 use tokio::task;
 
-use super::SummarizedTaskView;
+use super::{get_task_id, is_dry_run, SummarizedTaskView};
 use crate::analytics::Analytics;
 use crate::extractors::authentication::policies::*;
 use crate::extractors::authentication::GuardedData;
 use crate::extractors::sequential_extractor::SeqHandler;
+use crate::Opt;
 
 const DEFAULT_LIMIT: u32 = 20;
 
@@ -161,6 +162,7 @@ async fn cancel_tasks(
     index_scheduler: GuardedData<ActionPolicy<{ actions::TASKS_CANCEL }>, Data<IndexScheduler>>,
     params: AwebQueryParameter<TaskDeletionOrCancelationQuery, DeserrQueryParamError>,
     req: HttpRequest,
+    opt: web::Data<Opt>,
     analytics: web::Data<dyn Analytics>,
 ) -> Result<HttpResponse, ResponseError> {
     let params = params.into_inner();
@@ -197,7 +199,11 @@ async fn cancel_tasks(
     let task_cancelation =
         KindWithContent::TaskCancelation { query: format!("?{}", req.query_string()), tasks };
 
-    let task = task::spawn_blocking(move || index_scheduler.register(task_cancelation)).await??;
+    let uid = get_task_id(&req, &opt)?;
+    let dry_run = is_dry_run(&req, &opt)?;
+    let task =
+        task::spawn_blocking(move || index_scheduler.register(task_cancelation, uid, dry_run))
+            .await??;
     let task: SummarizedTaskView = task.into();
 
     Ok(HttpResponse::Ok().json(task))
@@ -207,6 +213,7 @@ async fn delete_tasks(
     index_scheduler: GuardedData<ActionPolicy<{ actions::TASKS_DELETE }>, Data<IndexScheduler>>,
     params: AwebQueryParameter<TaskDeletionOrCancelationQuery, DeserrQueryParamError>,
     req: HttpRequest,
+    opt: web::Data<Opt>,
     analytics: web::Data<dyn Analytics>,
 ) -> Result<HttpResponse, ResponseError> {
     let params = params.into_inner();
@@ -242,7 +249,10 @@ async fn delete_tasks(
     let task_deletion =
         KindWithContent::TaskDeletion { query: format!("?{}", req.query_string()), tasks };
 
-    let task = task::spawn_blocking(move || index_scheduler.register(task_deletion)).await??;
+    let uid = get_task_id(&req, &opt)?;
+    let dry_run = is_dry_run(&req, &opt)?;
+    let task = task::spawn_blocking(move || index_scheduler.register(task_deletion, uid, dry_run))
+        .await??;
     let task: SummarizedTaskView = task.into();
 
     Ok(HttpResponse::Ok().json(task))

meilisearch/tests/common/index.rs

@@ -100,16 +100,11 @@ impl Index<'_> {
     pub async fn raw_add_documents(
         &self,
         payload: &str,
-        content_type: Option<&str>,
+        headers: Vec<(&str, &str)>,
         query_parameter: &str,
     ) -> (Value, StatusCode) {
         let url = format!("/indexes/{}/documents{}", urlencode(self.uid.as_ref()), query_parameter);
-
+        self.service.post_str(url, payload, headers).await
-        if let Some(content_type) = content_type {
-            self.service.post_str(url, payload, vec![("Content-Type", content_type)]).await
-        } else {
-            self.service.post_str(url, payload, Vec::new()).await
-        }
     }
 
     pub async fn update_documents(

meilisearch/tests/documents/add_documents.rs

@@ -1,10 +1,11 @@
 use actix_web::test;
 use meili_snap::{json_string, snapshot};
+use meilisearch::Opt;
 use time::format_description::well_known::Rfc3339;
 use time::OffsetDateTime;
 
 use crate::common::encoder::Encoder;
-use crate::common::{GetAllDocumentsOptions, Server, Value};
+use crate::common::{default_settings, GetAllDocumentsOptions, Server, Value};
 use crate::json;
 
 /// This is the basic usage of our API and every other tests uses the content-type application/json
@@ -2157,3 +2158,49 @@ async fn batch_several_documents_addition() {
     assert_eq!(code, 200, "failed with `{}`", response);
     assert_eq!(response["results"].as_array().unwrap().len(), 120);
 }
+
+#[actix_rt::test]
+async fn dry_register_file() {
+    let temp = tempfile::tempdir().unwrap();
+
+    let options =
+        Opt { experimental_replication_parameters: true, ..default_settings(temp.path()) };
+    let server = Server::new_with_options(options).await.unwrap();
+    let index = server.index("tamo");
+
+    let documents = r#"
+        {
+            "id": "12",
+            "doggo": "kefir"
+        }
+    "#;
+
+    let (response, code) = index
+        .raw_add_documents(
+            documents,
+            vec![("Content-Type", "application/json"), ("DryRun", "true")],
+            "",
+        )
+        .await;
+    snapshot!(response, @r###"
+    {
+      "taskUid": 0,
+      "indexUid": "tamo",
+      "status": "enqueued",
+      "type": "documentAdditionOrUpdate",
+      "enqueuedAt": "[date]"
+    }
+    "###);
+    snapshot!(code, @"202 Accepted");
+
+    let (response, code) = index.get_task(response.uid()).await;
+    snapshot!(response, @r###"
+    {
+      "message": "Task `0` not found.",
+      "code": "task_not_found",
+      "type": "invalid_request",
+      "link": "https://docs.meilisearch.com/errors#task_not_found"
+    }
+    "###);
+    snapshot!(code, @"404 Not Found");
+}

meilisearch/tests/documents/errors.rs

@@ -209,7 +209,8 @@ async fn replace_documents_missing_payload() {
     let server = Server::new().await;
     let index = server.index("test");
 
-    let (response, code) = index.raw_add_documents("", Some("application/json"), "").await;
+    let (response, code) =
+        index.raw_add_documents("", vec![("Content-Type", "application/json")], "").await;
     snapshot!(code, @"400 Bad Request");
     snapshot!(json_string!(response), @r###"
     {
@@ -220,7 +221,8 @@ async fn replace_documents_missing_payload() {
     }
     "###);
 
-    let (response, code) = index.raw_add_documents("", Some("application/x-ndjson"), "").await;
+    let (response, code) =
+        index.raw_add_documents("", vec![("Content-Type", "application/x-ndjson")], "").await;
     snapshot!(code, @"400 Bad Request");
     snapshot!(json_string!(response), @r###"
     {
@@ -231,7 +233,8 @@ async fn replace_documents_missing_payload() {
     }
     "###);
 
-    let (response, code) = index.raw_add_documents("", Some("text/csv"), "").await;
+    let (response, code) =
+        index.raw_add_documents("", vec![("Content-Type", "text/csv")], "").await;
     snapshot!(code, @"400 Bad Request");
     snapshot!(json_string!(response), @r###"
     {
@@ -287,7 +290,7 @@ async fn replace_documents_missing_content_type() {
     let server = Server::new().await;
     let index = server.index("test");
 
-    let (response, code) = index.raw_add_documents("", None, "").await;
+    let (response, code) = index.raw_add_documents("", Vec::new(), "").await;
     snapshot!(code, @"415 Unsupported Media Type");
     snapshot!(json_string!(response), @r###"
     {
@@ -299,7 +302,7 @@ async fn replace_documents_missing_content_type() {
     "###);
 
     // even with a csv delimiter specified this error is triggered first
-    let (response, code) = index.raw_add_documents("", None, "?csvDelimiter=;").await;
+    let (response, code) = index.raw_add_documents("", Vec::new(), "?csvDelimiter=;").await;
     snapshot!(code, @"415 Unsupported Media Type");
     snapshot!(json_string!(response), @r###"
     {
@@ -345,7 +348,7 @@ async fn replace_documents_bad_content_type() {
     let server = Server::new().await;
     let index = server.index("test");
 
-    let (response, code) = index.raw_add_documents("", Some("doggo"), "").await;
+    let (response, code) = index.raw_add_documents("", vec![("Content-Type", "doggo")], "").await;
     snapshot!(code, @"415 Unsupported Media Type");
     snapshot!(json_string!(response), @r###"
     {
@@ -379,8 +382,9 @@ async fn replace_documents_bad_csv_delimiter() {
     let server = Server::new().await;
     let index = server.index("test");
 
-    let (response, code) =
+    let (response, code) = index
-        index.raw_add_documents("", Some("application/json"), "?csvDelimiter").await;
+        .raw_add_documents("", vec![("Content-Type", "application/json")], "?csvDelimiter")
+        .await;
     snapshot!(code, @"400 Bad Request");
     snapshot!(json_string!(response), @r###"
     {
@@ -391,8 +395,9 @@ async fn replace_documents_bad_csv_delimiter() {
     }
     "###);
 
-    let (response, code) =
+    let (response, code) = index
-        index.raw_add_documents("", Some("application/json"), "?csvDelimiter=doggo").await;
+        .raw_add_documents("", vec![("Content-Type", "application/json")], "?csvDelimiter=doggo")
+        .await;
     snapshot!(code, @"400 Bad Request");
     snapshot!(json_string!(response), @r###"
     {
@@ -404,7 +409,11 @@ async fn replace_documents_bad_csv_delimiter() {
     "###);
 
     let (response, code) = index
-        .raw_add_documents("", Some("application/json"), &format!("?csvDelimiter={}", encode("🍰")))
+        .raw_add_documents(
+            "",
+            vec![("Content-Type", "application/json")],
+            &format!("?csvDelimiter={}", encode("🍰")),
+        )
         .await;
     snapshot!(code, @"400 Bad Request");
     snapshot!(json_string!(response), @r###"
@@ -469,8 +478,9 @@ async fn replace_documents_csv_delimiter_with_bad_content_type() {
     let server = Server::new().await;
     let index = server.index("test");
 
-    let (response, code) =
+    let (response, code) = index
-        index.raw_add_documents("", Some("application/json"), "?csvDelimiter=a").await;
+        .raw_add_documents("", vec![("Content-Type", "application/json")], "?csvDelimiter=a")
+        .await;
     snapshot!(code, @"415 Unsupported Media Type");
     snapshot!(json_string!(response), @r###"
     {
@@ -481,8 +491,9 @@ async fn replace_documents_csv_delimiter_with_bad_content_type() {
     }
     "###);
 
-    let (response, code) =
+    let (response, code) = index
-        index.raw_add_documents("", Some("application/x-ndjson"), "?csvDelimiter=a").await;
+        .raw_add_documents("", vec![("Content-Type", "application/x-ndjson")], "?csvDelimiter=a")
+        .await;
     snapshot!(code, @"415 Unsupported Media Type");
     snapshot!(json_string!(response), @r###"
     {

meilisearch/tests/index/create_index.rs

@@ -2,9 +2,10 @@ use actix_web::http::header::ContentType;
 use actix_web::test;
 use http::header::ACCEPT_ENCODING;
 use meili_snap::{json_string, snapshot};
+use meilisearch::Opt;
 
 use crate::common::encoder::Encoder;
-use crate::common::{Server, Value};
+use crate::common::{default_settings, Server, Value};
 use crate::json;
 
 #[actix_rt::test]
@@ -199,3 +200,79 @@ async fn error_create_with_invalid_index_uid() {
     }
     "###);
 }
+
+#[actix_rt::test]
+async fn send_task_id() {
+    let temp = tempfile::tempdir().unwrap();
+
+    let options =
+        Opt { experimental_replication_parameters: true, ..default_settings(temp.path()) };
+    let server = Server::new_with_options(options).await.unwrap();
+
+    let app = server.init_web_app().await;
+    let index = server.index("catto");
+    let (response, code) = index.create(None).await;
+    snapshot!(code, @"202 Accepted");
+    snapshot!(json_string!(response, { ".enqueuedAt" => "[date]" }), @r###"
+    {
+      "taskUid": 0,
+      "indexUid": "catto",
+      "status": "enqueued",
+      "type": "indexCreation",
+      "enqueuedAt": "[date]"
+    }
+    "###);
+
+    let body = serde_json::to_string(&json!({
+        "uid": "doggo",
+        "primaryKey": None::<&str>,
+    }))
+    .unwrap();
+    let req = test::TestRequest::post()
+        .uri("/indexes")
+        .insert_header(("TaskId", "25"))
+        .insert_header(ContentType::json())
+        .set_payload(body)
+        .to_request();
+
+    let res = test::call_service(&app, req).await;
+    snapshot!(res.status(), @"202 Accepted");
+
+    let bytes = test::read_body(res).await;
+    let response = serde_json::from_slice::<Value>(&bytes).expect("Expecting valid json");
+    snapshot!(json_string!(response, { ".enqueuedAt" => "[date]" }), @r###"
+    {
+      "taskUid": 25,
+      "indexUid": "doggo",
+      "status": "enqueued",
+      "type": "indexCreation",
+      "enqueuedAt": "[date]"
+    }
+    "###);
+
+    let body = serde_json::to_string(&json!({
+        "uid": "girafo",
+        "primaryKey": None::<&str>,
+    }))
+    .unwrap();
+    let req = test::TestRequest::post()
+        .uri("/indexes")
+        .insert_header(("TaskId", "12"))
+        .insert_header(ContentType::json())
+        .set_payload(body)
+        .to_request();
+
+    let res = test::call_service(&app, req).await;
+    snapshot!(res.status(), @"400 Bad Request");
+
+    let bytes = test::read_body(res).await;
+    let response = serde_json::from_slice::<Value>(&bytes).expect("Expecting valid json");
+    snapshot!(json_string!(response), @r###"
+    {
+      "message": "Received bad task id: 12 should be >= to 26.",
+      "code": "bad_request",
+      "type": "invalid_request",
+      "link": "https://docs.meilisearch.com/errors#bad_request"
+    }
+    "###);
+}