MeiliSearch/index-scheduler/src
bors[bot] b08a49a16e
Merge #3319 #3470
3319: Transparently resize indexes on MaxDatabaseSizeReached errors r=Kerollmops a=dureuill

# Pull Request

## Related issue
Related to https://github.com/meilisearch/meilisearch/discussions/3280, depends on https://github.com/meilisearch/milli/pull/760

## What does this PR do?

### User standpoint

- Meilisearch no longer fails tasks that encounter the `milli::UserError(MaxDatabaseSizeReached)` error.
- Instead, these tasks are retried after increasing the maximum size allocated to the index where the failure occurred.

### Implementation standpoint

- Add `Batch::index_uid` to get the `index_uid` of a batch of task if there is one
- `IndexMapper::create_or_open_index` now takes an additional `size` argument that allows to (re)open indexes with a size different from the base `IndexScheduler::index_size` field
- `IndexScheduler::tick` now returns a `Result<TickOutcome>` instead of a `Result<usize>`. This offers more explicit control over what the behavior should be wrt the next tick.
- Add `IndexStatus::BeingResized` that contains a handle that a thread can use to await for the resize operation to complete and the index to be available again.
- Add `IndexMapper::resize_index` to increase the size of an index.
- In `IndexScheduler::tick`, intercept task batches that failed due to `MaxDatabaseSizeReached` and resize the index that caused the error, then request a new tick that will eventually handle the still enqueued task.

## Testing the PR

The following diff can be applied to this branch to make testing the PR easier:

<details>


```diff
diff --git a/index-scheduler/src/index_mapper.rs b/index-scheduler/src/index_mapper.rs
index 553ab45a..022b2f00 100644
--- a/index-scheduler/src/index_mapper.rs
+++ b/index-scheduler/src/index_mapper.rs
`@@` -228,13 +228,15 `@@` impl IndexMapper {
 
         drop(lock);
 
+        std:🧵:sleep_ms(2000);
+
         let current_size = index.map_size()?;
         let closing_event = index.prepare_for_closing();
-        log::info!("Resizing index {} from {} to {} bytes", name, current_size, current_size * 2);
+        log::error!("Resizing index {} from {} to {} bytes", name, current_size, current_size * 2);
 
         closing_event.wait();
 
-        log::info!("Resized index {} from {} to {} bytes", name, current_size, current_size * 2);
+        log::error!("Resized index {} from {} to {} bytes", name, current_size, current_size * 2);
 
         let index_path = self.base_path.join(uuid.to_string());
         let index = self.create_or_open_index(&index_path, None, 2 * current_size)?;
`@@` -268,8 +270,10 `@@` impl IndexMapper {
             match index {
                 Some(Available(index)) => break index,
                 Some(BeingResized(ref resize_operation)) => {
+                    log::error!("waiting for resize end");
                     // Deadlock: no lock taken while doing this operation.
                     resize_operation.wait();
+                    log::error!("trying our luck again!");
                     continue;
                 }
                 Some(BeingDeleted) => return Err(Error::IndexNotFound(name.to_string())),
diff --git a/index-scheduler/src/lib.rs b/index-scheduler/src/lib.rs
index 11b17d05..242dc095 100644
--- a/index-scheduler/src/lib.rs
+++ b/index-scheduler/src/lib.rs
`@@` -908,6 +908,7 `@@` impl IndexScheduler {
     ///
     /// Returns the number of processed tasks.
     fn tick(&self) -> Result<TickOutcome> {
+        log::error!("ticking!");
         #[cfg(test)]
         {
             *self.run_loop_iteration.write().unwrap() += 1;
diff --git a/meilisearch/src/main.rs b/meilisearch/src/main.rs
index 050c825a..63f312f6 100644
--- a/meilisearch/src/main.rs
+++ b/meilisearch/src/main.rs
`@@` -25,7 +25,7 `@@` fn setup(opt: &Opt) -> anyhow::Result<()> {
 
 #[actix_web::main]
 async fn main() -> anyhow::Result<()> {
-    let (opt, config_read_from) = Opt::try_build()?;
+    let (mut opt, config_read_from) = Opt::try_build()?;
 
     setup(&opt)?;
 
`@@` -56,6 +56,8 `@@` We generated a secure master key for you (you can safely copy this token):
         _ => (),
     }
 
+    opt.max_index_size = byte_unit::Byte::from_str("1MB").unwrap();
+
     let (index_scheduler, auth_controller) = setup_meilisearch(&opt)?;
 
     #[cfg(all(not(debug_assertions), feature = "analytics"))]
```
</details>

Mainly, these debug changes do the following:

- Set the default index size to 1MiB so that index resizes are initially frequent
- Turn some logs from info to error so that they can be displayed with `--log-level ERROR` (hiding the other infos)
- Add a long sleep between the beginning and the end of the resize so that we can observe the `BeingResized` index status (otherwise it would never come up in my tests)

## Open questions

- Is the growth factor of x2 the correct solution? For a `Vec` in memory it makes sense, but here we're manipulating quantities that are potentially in the order of 500GiBs. For bigger indexes it may make more sense to add at most e.g. 100GiB on each resize operation, avoiding big steps like 500GiB -> 1TiB.

## PR checklist
Please check if your PR fulfills the following requirements:
- [ ] Does this PR fix an existing issue, or have you listed the changes applied in the PR description (and why they are needed)?
- [ ] Have you read the contributing guidelines?
- [ ] Have you made sure that the title is accurate and descriptive of the changes?

Thank you so much for contributing to Meilisearch!


3470: Autobatch addition and deletion r=irevoire a=irevoire

This PR adds the capability to meilisearch to batch document addition and deletion together.

Fix https://github.com/meilisearch/meilisearch/issues/3440

--------------

Things to check before merging;

- [x] What happens if we delete multiple time the same documents -> add a test
- [x] If a documentDeletion gets batched with a documentAddition but the index doesn't exist yet? It should not work

Co-authored-by: Louis Dureuil <louis@meilisearch.com>
Co-authored-by: Tamo <tamo@meilisearch.com>
2023-02-20 15:00:19 +00:00
..
snapshots/lib.rs fix the test to handle the document deletion correctly 2023-02-09 11:29:13 +01:00
autobatcher.rs stop autobatching the deletion without the index creation right with the addition 2023-02-08 21:24:27 +01:00
batch.rs Merge #3319 #3470 2023-02-20 15:00:19 +00:00
error.rs improve the error message when no task filter are specified for the cancelation or deletion of tasks 2023-01-19 12:42:08 +01:00
index_mapper.rs Make sure we don't leave the in memory hashmap in an inconsistent state 2023-02-20 13:55:32 +01:00
insta_snapshot.rs Compute the size of the auth-controller, index-scheduler and all update files in the global stats 2023-01-25 11:25:02 +01:00
lib.rs Merge #3319 #3470 2023-02-20 15:00:19 +00:00
utils.rs get rids of the let/else syntax 2023-02-14 17:45:46 +01:00
uuid_codec.rs Moved the struct UuidCodec to a new file 2022-10-31 12:25:19 +05:30