4908: Bring back changes from release v1.10.1 to main r=dureuill a=irevoire
# Pull Request
Following the [latest release](https://github.com/meilisearch/meilisearch/releases/tag/v1.10.1), this PR brings back the changes to main.
Co-authored-by: Tamo <tamo@meilisearch.com>
Co-authored-by: irevoire <irevoire@users.noreply.github.com>
4787: Add index exists function in index_scheduler which stops opening indexes to only check if they exist. r=Kerollmops a=Karribalu
# Pull Request
## Related issue
Fixes#4784
## What does this PR do?
- Added index_exists function in the index_scheduler.
- Resolved opening indexes to only check if they exist.
- Made changes to existing tests to test this function.
## PR checklist
Please check if your PR fulfills the following requirements:
- [x] Does this PR fix an existing issue, or have you listed the changes applied in the PR description (and why they are needed)?
- [x] Have you read the contributing guidelines?
- [x] Have you made sure that the title is accurate and descriptive of the changes?
Thank you so much for contributing to Meilisearch!
Co-authored-by: karribalu <karri.balu123456@gmail.com>
4435: Make update file deletion atomic r=Kerollmops a=irevoire
# Pull Request
## Related issue
Fixes https://github.com/meilisearch/meilisearch/issues/4432
Fixes https://github.com/meilisearch/meilisearch/issues/4438 by adding the logs the user asked
## What does this PR do?
- Adds a bunch of logs to help debug this kind of issue in the future
- Delete the update files AFTER committing the update in the `index-scheduler` (thus, if a restart happens, we are able to re-process the batch successfully)
- Multi-thread the deletion of all update files.
Co-authored-by: Tamo <tamo@meilisearch.com>
