Yuchen Liang a889a49e06 pageserver: do vectored read on each dio-aligned section once (#8763) ...

Part of #8130, closes #8719.

## Problem

Currently, vectored blob io only coalesce blocks if they are immediately
adjacent to each other. When we switch to Direct IO, we need a way to
coalesce blobs that are within the dio-aligned boundary but has gap
between them.

## Summary of changes

- Introduces a `VectoredReadCoalesceMode` for `VectoredReadPlanner` and
`StreamingVectoredReadPlanner` which has two modes:
  - `AdjacentOnly` (current implementation)
  - `Chunked(<alignment requirement>)`
- New `ChunkedVectorBuilder` that considers batching `dio-align`-sized
read, the start and end of the vectored read will respect
`stx_dio_offset_align` / `stx_dio_mem_align` (`vectored_read.start` and
`vectored_read.blobs_at.first().start_offset` will be two different
value).
- Since we break the assumption that blobs within single `VectoredRead`
are next to each other (implicit end offset), we start to store blob end
offsets in the `VectoredRead`.
- Adapted existing tests to run in both `VectoredReadCoalesceMode`.
- The io alignment can also be live configured at runtime.

Signed-off-by: Yuchen Liang <yuchen@neon.tech>

2024-08-28 15:54:42 +01:00

..

src

pageserver: do vectored read on each dio-aligned section once (#8763)

2024-08-28 15:54:42 +01:00

Cargo.toml

pageserver: remove depenency of pagebench on pageserver (#6334)

2024-01-12 17:11:19 +00:00