dd6a411e5e
issue: #49831 ## What changed Vendor Milvus design documents into this repository under `docs/design-docs` as regular tracked files. - Keep only the design document content and assets under `docs/design-docs/design_docs/` and `docs/design-docs/assets/`. - Remove standalone repository metadata from the vendored directory, such as `README.md`, `CONTRIBUTING.md`, `MEP-TEMPLATE.md`, `COMMITTERS`, `MAINTAINERS`, `OWNERS`, `OWNERS_ALIASES`, and `.gitignore`. - Document the Milvus design document process in the main `CONTRIBUTING.md`. - Update Mergify and `tools/mgit.py` so feature PRs must provide an in-repo design document path under `docs/design-docs/design_docs/`. ## Why Milvus feature work should have an associated design document. Keeping design docs directly in this repository makes them available from a normal Milvus checkout and lets feature implementations include or link the related design document in the same repository. ## Verification - `git diff --check` - `python3 -m unittest tools/test_mgit_design_doc.py` - `python3 -m py_compile tools/mgit.py tools/test_mgit_design_doc.py` - Parsed `.github/mergify.yml` with Python `yaml.safe_load` - Confirmed `docs/design-docs` only contains `assets/` and `design_docs/` at the top level --------- Signed-off-by: xiaofanluan <xiaofan.luan@zilliz.com> Co-authored-by: Claude Opus 4.7 <noreply@anthropic.com>
2.7 KiB
DropCollection release resources
Before this enhancement
When dropping a collection
- DataNode releases the flowgraph of this collection and drops all the data in a buffer.
- DataCoord has no idea whether a collection is dropped or not.
- DataCoord will make DataNode watch DmChannels of dropped collections.
- Blob files will never be removed even if the collection is dropped.
For not in used binlogs on blob storage: Why are there such binlogs
- A failure flush.
- A failure compaction.
- Dropped and out-of timetravel collection binlogs.
This enhancement is focused on solving these 2 problems.
Object1 DropCollection
DataNode ignites Flush&Drop receive drop collection msg -> cancel compaction -> flush all insert buffer and delete buffer -> release the flowgraph
Plan 1: Picked
Add a dropped flag in SaveBinlogPathRequest proto.
DataNode
- Flush all segments in this vChannel, When Flush&Drop, set the
droppedflag true.- If fails, retry at most 10 times and restart.
DataCoord
- DataCoord marks segmentInfo as
dropped, doesn't remove segmentInfos from etcd. - When recovery, check if the segments in the vchannel are all dropped.
- if not, recover before the drop.
- if so, no need to recover the vchannel.
Pros: 1. The easiest approach in both DataNode and DataCoord. 2. DataNode can reuse the current flush manager procedure. Cons: 1. The No. rpc call is equal to the No. segments in a collection, expensive.
Plan 2: Enhance later
Add a new rpc FlushAndDrop, it's a vchannel scope rpc.
Pros: 1. much lesser rpc calls, equal to shard-numbers. 2. More clarity of flush procedure in DataNode. Cons: 1. More efforts in DataNode and DataCoord.
message FlushAndDropRequest {
common.MsgBase base = 1;
string channelID = 2;
int64 collectionID = 3;
repeated SegmentBinlogPaths segment_binlog_paths = 6;
}
message SegmentBinlogPaths {
int64 segmentID = 1;
CheckPoint checkPoint = 2;
repeated FieldBinlog field2BinlogPaths = 2;
repeated FieldBinlog field2StatslogPaths = 3;
repeated DeltaLogInfo deltalogs = 4;
}
Object2: DataCoord Garbage Collection (GC) for not in used binlogs
How to clear unknown binlogs?
DataCoord runs a background GC goroutine, triggers every 1 day:
- Get all minIO/S3 paths(keys).
- Filter out keys not in segmentInfo.
- According to the meta of blobs from minIO/S3, remove binlogs that exist more than 1 day.
- **Why 1 day: **Maybe there are newly uploaded binlogs from flush/compaction
How to clear dropped-collection's binlogs?
- DataCoord checks all dropped-segments, removes the binlogs recorded if they've been dropped by 1 day.
- DataCoord keeps the etcd segmentInfo meta.