wei liu 975c91df16
feat: Add comprehensive snapshot functionality for collections (#44361)
issue: #44358

Implement complete snapshot management system including creation,
deletion, listing, description, and restoration capabilities across all
system components.

Key features:
- Create snapshots for entire collections
- Drop snapshots by name with proper cleanup
- List snapshots with collection filtering
- Describe snapshot details and metadata

Components added/modified:
- Client SDK with full snapshot API support and options
- DataCoord snapshot service with metadata management
- Proxy layer with task-based snapshot operations
- Protocol buffer definitions for snapshot RPCs
- Comprehensive unit tests with mockey framework
- Integration tests for end-to-end validation

Technical implementation:
- Snapshot metadata storage in etcd with proper indexing
- File-based snapshot data persistence in object storage
- Garbage collection integration for snapshot cleanup
- Error handling and validation across all operations
- Thread-safe operations with proper locking mechanisms

<!-- This is an auto-generated comment: release notes by coderabbit.ai
-->
- Core invariant/assumption: snapshots are immutable point‑in‑time
captures identified by (collection, snapshot name/ID); etcd snapshot
metadata is authoritative for lifecycle (PENDING → COMMITTED → DELETING)
and per‑segment manifests live in object storage (Avro / StorageV2). GC
and restore logic must see snapshotRefIndex loaded
(snapshotMeta.IsRefIndexLoaded) before reclaiming or relying on
segment/index files.

- New capability added: full end‑to‑end snapshot subsystem — client SDK
APIs (Create/Drop/List/Describe/Restore + restore job queries),
DataCoord SnapshotWriter/Reader (Avro + StorageV2 manifests),
snapshotMeta in meta, SnapshotManager orchestration
(create/drop/describe/list/restore), copy‑segment restore
tasks/inspector/checker, proxy & RPC surface, GC integration, and
docs/tests — enabling point‑in‑time collection snapshots persisted to
object storage and restorations orchestrated across components.

- Logic removed/simplified and why: duplicated recursive
compaction/delta‑log traversal and ad‑hoc lookup code were consolidated
behind two focused APIs/owners (Handler.GetDeltaLogFromCompactTo for
delta traversal and SnapshotManager/SnapshotReader for snapshot I/O).
MixCoord/coordinator broker paths were converted to thin RPC proxies.
This eliminates multiple implementations of the same traversal/lookup,
reducing divergence and simplifying responsibility boundaries.

- Why this does NOT introduce data loss or regressions: snapshot
create/drop use explicit two‑phase semantics (PENDING → COMMIT/DELETING)
with SnapshotWriter writing manifests and metadata before commit; GC
uses snapshotRefIndex guards and
IsRefIndexLoaded/GetSnapshotBySegment/GetSnapshotByIndex checks to avoid
removing referenced files; restore flow pre‑allocates job IDs, validates
resources (partitions/indexes), performs rollback on failure
(rollbackRestoreSnapshot), and converts/updates segment/index metadata
only after successful copy tasks. Extensive unit and integration tests
exercise pending/deleting/GC/restore/error paths to ensure idempotence
and protection against premature deletion.
<!-- end of auto-generated comment: release notes by coderabbit.ai -->

---------

Signed-off-by: Wei Liu <wei.liu@zilliz.com>
2026-01-06 10:15:24 +08:00
..

Go MilvusClient

license Go Reference

Go MilvusClient for Milvus. To contribute code to this project, please read our contribution guidelines first.

Getting started

Prerequisites

Go 1.24.11 or higher

Install Milvus Go SDK

  1. Use go get to install the latest version of the Milvus Go SDK and dependencies:

    go get -u github.com/milvus-io/milvus/client/v2
    
  2. Include the Go MilvusClient in your application:

     import "github.com/milvus-io/milvus/client/v2/milvusclient"
    
     //...other snippet ...
     ctx, cancel := context.WithCancel(context.Background())
     defer cancel()
    
     milvusAddr := "YOUR_MILVUS_ENDPOINT"
    
     cli, err := milvusclient.New(ctx, &milvusclient.ClientConfig{
     	Address: milvusAddr,
     })
     if err != nil {
     	// handle error
     }
    
     // Do your work with milvus client
    

API Documentation

Refer to https://milvus.io/api-reference/go/v2.5.x/About.md for the Go SDK API documentation.

Code format

The Go source code is formatted using gci & gofumpt. Please run make lint-fix before sumbit a PR.