Files
e2787d3981 enhance: standardize error handling on merr + Sys/Input classification (#50221)
issue: #47420

## What this PR does

Project-wide migration of raw `fmt.Errorf` / `errors.New` in function
bodies onto
the `merr` framework, plus the Sys-vs-Input error classification and the
machinery it drives (retriability, fine-grained metrics, segcore
unification),
plus the convention docs and a linter that keeps it from regressing.

Scope: storage, proxy, coordinators (root/data/query), query node, data
node,
`pkg/util` & `internal/util`, expression parser, message queue,
streaming, and
misc packages. Bare raw-error usages went from ~3000 to a ~340 allowlist
(package-level sentinels / build-tag / test sites).

---

## How to review this PR

It is large but the vast majority is mechanical. Changes fall into three
tiers;
spend review budget on Part 2 and Part 3.

### Part 1 — Mechanical standardization (low risk, verify by rule)

Each converted call follows one of a small fixed set of rules. To
review, check
that each site obeys the matching rule rather than reading every line:

| Pattern | Rule |
|---|---|
| `fmt.Errorf("...")` originating a new error | →
`merr.WrapErrXxxMsg("...")` with a code matching the failure's meaning |
| Adding context to an existing typed error | → `merr.Wrap(err, "...")`
/ `merr.Wrapf(...)` — **preserves** the inner code (never `WrapErr*Err`,
which overwrites it) |
| Errors inside the streaming subsystem | → `status.New*` factories
(StreamingError), **not** merr — this is the component-internal dialect
(see `docs/dev/error_handling_guide.md`) |
| Low-level / control-flow signal caught by `errors.Is` | → kept as a
package-level `errors.New` sentinel (lowercase, same-package) |

Conventions are documented in `docs/dev/error_handling_guide.md`
(how-to) and
`docs/dev/error_sentinel_convention.md` (rules + audit). A
`gocritic`/`ruleguard`
rule (`rawmerrerror`, in `rules.go`) enforces "no raw `return
errors.New/fmt.Errorf`"
under `make verifiers`.

### Part 2 — Behavior changes (review these closely)

These are the sites where the wire contract or runtime behavior changes,
not just
the source text. Listed by category; representative locations given,
full set in
the diff.

**A. gRPC wire-code shifts: `UnexpectedError(1)/Code 65535` → typed
code.**
Where a handler previously returned a raw error (collapsed to
`Code=65535` on the
wire), it now returns a typed merr, so the client sees a real code. The
most
common shift is to `IllegalArgument(5)/Code 1100` (ParameterInvalid).
Touch
points include datanode task handlers (CreateTask/Query/Drop), proxy
Upsert,
querynode GetMetrics, datacoord CreateIndex, httpserver query-response
builder,
and typeutil schema validation. One code refinement: an index-param
validation
moved `1100` → `1101` (ParameterMissing). **Client/SDK assertions and
any code
that switched on `Code=65535` for these paths must be re-checked** (the
go_client
e2e assertions were already aligned in this PR).

**B. Prometheus `status` label contract change (externally visible).**
The proxy metric's coarse `fail` / `rejected` values are split into
`fail_input` / `fail_system` and `rejected_user` / `rejected_system` (in
`requestutil.ParseMetricLabel`; auth/privilege rejections count as
`rejected_user`), so dashboards can attribute a failure to caller vs
operator.
**Dashboards/alerts querying `status="fail"` must migrate to
`status=~"fail_.*"`, and `status="rejected"` to
`status=~"rejected_.*"`.** The
in-repo Grafana dashboard is already migrated; external dashboards built
on the
old values silently go empty after upgrade. This is the one change that
requires an ops-side migration.

**C. Retriability semantics.**
- C1: `merr.Status(err)` now forces `Retriable=false` when the error is
an
`InputError` — a malformed request can never succeed on blind retry, so
clients
never get the self-contradictory "your input is wrong but you may
retry".
- C2: `retry.Do` short-circuits an `InputError` (non-retriable) — **but
only when
  the caller did not pass a `RetryErr` predicate**. The check is an
`if c.isRetryErr != nil { ... } else if InputError { ... }` *mutually
exclusive*
branch (`pkg/util/retry/retry.go`): an explicit `RetryErr` takes
precedence and
bypasses the InputError abort. `retry.Handle` deliberately does **not**
apply
the InputError abort (its callers signal abort via `shouldRetry=false`).
Four
flusher startup callsites that must retry through transient "not ready"
errors
  were given explicit `RetryErr` escape hatches.

**D. segcore (C++→Go) error classification.**
A single shared Go-side table (`pkg/util/merr/segcore.go`) maps each
segcore code
to a merr sentinel + InputError/signal category, replacing scattered
hand-written
`if errorCode == ...` switches in the cgo wrappers. **Wire `Code` values
change
for every segcore pass-through error, not just the remapped ones.**
Named
sentinels remap (C++ `2003` → merr `2001`, `2033` → `2002`,
Folly/Knowhere codes
likewise); **all remaining pass-through codes (`2004`–`2043`, previously
surfaced to clients as raw C++ enum values) now serialize as `2000`**
(`ErrSegcore`), with the original C++ code preserved in the `Reason`
text
(`segcoreCode=...`); unknown/future codes collapse to `2000` as well
(pinned by
the `wire_code_projection` test). Transient segcore classes (object
storage /
file IO / OOM / mmap / FieldNotLoaded — 11 codes) now report
`Retriable=true`.
**Any client switching on raw segcore codes in the `2004`–`2043` range
must be
re-checked**; the in-Reason code remains available for diagnostics.
Signal
codes (PretendFinished / FollyCancel) are recognized centrally.
`errors.Is`-based
control flow on these (e.g. scheduler skip/retry) is preserved.

**E. InputError classification (25 sentinels + dynamic marks).**
25 sentinels in `errors.go` carry `WithErrorType(InputError)` (the
Collection /
ResourceGroup / Database families, `ErrIndexDuplicate`,
`ErrParameterInvalid`,
`ErrPrivilegeNotAuthenticated`, `ErrImportFailed`, `ErrQueryPlan`, ...),
plus dynamic
marks for the 8 segcore input codes (ExprInvalid, DimNotMatch,
MetricTypeInvalid, FieldIDInvalid, ...) and
`WrapErrAsInputError`. The widest blast radius is `ErrParameterInvalid`
(1100):
~2335 `WrapErrParameterInvalid*` callsites now classify as input /
non-retriable. Because of C1/C2 this changes retriability for
any path that returns these. **The audit to confirm no transient path
was
mis-marked is the single most important review item** (see Part 3). One
reverse
correction: storage field-stats parsing moved from `ErrParameterInvalid`
(input)
to `ErrDataIntegrity` — a corrupted stored stat is data corruption, not
user
input.

### Part 3 — Known risks & traps (called out proactively)

1. **`merr.Wrap` vs `WrapErr*Err` (code-masking).** `WrapErr*Err` builds
a
`wrappedMilvusError{sentinel: ErrServiceInternal}` whose `code()`
returns the
*outer* sentinel — it overwrites the inner typed code and hides the
`errors.Is`
chain. This is intentional (use it to *deliberately* downgrade), but it
was a
recurring conversion defect; the rule "add context with `merr.Wrap`,
downgrade
with `WrapErr*Err`" is enforced by convention and reviewed across the
diff.
2. **InputError × `retry.Do` blast radius.** Marking a sentinel
`InputError` makes
any `retry.Do(...)` without a `RetryErr` predicate stop retrying it.
Reviewers
should sanity-check that no transient use of the 19 newly-marked
sentinels
(especially `ErrParameterInvalid`) sits inside a retry loop that needed
to keep
   spinning. The known flusher cases were handled (see C2).
3. **The ~340 raw-error allowlist.** What remains as bare `errors.New`
is, by
design: package-level sentinels (caught by `errors.Is`), `//go:build
test`
sites, and out-of-band trees (`cmd/`, `tests/`, codegen, walimpls). The
linter
only bans the *direct-return* form; assignment-then-return escapes and
the full
no-exceptions ban are deferred to an AST-based linter (Tier 2,
documented).
4. **segcore C++ second step deferred.** This PR unifies classification
on the Go
side; splitting the dual-semantic C++ codes at the source is a
follow-up.

---

## Validation

- `make verifiers`: Go side clean (gofmt + static-check across modules,
including
  the new `rawmerrerror` rule with a 0-hit baseline repo-wide).
- `make test-go`: passing; the one real regression introduced (a
datanode
`invalid_task_type` assertion shifting `1` → `5` from a ParameterInvalid
  conversion) was fixed in-tree.
- go_client e2e CreateIndex assertions aligned to the new merr messages.

---------

Signed-off-by: zhenshan.cao <zhenshan.cao@zilliz.com>
Co-authored-by: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
2026-06-12 15:04:51 -07:00

153 lines
4.0 KiB
Go

package idalloc
import (
"context"
"time"
"github.com/cockroachdb/errors"
"github.com/milvus-io/milvus-proto/go-api/v3/commonpb"
"github.com/milvus-io/milvus/internal/types"
"github.com/milvus-io/milvus/pkg/v3/proto/rootcoordpb"
"github.com/milvus-io/milvus/pkg/v3/util/commonpbutil"
"github.com/milvus-io/milvus/pkg/v3/util/merr"
"github.com/milvus-io/milvus/pkg/v3/util/paramtable"
"github.com/milvus-io/milvus/pkg/v3/util/syncutil"
)
var (
errExhausted = errors.New("exhausted")
errFastPathFailed = errors.New("fast path failed")
)
// newLocalAllocator creates a new local allocator.
func newLocalAllocator() *localAllocator {
return &localAllocator{
nextStartID: 0,
endStartID: 0,
}
}
// localAllocator allocates timestamp locally.
type localAllocator struct {
nextStartID uint64 // Allocate timestamp locally.
endStartID uint64
}
// AllocateOne allocates a timestamp.
func (a *localAllocator) allocateOne() (uint64, error) {
if a.nextStartID < a.endStartID {
id := a.nextStartID
a.nextStartID++
return id, nil
}
return 0, errExhausted
}
// update updates the local allocator.
func (a *localAllocator) update(start uint64, count int) {
// local allocator can be only increasing.
if start >= a.endStartID {
a.nextStartID = start
a.endStartID = start + uint64(count)
}
}
// expire expires all id in the local allocator.
func (a *localAllocator) exhausted() {
a.nextStartID = a.endStartID
}
// tsoAllocator allocate timestamp from remote root coordinator.
type tsoAllocator struct {
mix *syncutil.Future[types.MixCoordClient]
nodeID int64
}
// newTSOAllocator creates a new remote allocator.
func newTSOAllocator(mix *syncutil.Future[types.MixCoordClient]) *tsoAllocator {
a := &tsoAllocator{
nodeID: paramtable.GetNodeID(),
mix: mix,
}
return a
}
func (ta *tsoAllocator) batchAllocate(ctx context.Context, count uint32) (uint64, int, error) {
ctx, cancel := context.WithTimeout(ctx, 10*time.Second)
defer cancel()
req := &rootcoordpb.AllocTimestampRequest{
Base: commonpbutil.NewMsgBase(
commonpbutil.WithMsgType(commonpb.MsgType_RequestTSO),
commonpbutil.WithMsgID(0),
commonpbutil.WithSourceID(ta.nodeID),
),
Count: count,
}
mixc, err := ta.mix.GetWithContext(ctx)
if err != nil {
return 0, 0, merr.Wrap(err, "get root coordinator client timeout")
}
resp, err := mixc.AllocTimestamp(ctx, req)
if err != nil {
return 0, 0, merr.Wrap(err, "syncTimestamp Failed")
}
if resp.GetStatus().GetErrorCode() != commonpb.ErrorCode_Success {
return 0, 0, merr.Wrap(merr.Error(resp.GetStatus()), "syncTimeStamp Failed")
}
if resp == nil {
return 0, 0, merr.WrapErrServiceInternalMsg("empty AllocTimestampResponse")
}
return resp.GetTimestamp(), int(resp.GetCount()), nil
}
// idAllocator allocate timestamp from remote root coordinator.
type idAllocator struct {
mix *syncutil.Future[types.MixCoordClient]
nodeID int64
}
// newIDAllocator creates a new remote allocator.
func newIDAllocator(mix *syncutil.Future[types.MixCoordClient]) *idAllocator {
a := &idAllocator{
nodeID: paramtable.GetNodeID(),
mix: mix,
}
return a
}
func (ta *idAllocator) batchAllocate(ctx context.Context, count uint32) (uint64, int, error) {
ctx, cancel := context.WithTimeout(ctx, 10*time.Second)
defer cancel()
req := &rootcoordpb.AllocIDRequest{
Base: commonpbutil.NewMsgBase(
commonpbutil.WithMsgType(commonpb.MsgType_RequestID),
commonpbutil.WithMsgID(0),
commonpbutil.WithSourceID(ta.nodeID),
),
Count: count,
}
mix, err := ta.mix.GetWithContext(ctx)
if err != nil {
return 0, 0, merr.Wrap(err, "get root coordinator client timeout")
}
resp, err := mix.AllocID(ctx, req)
if err != nil {
return 0, 0, merr.Wrap(err, "AllocID Failed")
}
if resp.GetStatus().GetErrorCode() != commonpb.ErrorCode_Success {
return 0, 0, merr.Wrap(merr.Error(resp.GetStatus()), "AllocID Failed")
}
if resp == nil {
return 0, 0, merr.WrapErrServiceInternalMsg("empty AllocID")
}
if resp.GetID() < 0 {
panic("get unexpected negative id")
}
return uint64(resp.GetID()), int(resp.GetCount()), nil
}