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https://gitee.com/milvus-io/milvus.git
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c7b5c23ff6
issue: #46540 Empty timetick is just used to sync up the time clock between different component in milvus. So empty timetick can be ignored if we achieve the lsn/mvcc semantic for timetick. Currently, some components need the empty timetick to trigger some operation, such as flush/tsafe. So we only slow down the empty time tick for 5 seconds. <!-- This is an auto-generated comment: release notes by coderabbit.ai --> - Core invariant: with LSN/MVCC semantics consumers only need (a) the first timetick that advances the latest-required-MVCC to unblock MVCC-dependent waits and (b) occasional periodic timeticks (~≤5s) for clock synchronization—therefore frequent non-persisted empty timeticks can be suppressed without breaking MVCC correctness. - Logic removed/simplified: per-message dispatch/consumption of frequent non-persisted empty timeticks is suppressed — an MVCC-aware filter emptyTimeTickSlowdowner (internal/util/pipeline/consuming_slowdown.go) short-circuits frequent empty timeticks in the stream pipeline (internal/util/pipeline/stream_pipeline.go), and the WAL flusher rate-limits non-persisted timetick dispatch to one emission per ~5s (internal/streamingnode/server/flusher/flusherimpl/wal_flusher.go); the delegator exposes GetLatestRequiredMVCCTimeTick to drive the filter (internal/querynodev2/delegator/delegator.go). - Why this does NOT introduce data loss or regressions: the slowdowner always refreshes latestRequiredMVCCTimeTick via GetLatestRequiredMVCCTimeTick and (1) never filters timeticks < latestRequiredMVCCTimeTick (so existing tsafe/flush waits stay unblocked) and (2) always lets the first timetick ≥ latestRequiredMVCCTimeTick pass to notify pending MVCC waits; separately, WAL flusher suppression applies only to non-persisted timeticks and still emits when the 5s threshold elapses, preserving periodic clock-sync messages used by flush/tsafe. - Enhancement summary (where it takes effect): adds GetLatestRequiredMVCCTimeTick on ShardDelegator and LastestMVCCTimeTickGetter, wires emptyTimeTickSlowdowner into NewPipelineWithStream (internal/util/pipeline), and adds WAL flusher rate-limiting + metrics (internal/streamingnode/server/flusher/flusherimpl/wal_flusher.go, pkg/metrics) to reduce CPU/dispatch overhead while keeping MVCC correctness and periodic synchronization. <!-- end of auto-generated comment: release notes by coderabbit.ai --> --------- Signed-off-by: chyezh <chyezh@outlook.com>
62 lines
1.6 KiB
Go
62 lines
1.6 KiB
Go
// Licensed to the LF AI & Data foundation under one
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// or more contributor license agreements. See the NOTICE file
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// distributed with this work for additional information
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// regarding copyright ownership. The ASF licenses this file
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// to you under the Apache License, Version 2.0 (the
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// "License"); you may not use this file except in compliance
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// with the License. You may obtain a copy of the License at
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//
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// http://www.apache.org/licenses/LICENSE-2.0
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//
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// Unless required by applicable law or agreed to in writing, software
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// distributed under the License is distributed on an "AS IS" BASIS,
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// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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// See the License for the specific language governing permissions and
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// limitations under the License.
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package funcutil
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import (
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"fmt"
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"math/rand"
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)
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var letterRunes = []byte("abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ")
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// RandomBytes returns a batch of random string
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func RandomBytes(n int) []byte {
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b := make([]byte, n)
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for i := range b {
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b[i] = letterRunes[rand.Intn(len(letterRunes))]
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}
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return b
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}
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// RandomString returns a batch of random string
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func RandomString(n int) string {
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return string(RandomBytes(n))
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}
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// GenRandomBytes generates a random bytes.
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func GenRandomBytes() []byte {
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l := rand.Uint64()%10 + 1
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b := make([]byte, l)
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if _, err := rand.Read(b); err != nil {
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return nil
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}
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return b
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}
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func GenRandomBytesWithLength(length int64) []byte {
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b := make([]byte, length)
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if _, err := rand.Read(b); err != nil {
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return nil
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}
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return b
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}
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// GenRandomStr generates a random string.
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func GenRandomStr() string {
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return fmt.Sprintf("%X", GenRandomBytes())
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}
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