go.etcd.io/etcd@v3.3.27+incompatible/mvcc/kvstore_compaction.go (about)

     1  // Copyright 2015 The etcd Authors
     2  //
     3  // Licensed under the Apache License, Version 2.0 (the "License");
     4  // you may not use this file except in compliance with the License.
     5  // You may obtain a copy of the License at
     6  //
     7  //     http://www.apache.org/licenses/LICENSE-2.0
     8  //
     9  // Unless required by applicable law or agreed to in writing, software
    10  // distributed under the License is distributed on an "AS IS" BASIS,
    11  // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
    12  // See the License for the specific language governing permissions and
    13  // limitations under the License.
    14  
    15  package mvcc
    16  
    17  import (
    18  	"encoding/binary"
    19  	"time"
    20  )
    21  
    22  func (s *store) scheduleCompaction(compactMainRev int64, keep map[revision]struct{}) bool {
    23  	totalStart := time.Now()
    24  	defer func() { dbCompactionTotalDurations.Observe(float64(time.Since(totalStart) / time.Millisecond)) }()
    25  	keyCompactions := 0
    26  	defer func() { dbCompactionKeysCounter.Add(float64(keyCompactions)) }()
    27  
    28  	end := make([]byte, 8)
    29  	binary.BigEndian.PutUint64(end, uint64(compactMainRev+1))
    30  
    31  	batchsize := int64(10000)
    32  	last := make([]byte, 8+1+8)
    33  	for {
    34  		var rev revision
    35  
    36  		start := time.Now()
    37  		tx := s.b.BatchTx()
    38  		tx.Lock()
    39  
    40  		keys, _ := tx.UnsafeRange(keyBucketName, last, end, batchsize)
    41  		for _, key := range keys {
    42  			rev = bytesToRev(key)
    43  			if _, ok := keep[rev]; !ok {
    44  				tx.UnsafeDelete(keyBucketName, key)
    45  				keyCompactions++
    46  			}
    47  		}
    48  
    49  		if len(keys) < int(batchsize) {
    50  			rbytes := make([]byte, 8+1+8)
    51  			revToBytes(revision{main: compactMainRev}, rbytes)
    52  			tx.UnsafePut(metaBucketName, finishedCompactKeyName, rbytes)
    53  			tx.Unlock()
    54  			plog.Printf("finished scheduled compaction at %d (took %v)", compactMainRev, time.Since(totalStart))
    55  			return true
    56  		}
    57  
    58  		// update last
    59  		revToBytes(revision{main: rev.main, sub: rev.sub + 1}, last)
    60  		tx.Unlock()
    61  		dbCompactionPauseDurations.Observe(float64(time.Since(start) / time.Millisecond))
    62  
    63  		select {
    64  		case <-time.After(100 * time.Millisecond):
    65  		case <-s.stopc:
    66  			return false
    67  		}
    68  	}
    69  }