khenaidoo | d948f77 | 2021-08-11 17:49:24 -0400 | [diff] [blame] | 1 | // Copyright 2017 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 compactor |
| 16 | |
| 17 | import ( |
| 18 | "context" |
| 19 | "sync" |
| 20 | "time" |
| 21 | |
| 22 | pb "github.com/coreos/etcd/etcdserver/etcdserverpb" |
| 23 | "github.com/coreos/etcd/mvcc" |
| 24 | |
| 25 | "github.com/jonboulle/clockwork" |
| 26 | ) |
| 27 | |
| 28 | // Revision compacts the log by purging revisions older than |
| 29 | // the configured reivison number. Compaction happens every 5 minutes. |
| 30 | type Revision struct { |
| 31 | clock clockwork.Clock |
| 32 | retention int64 |
| 33 | |
| 34 | rg RevGetter |
| 35 | c Compactable |
| 36 | |
| 37 | ctx context.Context |
| 38 | cancel context.CancelFunc |
| 39 | |
| 40 | mu sync.Mutex |
| 41 | paused bool |
| 42 | } |
| 43 | |
| 44 | // NewRevision creates a new instance of Revisonal compactor that purges |
| 45 | // the log older than retention revisions from the current revision. |
| 46 | func NewRevision(retention int64, rg RevGetter, c Compactable) *Revision { |
| 47 | return newRevision(clockwork.NewRealClock(), retention, rg, c) |
| 48 | } |
| 49 | |
| 50 | func newRevision(clock clockwork.Clock, retention int64, rg RevGetter, c Compactable) *Revision { |
| 51 | t := &Revision{ |
| 52 | clock: clock, |
| 53 | retention: retention, |
| 54 | rg: rg, |
| 55 | c: c, |
| 56 | } |
| 57 | t.ctx, t.cancel = context.WithCancel(context.Background()) |
| 58 | return t |
| 59 | } |
| 60 | |
| 61 | const revInterval = 5 * time.Minute |
| 62 | |
| 63 | // Run runs revision-based compactor. |
| 64 | func (t *Revision) Run() { |
| 65 | prev := int64(0) |
| 66 | go func() { |
| 67 | for { |
| 68 | select { |
| 69 | case <-t.ctx.Done(): |
| 70 | return |
| 71 | case <-t.clock.After(revInterval): |
| 72 | t.mu.Lock() |
| 73 | p := t.paused |
| 74 | t.mu.Unlock() |
| 75 | if p { |
| 76 | continue |
| 77 | } |
| 78 | } |
| 79 | |
| 80 | rev := t.rg.Rev() - t.retention |
| 81 | if rev <= 0 || rev == prev { |
| 82 | continue |
| 83 | } |
| 84 | |
| 85 | plog.Noticef("Starting auto-compaction at revision %d (retention: %d revisions)", rev, t.retention) |
| 86 | _, err := t.c.Compact(t.ctx, &pb.CompactionRequest{Revision: rev}) |
| 87 | if err == nil || err == mvcc.ErrCompacted { |
| 88 | prev = rev |
| 89 | plog.Noticef("Finished auto-compaction at revision %d", rev) |
| 90 | } else { |
| 91 | plog.Noticef("Failed auto-compaction at revision %d (%v)", rev, err) |
| 92 | plog.Noticef("Retry after %v", revInterval) |
| 93 | } |
| 94 | } |
| 95 | }() |
| 96 | } |
| 97 | |
| 98 | // Stop stops revision-based compactor. |
| 99 | func (t *Revision) Stop() { |
| 100 | t.cancel() |
| 101 | } |
| 102 | |
| 103 | // Pause pauses revision-based compactor. |
| 104 | func (t *Revision) Pause() { |
| 105 | t.mu.Lock() |
| 106 | defer t.mu.Unlock() |
| 107 | t.paused = true |
| 108 | } |
| 109 | |
| 110 | // Resume resumes revision-based compactor. |
| 111 | func (t *Revision) Resume() { |
| 112 | t.mu.Lock() |
| 113 | defer t.mu.Unlock() |
| 114 | t.paused = false |
| 115 | } |