| // Copyright 2017 The etcd Authors |
| // |
| // Licensed under the Apache License, Version 2.0 (the "License"); |
| // you may not use this file except in compliance with the License. |
| // You may obtain a copy of the License at |
| // |
| // http://www.apache.org/licenses/LICENSE-2.0 |
| // |
| // Unless required by applicable law or agreed to in writing, software |
| // distributed under the License is distributed on an "AS IS" BASIS, |
| // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| // See the License for the specific language governing permissions and |
| // limitations under the License. |
| |
| package compactor |
| |
| import ( |
| "context" |
| "sync" |
| "time" |
| |
| pb "github.com/coreos/etcd/etcdserver/etcdserverpb" |
| "github.com/coreos/etcd/mvcc" |
| |
| "github.com/jonboulle/clockwork" |
| ) |
| |
| // Revision compacts the log by purging revisions older than |
| // the configured reivison number. Compaction happens every 5 minutes. |
| type Revision struct { |
| clock clockwork.Clock |
| retention int64 |
| |
| rg RevGetter |
| c Compactable |
| |
| ctx context.Context |
| cancel context.CancelFunc |
| |
| mu sync.Mutex |
| paused bool |
| } |
| |
| // NewRevision creates a new instance of Revisonal compactor that purges |
| // the log older than retention revisions from the current revision. |
| func NewRevision(retention int64, rg RevGetter, c Compactable) *Revision { |
| return newRevision(clockwork.NewRealClock(), retention, rg, c) |
| } |
| |
| func newRevision(clock clockwork.Clock, retention int64, rg RevGetter, c Compactable) *Revision { |
| t := &Revision{ |
| clock: clock, |
| retention: retention, |
| rg: rg, |
| c: c, |
| } |
| t.ctx, t.cancel = context.WithCancel(context.Background()) |
| return t |
| } |
| |
| const revInterval = 5 * time.Minute |
| |
| // Run runs revision-based compactor. |
| func (t *Revision) Run() { |
| prev := int64(0) |
| go func() { |
| for { |
| select { |
| case <-t.ctx.Done(): |
| return |
| case <-t.clock.After(revInterval): |
| t.mu.Lock() |
| p := t.paused |
| t.mu.Unlock() |
| if p { |
| continue |
| } |
| } |
| |
| rev := t.rg.Rev() - t.retention |
| if rev <= 0 || rev == prev { |
| continue |
| } |
| |
| plog.Noticef("Starting auto-compaction at revision %d (retention: %d revisions)", rev, t.retention) |
| _, err := t.c.Compact(t.ctx, &pb.CompactionRequest{Revision: rev}) |
| if err == nil || err == mvcc.ErrCompacted { |
| prev = rev |
| plog.Noticef("Finished auto-compaction at revision %d", rev) |
| } else { |
| plog.Noticef("Failed auto-compaction at revision %d (%v)", rev, err) |
| plog.Noticef("Retry after %v", revInterval) |
| } |
| } |
| }() |
| } |
| |
| // Stop stops revision-based compactor. |
| func (t *Revision) Stop() { |
| t.cancel() |
| } |
| |
| // Pause pauses revision-based compactor. |
| func (t *Revision) Pause() { |
| t.mu.Lock() |
| defer t.mu.Unlock() |
| t.paused = true |
| } |
| |
| // Resume resumes revision-based compactor. |
| func (t *Revision) Resume() { |
| t.mu.Lock() |
| defer t.mu.Unlock() |
| t.paused = false |
| } |