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 15package rafthttp 16 17import ( 18 "bytes" 19 "context" 20 "io" 21 "io/ioutil" 22 "net/http" 23 "time" 24 25 "go.etcd.io/etcd/etcdserver/api/snap" 26 "go.etcd.io/etcd/pkg/httputil" 27 pioutil "go.etcd.io/etcd/pkg/ioutil" 28 "go.etcd.io/etcd/pkg/types" 29 "go.etcd.io/etcd/raft" 30 31 "github.com/dustin/go-humanize" 32 "go.uber.org/zap" 33) 34 35var ( 36 // timeout for reading snapshot response body 37 snapResponseReadTimeout = 5 * time.Second 38) 39 40type snapshotSender struct { 41 from, to types.ID 42 cid types.ID 43 44 tr *Transport 45 picker *urlPicker 46 status *peerStatus 47 r Raft 48 errorc chan error 49 50 stopc chan struct{} 51} 52 53func newSnapshotSender(tr *Transport, picker *urlPicker, to types.ID, status *peerStatus) *snapshotSender { 54 return &snapshotSender{ 55 from: tr.ID, 56 to: to, 57 cid: tr.ClusterID, 58 tr: tr, 59 picker: picker, 60 status: status, 61 r: tr.Raft, 62 errorc: tr.ErrorC, 63 stopc: make(chan struct{}), 64 } 65} 66 67func (s *snapshotSender) stop() { close(s.stopc) } 68 69func (s *snapshotSender) send(merged snap.Message) { 70 start := time.Now() 71 72 m := merged.Message 73 to := types.ID(m.To).String() 74 75 body := createSnapBody(s.tr.Logger, merged) 76 defer body.Close() 77 78 u := s.picker.pick() 79 req := createPostRequest(s.tr.Logger, u, RaftSnapshotPrefix, body, "application/octet-stream", s.tr.URLs, s.from, s.cid) 80 81 if s.tr.Logger != nil { 82 s.tr.Logger.Info( 83 "sending database snapshot", 84 zap.Uint64("snapshot-index", m.Snapshot.Metadata.Index), 85 zap.String("remote-peer-id", to), 86 zap.Int64("bytes", merged.TotalSize), 87 zap.String("size", humanize.Bytes(uint64(merged.TotalSize))), 88 ) 89 } 90 91 snapshotSendInflights.WithLabelValues(to).Inc() 92 defer func() { 93 snapshotSendInflights.WithLabelValues(to).Dec() 94 }() 95 96 err := s.post(req) 97 defer merged.CloseWithError(err) 98 if err != nil { 99 if s.tr.Logger != nil { 100 s.tr.Logger.Warn( 101 "failed to send database snapshot", 102 zap.Uint64("snapshot-index", m.Snapshot.Metadata.Index), 103 zap.String("remote-peer-id", to), 104 zap.Int64("bytes", merged.TotalSize), 105 zap.String("size", humanize.Bytes(uint64(merged.TotalSize))), 106 zap.Error(err), 107 ) 108 } 109 110 // errMemberRemoved is a critical error since a removed member should 111 // always be stopped. So we use reportCriticalError to report it to errorc. 112 if err == errMemberRemoved { 113 reportCriticalError(err, s.errorc) 114 } 115 116 s.picker.unreachable(u) 117 s.status.deactivate(failureType{source: sendSnap, action: "post"}, err.Error()) 118 s.r.ReportUnreachable(m.To) 119 // report SnapshotFailure to raft state machine. After raft state 120 // machine knows about it, it would pause a while and retry sending 121 // new snapshot message. 122 s.r.ReportSnapshot(m.To, raft.SnapshotFailure) 123 sentFailures.WithLabelValues(to).Inc() 124 snapshotSendFailures.WithLabelValues(to).Inc() 125 return 126 } 127 s.status.activate() 128 s.r.ReportSnapshot(m.To, raft.SnapshotFinish) 129 130 if s.tr.Logger != nil { 131 s.tr.Logger.Info( 132 "sent database snapshot", 133 zap.Uint64("snapshot-index", m.Snapshot.Metadata.Index), 134 zap.String("remote-peer-id", to), 135 zap.Int64("bytes", merged.TotalSize), 136 zap.String("size", humanize.Bytes(uint64(merged.TotalSize))), 137 ) 138 } 139 140 sentBytes.WithLabelValues(to).Add(float64(merged.TotalSize)) 141 snapshotSend.WithLabelValues(to).Inc() 142 snapshotSendSeconds.WithLabelValues(to).Observe(time.Since(start).Seconds()) 143} 144 145// post posts the given request. 146// It returns nil when request is sent out and processed successfully. 147func (s *snapshotSender) post(req *http.Request) (err error) { 148 ctx, cancel := context.WithCancel(context.Background()) 149 req = req.WithContext(ctx) 150 defer cancel() 151 152 type responseAndError struct { 153 resp *http.Response 154 body []byte 155 err error 156 } 157 result := make(chan responseAndError, 1) 158 159 go func() { 160 resp, err := s.tr.pipelineRt.RoundTrip(req) 161 if err != nil { 162 result <- responseAndError{resp, nil, err} 163 return 164 } 165 166 // close the response body when timeouts. 167 // prevents from reading the body forever when the other side dies right after 168 // successfully receives the request body. 169 time.AfterFunc(snapResponseReadTimeout, func() { httputil.GracefulClose(resp) }) 170 body, err := ioutil.ReadAll(resp.Body) 171 result <- responseAndError{resp, body, err} 172 }() 173 174 select { 175 case <-s.stopc: 176 return errStopped 177 case r := <-result: 178 if r.err != nil { 179 return r.err 180 } 181 return checkPostResponse(s.tr.Logger, r.resp, r.body, req, s.to) 182 } 183} 184 185func createSnapBody(lg *zap.Logger, merged snap.Message) io.ReadCloser { 186 buf := new(bytes.Buffer) 187 enc := &messageEncoder{w: buf} 188 // encode raft message 189 if err := enc.encode(&merged.Message); err != nil { 190 if lg != nil { 191 lg.Panic("failed to encode message", zap.Error(err)) 192 } 193 } 194 195 return &pioutil.ReaderAndCloser{ 196 Reader: io.MultiReader(buf, merged.ReadCloser), 197 Closer: merged.ReadCloser, 198 } 199} 200