func (p *protocolV2) messagePump(client *nsqd.ClientV2, startedChan chan bool,
stoppedChan chan bool) {
var err error
var buf bytes.Buffer
var clientMsgChan chan *nsqd.Message
var subChannel *nsqd.Channel
// NOTE: `flusherChan` is used to bound message latency for
// the pathological case of a channel on a low volume topic
// with >1 clients having >1 RDY counts
var flusherChan <-chan time.Time
var sampleRate int32
subEventChan := client.SubEventChan
identifyEventChan := client.IdentifyEventChan
outputBufferTicker := time.NewTicker(client.OutputBufferTimeout)
heartbeatTicker := time.NewTicker(client.HeartbeatInterval)
heartbeatChan := heartbeatTicker.C
heartbeatFailedCnt := 0
msgTimeout := client.MsgTimeout
// v2 opportunistically buffers data to clients to reduce write system calls
// we force flush in two cases:
// 1. when the client is not ready to receive messages
// 2. we're buffered and the channel has nothing left to send us
// (ie. we would block in this loop anyway)
//
flushed := true
// signal to the goroutine that started the messagePump
// that we've started up
close(startedChan)
for {
if subChannel == nil || !client.IsReadyForMessages() {
// the client is not ready to receive messages...
clientMsgChan = nil
flusherChan = nil
// force flush
client.LockWrite()
err = client.Flush()
client.UnlockWrite()
if err != nil {
goto exit
}
flushed = true
} else if flushed {
// last iteration we flushed...
// do not select on the flusher ticker channel
clientMsgChan = subChannel.GetClientMsgChan()
flusherChan = nil
} else {
// we're buffered (if there isn't any more data we should flush)...
// select on the flusher ticker channel, too
clientMsgChan = subChannel.GetClientMsgChan()
flusherChan = outputBufferTicker.C
}
select {
case <-client.ExitChan:
goto exit
case <-flusherChan:
// if this case wins, we're either starved
// or we won the race between other channels...
// in either case, force flush
client.LockWrite()
err = client.Flush()
client.UnlockWrite()
if err != nil {
goto exit
}
flushed = true
case <-client.ReadyStateChan:
case subChannel = <-subEventChan:
// you can't SUB anymore
nsqd.NsqLogger().Logf("client %v sub to channel: %v", client.ID,
subChannel.GetName())
subEventChan = nil
case identifyData := <-identifyEventChan:
// you can't IDENTIFY anymore
identifyEventChan = nil
outputBufferTicker.Stop()
if identifyData.OutputBufferTimeout > 0 {
outputBufferTicker = time.NewTicker(identifyData.OutputBufferTimeout)
}
heartbeatTicker.Stop()
heartbeatChan = nil
if identifyData.HeartbeatInterval > 0 {
heartbeatTicker = time.NewTicker(identifyData.HeartbeatInterval)
heartbeatChan = heartbeatTicker.C
}
if identifyData.SampleRate > 0 {
sampleRate = identifyData.SampleRate
}
msgTimeout = identifyData.MsgTimeout
case <-heartbeatChan:
if subChannel != nil && client.IsReadyForMessages() {
// try wake up the channel
subChannel.TryWakeupRead()
}
err = Send(client, frameTypeResponse, heartbeatBytes)
nsqd.NsqLogger().LogDebugf("PROTOCOL(V2): [%s] send heartbeat", client)
if err != nil {
heartbeatFailedCnt++
nsqd.NsqLogger().LogWarningf("PROTOCOL(V2): [%s] send heartbeat failed %v times, %v", client, heartbeatFailedCnt, err)
if heartbeatFailedCnt > 2 {
goto exit
}
} else {
heartbeatFailedCnt = 0
}
case msg, ok := <-clientMsgChan:
if !ok {
goto exit
}
if sampleRate > 0 && rand.Int31n(100) > sampleRate {
// FIN automatically, all message will not wait to confirm if not sending,
// and the reader keep moving forward.
offset, _, _, _ := subChannel.ConfirmBackendQueue(msg)
// TODO: sync to replica nodes.
_ = offset
continue
}
// avoid re-send some confirmed message,
// this may happen while the channel reader is reset to old position
// due to some retry or leader change.
if subChannel.IsConfirmed(msg) {
continue
}
subChannel.StartInFlightTimeout(msg, client.ID, client.String(), msgTimeout)
client.SendingMessage()
err = SendMessage(client, msg, &buf, subChannel.IsOrdered())
if err != nil {
goto exit
}
flushed = false
}
}
exit:
nsqd.NsqLogger().LogDebugf("PROTOCOL(V2): [%s] exiting messagePump", client)
heartbeatTicker.Stop()
outputBufferTicker.Stop()
if err != nil {
nsqd.NsqLogger().Logf("PROTOCOL(V2): [%s] messagePump error - %s", client, err)
}
close(stoppedChan)
}
func (self *NsqdCoordinator) FinishMessageToCluster(channel *nsqd.Channel, clientID int64, clientAddr string, msgID nsqd.MessageID) error {
topicName := channel.GetTopicName()
partition := channel.GetTopicPart()
coord, checkErr := self.getTopicCoord(topicName, partition)
if checkErr != nil {
return checkErr.ToErrorType()
}
var syncOffset ChannelConsumerOffset
changed := false
var confirmed nsqd.BackendQueueEnd
if channel.IsOrdered() {
if !coord.GetData().IsISRReadyForWrite() {
coordLog.Warningf("topic(%v) finish message ordered failed since no enough ISR", topicName)
coordErrStats.incWriteErr(ErrWriteQuorumFailed)
return ErrWriteQuorumFailed.ToErrorType()
}
confirmed = channel.GetConfirmed()
}
// TODO: maybe use channel to aggregate all the sync of message to reduce the rpc call.
doLocalWrite := func(d *coordData) *CoordErr {
offset, cnt, tmpChanged, localErr := channel.FinishMessage(clientID, clientAddr, msgID)
if localErr != nil {
coordLog.Infof("channel %v finish local msg %v error: %v", channel.GetName(), msgID, localErr)
changed = false
return &CoordErr{localErr.Error(), RpcNoErr, CoordLocalErr}
}
changed = tmpChanged
syncOffset.VOffset = int64(offset)
syncOffset.VCnt = cnt
return nil
}
doLocalExit := func(err *CoordErr) {}
doLocalCommit := func() error {
channel.ContinueConsumeForOrder()
return nil
}
doLocalRollback := func() {
if channel.IsOrdered() && confirmed != nil {
coordLog.Warningf("rollback channel confirm to : %v", confirmed)
// reset read to last confirmed
channel.SetConsumeOffset(confirmed.Offset(), confirmed.TotalMsgCnt(), true)
}
}
doRefresh := func(d *coordData) *CoordErr {
return nil
}
doSlaveSync := func(c *NsqdRpcClient, nodeID string, tcData *coordData) *CoordErr {
if !changed || channel.IsEphemeral() {
return nil
}
var rpcErr *CoordErr
if channel.IsOrdered() {
// if ordered, we need make sure all the consume offset is synced to all replicas
rpcErr = c.UpdateChannelOffset(&tcData.topicLeaderSession, &tcData.topicInfo, channel.GetName(), syncOffset)
} else {
c.NotifyUpdateChannelOffset(&tcData.topicLeaderSession, &tcData.topicInfo, channel.GetName(), syncOffset)
}
if rpcErr != nil {
coordLog.Infof("sync channel(%v) offset to replica %v failed: %v, offset: %v", channel.GetName(),
nodeID, rpcErr, syncOffset)
}
return rpcErr
}
handleSyncResult := func(successNum int, tcData *coordData) bool {
// we can ignore the error if this channel is not ordered. (just sync next time)
if successNum == len(tcData.topicInfo.ISR) || !channel.IsOrdered() {
return true
}
return false
}
clusterErr := self.doSyncOpToCluster(false, coord, doLocalWrite, doLocalExit, doLocalCommit, doLocalRollback,
doRefresh, doSlaveSync, handleSyncResult)
if clusterErr != nil {
return clusterErr.ToErrorType()
}
return nil
}