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Fixed delivery of retained messages after transfer.

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I was running a manual test moving from dev to this branch and
noticed that the consumer would receive only 1 message of the 10
messages sent as retained. So I modified the test to verify that
we receive them all and we did not.

The reason was that after the transfer we need to refresh the state
of the stream (stream info) since we attempt to load all messages
based on the state's sequences.

I have also modified a bit the code to update the MaxMsgsPer once
all messages have been transferred.

Signed-off-by: Ivan Kozlovic <ivan@synadia.com>
This commit is contained in:
Ivan Kozlovic
2023-05-31 19:35:12 -06:00
committed by Neil Twigg
parent 4f797a54e0
commit a744cb8cd2
2 changed files with 58 additions and 22 deletions
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61
server/mqtt.go
View File

@@ -1170,17 +1170,40 @@ func (s *Server) mqttCreateAccountSessionManager(acc *Account, quitCh chan struc
if err != nil {
return nil, err
}
as.transferRetainedToPerKeySubjectStream(s)
}
} else {
wantedSubj := mqttRetainedMsgsStreamSubject + as.domainTk + ">"
if len(si.Config.Subjects) != 1 || si.Config.Subjects[0] != wantedSubj {
si.Config.Subjects = []string{wantedSubj}
if _, err := jsa.updateStream(&si.Config); err != nil {
}
// Doing this check outside of above if/else due to possible race when
// creating the stream.
wantedSubj := mqttRetainedMsgsStreamSubject + as.domainTk + ">"
if len(si.Config.Subjects) != 1 || si.Config.Subjects[0] != wantedSubj {
// Update only the Subjects at this stage, not MaxMsgsPer yet.
si.Config.Subjects = []string{wantedSubj}
if si, err = jsa.updateStream(&si.Config); err != nil {
return nil, fmt.Errorf("failed to update stream config: %w", err)
}
}
// Try to transfer regardless if we have already updated the stream or not
// in case not all messages were transferred and the server was restarted.
if as.transferRetainedToPerKeySubjectStream(s) {
// We need another lookup to have up-to-date si.State values in order
// to load all retained messages.
si, err = lookupStream(mqttRetainedMsgsStreamName, "retained messages")
if err != nil {
return nil, err
}
}
// Now, if the stream does not have MaxMsgsPer set to 1, and there are no
// more messages on the single $MQTT.rmsgs subject, update the stream again.
if si.Config.MaxMsgsPer != 1 {
_, err := jsa.loadNextMsgFor(mqttRetainedMsgsStreamName, "$MQTT.rmsgs")
// Looking for an error indicated that there is no such message.
if err != nil && IsNatsErr(err, JSNoMessageFoundErr) {
si.Config.MaxMsgsPer = 1
// We will need an up-to-date si, so don't use local variable here.
if si, err = jsa.updateStream(&si.Config); err != nil {
return nil, fmt.Errorf("failed to update stream config: %w", err)
}
}
as.transferRetainedToPerKeySubjectStream(s)
}
var lastSeq uint64
@@ -2305,21 +2328,10 @@ func (as *mqttAccountSessionManager) transferUniqueSessStreamsToMuxed(log *Serve
retry = false
}
func (as *mqttAccountSessionManager) transferRetainedToPerKeySubjectStream(log *Server) {
func (as *mqttAccountSessionManager) transferRetainedToPerKeySubjectStream(log *Server) bool {
jsa := &as.jsa
var count, errors int
// Set retry to true, will be set to false on success.
defer func() {
if errors > 0 {
next := mqttDefaultTransferRetry
log.Warnf("Failed to transfer %d MQTT retained messages, will try again in %v", errors, next)
time.AfterFunc(next, func() { as.transferRetainedToPerKeySubjectStream(log) })
} else if count > 0 {
log.Noticef("Transfer of %d MQTT retained messages done!", count)
}
}()
for {
// Try and look up messages on the original undivided "$MQTT.rmsgs" subject.
// If nothing is returned here, we assume to have migrated all old messages.
@@ -2331,7 +2343,7 @@ func (as *mqttAccountSessionManager) transferRetainedToPerKeySubjectStream(log *
}
log.Warnf(" Unable to load retained message with sequence %d: %s", smsg.Sequence, err)
errors++
return
break
}
// Unmarshal the message so that we can obtain the subject name.
var rmsg mqttRetainedMsg
@@ -2355,6 +2367,15 @@ func (as *mqttAccountSessionManager) transferRetainedToPerKeySubjectStream(log *
}
count++
}
if errors > 0 {
next := mqttDefaultTransferRetry
log.Warnf("Failed to transfer %d MQTT retained messages, will try again in %v", errors, next)
time.AfterFunc(next, func() { as.transferRetainedToPerKeySubjectStream(log) })
} else if count > 0 {
log.Noticef("Transfer of %d MQTT retained messages done!", count)
}
// Signal if there was any activity (either some transferred or some errors)
return errors > 0 || count > 0
}
//////////////////////////////////////////////////////////////////////////////