Skip to content

[FIXED] Consumer MaxDeliver underflow #7216

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Merged
neilalexander merged 1 commit into from
Aug 26, 2025
Merged

[FIXED] Consumer MaxDeliver underflow #7216

Show file tree
Hide file tree
Changes from all commits
Commits
Show all changes
1 commit
Select commit
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
5 changes: 3 additions & 2 deletions server/consumer.go
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -1107,7 +1107,7 @@ func (mset *stream) addConsumerWithAssignment(config *ConsumerConfig, oname stri
uch: make(chan struct{}, 1),
mch: make(chan struct{}, 1),
sfreq: int32(sampleFreq),
maxdc: uint64(config.MaxDeliver),
maxdc: uint64(max(config.MaxDeliver, 0)), // MaxDeliver is negative (-1) when infinite.
maxp: config.MaxAckPending,
retention: cfg.Retention,
created: time.Now().UTC(),
Expand Down Expand Up @@ -2322,7 +2322,8 @@ func (o *consumer) updateConfig(cfg *ConsumerConfig) error {
}
// Set MaxDeliver if changed
if cfg.MaxDeliver != o.cfg.MaxDeliver {
o.maxdc = uint64(cfg.MaxDeliver)
// MaxDeliver is negative (-1) when infinite.
o.maxdc = uint64(max(cfg.MaxDeliver, 0))
}
// Set InactiveThreshold if changed.
if val := cfg.InactiveThreshold; val != o.cfg.InactiveThreshold {
Expand Down
44 changes: 44 additions & 0 deletions server/jetstream_consumer_test.go
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -10241,3 +10241,47 @@ func TestJetStreamConsumerPrioritized(t *testing.T) {
require_NotNil(t, msg)
})
}

func TestJetStreamConsumerMaxDeliverUnderflow(t *testing.T) {
s := RunBasicJetStreamServer(t)
defer s.Shutdown()

nc, js := jsClientConnect(t, s)
defer nc.Close()

_, err := js.AddStream(&nats.StreamConfig{Name: "TEST", Subjects: []string{"foo"}})
require_NoError(t, err)

cfg := &nats.ConsumerConfig{Durable: "CONSUMER", MaxDeliver: -1}
_, err = js.AddConsumer("TEST", cfg)
require_NoError(t, err)

mset, err := s.globalAccount().lookupStream("TEST")
require_NoError(t, err)
o := mset.lookupConsumer("CONSUMER")
require_NotNil(t, o)

// Infinite MaxDeliver should be zero.
o.mu.RLock()
maxdc := o.maxdc
o.mu.RUnlock()
require_Equal(t, maxdc, 0)

// Finite MaxDeliver should be reported the same.
cfg.MaxDeliver = 1
_, err = js.UpdateConsumer("TEST", cfg)
require_NoError(t, err)
o.mu.RLock()
maxdc = o.maxdc
o.mu.RUnlock()
require_Equal(t, maxdc, 1)

// Infinite MaxDeliver should be zero.
cfg.MaxDeliver = -1
_, err = js.UpdateConsumer("TEST", cfg)
require_NoError(t, err)
o.mu.RLock()
maxdc = o.maxdc
o.mu.RUnlock()
require_Equal(t, maxdc, 0)
}
Loading