nats-io/nats-server · error

failed to get consumer state for '%s > %s'

Error message

failed to get consumer state for '%s > %s'

What it means

Emitted during a clustered stream snapshot when the internal $JS.API.CLUSTER.CONSUMER.INFO request to a peer replica returns an error or a nil ConsumerInfo for a consumer that has a RAFT assignment. The 'stream > consumer' names identify which assignment's state could not be fetched, so the snapshot cannot capture that consumer's delivered/ack floors.

Source

Thrown at server/stream_backup.go:193

				AckFloor: SequencePair{
					Consumer: ci.AckFloor.Consumer,
					Stream:   ci.AckFloor.Stream,
				},
			}
			if ci.NumAckPending > 0 {
				// Cluster consumer info does not include the sparse pending state.
				// Roll back to the ack floor so all possibly unacknowledged messages
				// are delivered again instead of guessing which ones are pending.
				state.Delivered = state.AckFloor
			}
			return state
		}

		if clustered {
			for _, ca := range consumerAssignments {
				ci, err := sysRequest[ConsumerInfo](js.srv, clusterConsumerInfoT, sa.Client.serviceAccount(), sa.Config.Name, ca.Name)
				if err != nil || ci == nil {
					errCh <- fmt.Errorf("failed to get consumer state for '%s > %s'", sa.Config.Name, ca.Name)
					return
				}
				if err := writeConsumerMsg(SnapshotConsumerState{
					ConsumerConfig: ca.Config,
					ConsumerState:  consumerStateFromInfo(ci),
				}); err != nil {
					errCh <- err
					return
				}
			}
		} else {
			for _, o := range consumerStores {
				config := o.GetConfig()
				state, err := o.State()
				if err != nil {
					errCh <- fmt.Errorf("couldn't load consumer '%s' state: %s", config.Name, err)
					return
				}

View on GitHub (pinned to 3a66a489d2)

Solutions

1. Check JetStream cluster health and consumer replica assignments (stream and consumer RAFT leaders) before starting the snapshot
2. Retry the snapshot after the cluster settles; transient leadership changes can make the internal sysRequest fail
3. Verify the consumer still exists on the expected peer and that the account has the correct permissions for the internal service request

When it happens

Trigger: Thrown at server/stream_backup.go:193 when the library encounters an invalid state.

Common situations: See trigger scenarios.

AI-assisted analysis of nats-io/nats-server@3a66a489d2 (2026-09-02). Data as JSON: /api/errors/03df8efe9096b972. Report an issue: GitHub.