What causes "could not get last config for channel %s" in hyperledger/fabric?

Wait until the peer has committed the channel's latest config block, then retry the config query

could not get last config for channel %s

Error message

could not get last config for channel %s

What it means

DiscoverySupport.Config builds the channel's config result from the peer's current channel config. If GetCurrConfig(channel) returns nil — the service holds no last-config for that channel — it cannot produce a ConfigResult and returns this error.

Source

Thrown at discovery/support/config/support.go:57

// DiscoverySupport implements support that is used for service discovery
// that is related to configuration
type DiscoverySupport struct {
	CurrentConfigGetter
}

// NewDiscoverySupport creates a new DiscoverySupport
func NewDiscoverySupport(getLastConfig CurrentConfigGetter) *DiscoverySupport {
	return &DiscoverySupport{
		CurrentConfigGetter: getLastConfig,
	}
}

// Config returns the channel's configuration
func (s *DiscoverySupport) Config(channel string) (*discovery.ConfigResult, error) {
	config := s.GetCurrConfig(channel)
	if config == nil {
		return nil, errors.Errorf("could not get last config for channel %s", channel)
	}

	if err := ValidateConfig(config); err != nil {
		return nil, errors.WithMessage(err, "config is invalid")
	}

	res := &discovery.ConfigResult{
		Msps:     make(map[string]*msp.FabricMSPConfig),
		Orderers: make(map[string]*discovery.Endpoints),
	}
	ordererGrp := config.ChannelGroup.Groups[channelconfig.OrdererGroupKey].Groups
	appGrp := config.ChannelGroup.Groups[channelconfig.ApplicationGroupKey].Groups

	var globalEndpoints []string
	globalOrderers := config.ChannelGroup.Values[channelconfig.OrdererAddressesKey]
	if globalOrderers != nil {
		ordererAddressesConfig := &common.OrdererAddresses{}
		if err := proto.Unmarshal(globalOrderers.Value, ordererAddressesConfig); err != nil {

View on GitHub (pinned to 2736b63f8f)

Solutions

Wait until the peer has committed the channel's latest config block, then retry the config query
Verify the channel name and that the peer joined it (peer channel list)
Check peer logs for ledger/config load failures that would leave GetCurrConfig nil

Defensive patterns

Strategy: retry

Validate before calling

// query after the peer reports the channel as active
status := getChannelStatus(peerEndpoint, channelID)
if status != "active" {
    return fmt.Errorf("channel %s not active yet", channelID)
}

Try / catch

var res *discovery.ConfigResult
err := retry.Do(func() error {
    r, err := client.Send(ctx, req)
    if err != nil && strings.Contains(err.Error(), "could not get last config") {
        return retry.RetryableError(err) // config may still be loading
    }
    res = r
    return err
})

Prevention

Delay config queries until after the peer commits the channel config block
Verify channel name and peer membership before querying
Alert on peer ledger/config load failures

When it happens

Trigger: A discovery config query for a channel the peer hasn't joined or whose config hasn't been loaded into the config service; also hit in unit tests when the fake GetCurrConfig returns nil.

Common situations: Config query issued immediately after channel creation before the peer processes the config block; peer joined to a different channel than requested; name typo in the discovery request.

Related errors

AI-assisted analysis of hyperledger/fabric@2736b63f8f (2026-09-04). Data as JSON: /api/errors/33852010b9b2bb5a. Report an issue: GitHub.