micro/go-micro · error

source loading errors: %s

Error message

source loading errors: %s

What it means

The memory config loader's Sync reloads all configured sources; any per-source read errors are collected into gerr and, if non-empty, returned as a single joined error after the snapshot is still applied. It indicates one or more config sources failed to load, with each underlying message on its own line.

Source

Thrown at config/loader/memory/memory.go:268

	// set values
	vals, err := m.opts.Reader.Values(set)
	if err != nil {
		m.Unlock()
		return err
	}
	m.vals = vals
	m.snap = &loader.Snapshot{
		ChangeSet: set,
		Version:   genVer(),
	}

	m.Unlock()

	// update watchers
	m.update()

	if len(gerr) > 0 {
		return fmt.Errorf("source loading errors: %s", strings.Join(gerr, "\n"))
	}

	return nil
}

func (m *memory) Close() error {
	m.closeMu.Lock()
	defer m.closeMu.Unlock()

	if m.closed {
		return nil
	}

	close(m.exit)
	m.closed = true
	return nil
}

View on GitHub (pinned to 24529f1404)

Solutions

1. Parse the error string: each line after the prefix is one source's error; fix the underlying source listed
2. Check connectivity/credentials for the failing backend and retry Sync
3. Make sources resilient or remove/disable the failing source from the loader
4. Verify the source's key/path exists and has non-empty content before loading

Example fix

// before
if err := loader.Sync(); err != nil { log.Fatal(err) } // opaque joined error
// after
if err := loader.Sync(); err != nil {
    for _, line := range strings.Split(err.Error(), "\n") { log.Warn(line) }
    // fall back to last good snapshot
}

// before syncing, sanity-check each source is reachable/readable
for _, s := range sources {
    if _, err := s.Read(); err != nil {
        log.Warn("source unavailable, will use last good snapshot:", err)
    }
}

if err := loader.Sync(); err != nil {
    for _, line := range strings.Split(err.Error(), "\n") {
        log.Error("config source error: ", line)
    }
    // keep serving last good snapshot; do not crash
}

When it happens

Trigger: Calling loader.Sync (directly or via Snapshot/Get on an auto-synced loader) when any source's Read fails — e.g. an unreachable config server, expired credentials, or a malformed remote config.

Common situations: A config backend (file removed, etcd/consul/nats down) becoming unavailable between reloads; bad credentials after rotation; a source added to the loader pointing at a non-existent path or key.

Related errors

• no values
• <joined load errors>
• watcher is disabled
• watcher stopped
• changeset is nil

AI-assisted analysis of micro/go-micro@24529f1404 (2026-09-01). Data as JSON: /api/errors/6ee0aae80d03010d. Report an issue: GitHub.