t8y2/dbx · error

Unsupported writeMode: %s

Error message

Unsupported writeMode: %s

What it means

The put operation supports a fixed set of writeMode values (e.g. create/overwrite variants). When handed a mode string it does not recognize, put returns this error instead of guessing a default write behavior.

Source

Thrown at agents/drivers/zookeeper/operations.go:144

			if err != nil {
				return nil, err
			}
			return putResult(stat), nil
		}
		if err := createParents(client, parentPath(path)); err != nil {
			return nil, err
		}
		createdPath, err := client.Create(path, data, 0)
		if err != nil {
			return nil, err
		}
		_, stat, err := client.Get(createdPath)
		if err != nil {
			return nil, err
		}
		return putResult(stat), nil
	default:
		return nil, fmt.Errorf("Unsupported writeMode: %s", writeMode)
	}
}

func createNode(client znodeClient, path string, data []byte, mode string) (map[string]any, error) {
	flags, err := createFlags(mode)
	if err != nil {
		return nil, err
	}
	if err := createParents(client, parentPath(path)); err != nil {
		return nil, err
	}
	createdPath, err := client.Create(path, data, flags)
	if err != nil {
		return nil, err
	}
	_, stat, err := client.Get(createdPath)
	if err != nil {
		return nil, err

View on GitHub (pinned to c0390bff16)

Solutions

1. Use one of the writeMode values the driver accepts (inspect the switch in put in operations.go).
2. Fix casing/typos — mode strings are compared literally.
3. Validate/normalize the mode at the application boundary before calling put.
4. If a new mode is genuinely needed, extend the switch in put and its tests.

Example fix

// before
put(client, path, data, "upsert")
// after
put(client, path, data, "overwrite") // accepted mode per operations.go

var validWriteModes = map[string]bool{"create": true, "overwrite": true /* per put() in operations.go */}
func validWriteMode(m string) bool { return validWriteModes[m] }

res, err := put(client, path, data, mode)
if err != nil {
	if strings.HasPrefix(err.Error(), "Unsupported writeMode:") {
		return nil, fmt.Errorf("writeMode %q rejected; allowed modes: %v", mode, writeModeList)
	}
	return nil, err
}

When it happens

Trigger: Calling put (directly or via dispatch / KV write API) with a writeMode string outside the accepted set — misspelled, wrong casing, or a mode from a different driver's vocabulary.

Common situations: Config-driven write pipelines where the mode comes from user input or YAML config, refactoring that renamed a mode constant, or tests/callers passing "upsert" or "append" which this driver does not implement.

Related errors

• ZooKeeper server list is empty
• ZooKeeper auth scheme and credentials must be configured tog
• Unsupported auth_scheme %q; expected %q or %q
• base_sleep_time_ms must be non-negative
• max_retries must be non-negative

AI-assisted analysis of t8y2/dbx@c0390bff16 (2026-09-05). Data as JSON: /api/errors/a5f72f8eae0684ef. Report an issue: GitHub.