apache/rocketmq · error · AuthenticationException

username can not be blank

Error message

username can not be blank

What it means

deleteUser rejected the call because the username argument is null, empty, or whitespace-only (StringUtils.isBlank). deleteUser also cascades an ACL deletion for the user, so a blank name could not resolve either operation.

Source

Thrown at auth/src/main/java/org/apache/rocketmq/auth/authentication/manager/AuthenticationMetadataManagerImpl.java:146

                    old.setUserType(user.getUserType());
                }
                if (user.getUserStatus() != null) {
                    old.setUserStatus(user.getUserStatus());
                }
                return this.getAuthenticationMetadataProvider().updateUser(old);
            });
        } catch (Exception e) {
            this.handleException(e, result);
        }
        return result;
    }

    @Override
    public CompletableFuture<Void> deleteUser(String username) {
        CompletableFuture<Void> result = new CompletableFuture<>();
        try {
            if (StringUtils.isBlank(username)) {
                throw new AuthenticationException("username can not be blank");
            }
            CompletableFuture<Void> deleteUser = this.getAuthenticationMetadataProvider().deleteUser(username);
            CompletableFuture<Void> deleteAcl = this.getAuthorizationMetadataProvider().deleteAcl(User.of(username));
            return CompletableFuture.allOf(deleteUser, deleteAcl);
        } catch (Exception e) {
            this.handleException(e, result);
        }
        return result;
    }

    @Override
    public CompletableFuture<User> getUser(String username) {
        CompletableFuture<User> result = new CompletableFuture<>();
        try {
            if (StringUtils.isBlank(username)) {
                throw new AuthenticationException("username can not be blank");
            }
            result = this.getAuthenticationMetadataProvider().getUser(username);

View on GitHub (pinned to 293f588571)

Solutions

1. Pass a concrete, trimmed username to deleteUser.
2. Validate required CLI/API arguments before invoking the manager.
3. Log the offending input at the call site to catch empty propagation early.

Example fix

// before
authManager.deleteUser(username); // username == null

// after
if (StringUtils.isBlank(username)) throw new IllegalArgumentException("username required");
authManager.deleteUser(username.trim());

if (username == null || username.trim().isEmpty()) {
    throw new IllegalArgumentException("username must be provided for deleteUser");
}
authManager.deleteUser(username.trim());

boolean isDeletableUser(String u) { return u != null && !u.trim().isEmpty(); }

catch (AuthenticationException e) { if message contains "blank" -> fix caller input plumbing; this is a client bug, never retry. }

When it happens

Trigger: Invoking deleteUser(null), deleteUser(""), or deleteUser(" ") - commonly when a variable holding the username failed to populate from CLI args, config, or an upstream API payload.

Common situations: Admin tooling or scripts passing an unset option (-u omitted); deserialized User/DTO with null username reaching the delete path; UI form submitted empty.

Related errors

• user can not be null
• password can not be blank
• authentication credential length is incorrect, actual length
• User:{} is not found.
• The user is existed

AI-assisted analysis of apache/rocketmq@293f588571 (2026-08-14). Data as JSON: /api/errors/5aece7953e21019c. Report an issue: GitHub.