mongodb/node-mongodb-native · error · MongoRuntimeError

Reauthentication already in progress.

Error message

Reauthentication already in progress.

What it means

Thrown by AuthProvider.reauth when context.reauthenticating is already true — i.e. a re-authentication flow was started and a second one was triggered before the first finished. The driver re-authenticates (e.g. for OIDC token refresh, AWS session expiry, or after a 391 'Reauthenticate' server error) and this guard prevents overlapping flows on the same connection. It is a MongoRuntimeError.

Solutions

1. Let the driver manage re-authentication automatically (do not call internal auth APIs); ensure only one reauth is in flight per connection.
2. For OIDC, implement the token callback to be fast and cached so concurrent reauth attempts resolve quickly and don't pile up.
3. If using short-lived credentials, give them a TTL comfortably longer than operation latency to avoid frequent reauth.
4. Upgrade the driver — reauth concurrency has been refined across releases; a double-dispatch may be a fixed bug.

When it happens

Trigger: Two concurrent operations on a connection both receive a re-authenticate signal and attempt reauth simultaneously; an auth provider's reauth recursively calls reauth; manual invocation of reauth while the SDAM monitor is also re-authenticating.

Common situations: OIDC tokens expiring under high concurrency where multiple connections reauth at once; AWS temporary credentials expiring mid-operation; a server 391 response arriving during an in-flight reauth; driver bug causing double reauth dispatch.

Understand the failure class

• Authentication and authorization failures — expired tokens, bad credentials, and missing scopes.

Related errors

• No workflow provided to the OIDC auth provider.
• username and ENVIRONMENT
• Attempted to get a refresh token when none exists.
• Attempted to get an access token when none exists.
• Attempted to get IDP information when none exists.

AI-assisted analysis of mongodb/node-mongodb-native@dce7939f86 (2026-08-11). Data as JSON: /api/errors/1fc6dcc0561ae231. Report an issue: GitHub.

Appendix: source

Thrown at src/cmap/auth/auth_provider.ts:68

    _authContext: AuthContext
  ): Promise<HandshakeDocument> {
    return handshakeDoc;
  }

  /**
   * Authenticate
   *
   * @param context - A shared context for authentication flow
   */
  abstract auth(context: AuthContext): Promise<void>;

  /**
   * Reauthenticate.
   * @param context - The shared auth context.
   */
  async reauth(context: AuthContext): Promise<void> {
    if (context.reauthenticating) {
      throw new MongoRuntimeError('Reauthentication already in progress.');
    }
    try {
      context.reauthenticating = true;
      await this.auth(context);
    } finally {
      context.reauthenticating = false;
    }
  }
}

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