@Override
  public void updateExtensionLink(ExtensionLinkRequest request) throws AmbariException {
    if (request.getLinkId() == null) {
      throw new AmbariException("Link ID should be provided");
    }
    ExtensionLinkEntity linkEntity = null;
    try {
      linkEntity = linkDAO.findById(Long.parseLong(request.getLinkId()));
    } catch (RollbackException e) {
      throw new AmbariException("Unable to find extension link"
            + ", linkId=" + request.getLinkId(), e);
    }
    updateExtensionLink(linkEntity, request);
  }
Update a link - switch the link's extension version while keeping the same stack version and extension name

@throws AmbariException if we fail to link the extension to the stack
ambari-server/src/main/java/org/apache/ambari/server/controller/AmbariManagementControllerImpl.java