Solved it by using clue from http://docs.spring.io/spring/docs/4.0.1.RELEASE/javadoc-api/index.html?org/springframework/web/socket/sockjs/SockJsService.html -got hold of ServletServerContainerFactoryBean and set the properties, this worked
@Bean
public ServletServerContainerFactoryBean createServletServerContainerFactoryBean() {
ServletServerContainerFactoryBean container = new ServletServerContainerFactoryBean();
container.setMaxTextMessageBufferSize(32768);
container.setMaxBinaryMessageBufferSize(32768);
logger.info("Websocket factory returned");
return container;
}