我有一个spring-boot项目，带有angular2前端，当我运行spring-boot项目并打开redis服务器时，redis服务器显示有两个客户端连接到它。这是为什么？它应该是1个客户端，因为只有spring项目连接到它
Spring-

@Configuration
  @EnableRedisHttpSession
  class RedisSessionConfig {
       @Bean
        public LettuceConnectionFactory connectionFactory() {
            return new LettuceConnectionFactory(); 
        }

  }

@Configuration
@EnableWebSecurity
public class SecurityConfig extends WebSecurityConfigurerAdapter{

    @Autowired
    Environment env; 

    @Autowired
    UserSecurityService useSecurityService;

    private BCryptPasswordEncoder passwordEncoder() {
        return SecurityUtility.passwordEncoder();
    }

    private static final String[] PUBLIC_MATHCES= {
            "/css/**",
            "/js/**",
            "/image/**",
            "/book/**",
            "/user/**"
    };

    @Override
    protected void configure(AuthenticationManagerBuilder auth) throws Exception {
        auth.userDetailsService(useSecurityService).passwordEncoder(passwordEncoder());

    }

    @Override
    protected void configure(HttpSecurity http) throws Exception {
        http.authorizeRequests()
            .antMatchers(PUBLIC_MATHCES).permitAll()
            .anyRequest().authenticated()
            .and();
        http.csrf().disable()
            .cors()
            .and()
            .httpBasic();

    }

      @Bean
      public HttpSessionIdResolver httpSessionStrategy() {
          return  HeaderHttpSessionIdResolver.xAuthToken();
      }

}

@Configuration
public class RedisConfigureAction {
    @Bean
    public ConfigureRedisAction configureRedisAction() {
        return ConfigureRedisAction.NO_OP;
    }
}