title: spring-boot @scheduled not running in different threads?
body: <p>I am configuring a scheduled task to run in different threads.
  Here is the configuration code</p>
  
  <pre><code>@Configuration
  @EnableScheduling
  public class SchedulerConfig implements SchedulingConfigurer {
      private final int POOL_SIZE = 10;
  
      @Override
      public void configureTasks(ScheduledTaskRegistrar scheduledTaskRegistrar) {
          ThreadPoolTaskScheduler threadPoolTaskScheduler = new ThreadPoolTaskScheduler();
          threadPoolTaskScheduler.setPoolSize(POOL_SIZE);
          threadPoolTaskScheduler.setThreadNamePrefix("my-sched-pool-");
          threadPoolTaskScheduler.initialize();
          scheduledTaskRegistrar.setTaskScheduler(threadPoolTaskScheduler);
      }
  }
  </code></pre>
  
  <p>Here is the code that uses it</p>
  
  <pre><code>@Scheduled(fixedRateString = "2000" )
      public void testaMethod() {
  
           log.debug("here is the message");
          try {
              Thread.sleep(10000);
          } catch (InterruptedException e) {
              e.printStackTrace();
          }
  
      }
  </code></pre>
  
  <p>I am sleeping the thread for 10s with fixedRate of 2s. so I expect to see different threads in the log
  but I see only one</p>
  
  <p>logs are here</p>
  
  <pre><code>{"thread":"my-sched-pool-1","level":"DEBUG","description":"here is the message"}
  {"thread":"my-sched-pool-1","level":"DEBUG","description":"here is the message"}
  {"thread":"my-sched-pool-1","level":"DEBUG","description":"here is the message"}
  {"thread":"my-sched-pool-1","level":"DEBUG","description":"here is the message"}
  </code></pre>