title: Cpu utilization goes really high with for asynch api
body: <p>I have an api that is used to store data in <code>DynamoDB</code>, 
  I am using google's ListeningExecutorService to submit jobs, which eventually sends the data to DB. but the <code>cpu</code> utilization is going really high and i am unable to debug why.</p>
  
  <p>Here is the code :</p>
  
  <pre><code>@Timed(AuditConstants.CRITICAL_TIMER_PREFIX + "sendMessage")
  public void save(Audit audit) {
      Callable callable = new CallableResult(auditRepository,auditDataUtils,audit);
  
      ListenableFuture&lt;Result&gt; future = executorService.submit(callable);
  
      Futures.addCallback(future, new FutureCallback&lt;Result&gt;() {
          @Override
          public void onSuccess(@Nullable Result result) {
              log.info("Successfully sent audit with uuid {} to Dynamo DB", audit.getAuditId());
          }
  
          @Override
          public void onFailure(Throwable throwable) {
              log.info(ERROR_WHILE_SENDING_THE_MESSAGE, throwable);
              handleException(audit, throwable);
          }
      });
  
  }
  
  private void handleException(Audit audit, Throwable ex) {
  
      log.info("Failed talking to Dynamo DB, writing audit with uuid {} to file", audit.getAuditId(), ex);
      producerAuditEventsLogger.logToFile(audit);
  }
  </code></pre>
  
  <p>CallableResult job</p>
  
  <pre><code>@Override
      public Result call() throws Exception {
          try {
              AuditData auditData = auditDataUtils.getAuditData(audit);
              auditRepository.saveAuditData(auditData);
              return new Result(SUCCESS);
          } catch (Exception e) {
              throw new Exception("There was an error while writing to DB",e);
          }
      }
  </code></pre>
  
  <p>The CPU Utilization is reaching upto 70% forr 3 Nodes(c4x large ) for 1300 tps.</p>
  
  <p>The response time is very low ~20ms</p>
  
  <p>Kindly guide me how can I debug , and what are the recommended ways to lower cpu.</p>
  
  <p>Thanks</p>