title: Apache Nifi missing files when using ListGCSBucket and FetchGCSObject processors
body: <p>We have a nifi processor group to transfer files between 2 Google Cloud Storage buckets say BucketA and BucketB (in different Google Cloud projects). For this we are using below Nifi processors in order:</p>
  <ol>
  <li>ListGCSBucket</li>
  <li>FetchGCSObject</li>
  <li>PutGCSObject</li>
  </ol>
  <p>At the end of the day we have found that there are some files which are not present in BucketB. Our files in BucketA are uploaded each minute and Nifi ListGCS is scheduled to run at every 30 seconds.</p>
  <p>Could it be due to some race condition like when ListGCS is working, at the same time a file is uploaded in BucketA and missed by ListGCS and not picked in the next run as well ?</p>