@Override
  public void onBlobReplicaPurged(String sourceHost, int port, String blobId, BlobReplicaSourceType sourceType) {
    logger.debug("onBlobReplicaPurged {}, {}, {}, {}", sourceHost, port, blobId, sourceType);
  }
Logs all events at DEBUG level.
ambry-commons/src/main/java/com/github/ambry/commons/LoggingNotificationSystem.java