boolean deleteMetadata(String reason) {
    if (blobMetadataCache == null) {
      return false;
    }
    boolean deleteResult = blobMetadataCache.deleteObject(blobId.toString());
    logger.debug("[{}] Issued delete-metadata for blobId = {}, reason = {}, result = {}",
        blobMetadataCache.getCacheId(), blobId, reason, deleteResult);
    return deleteResult;
  }
Unconditionally deletes blob metadata for composite blobs.
@param reason String describing reason for deletion, useful for triaging.
@return True if metadata was deleted successfully, else False.
ambry-router/src/main/java/com/github/ambry/router/GetBlobOperation.java