anchor.diff:  -define(HTTP_MAX_CONNS, 128).
   
   % How long to keep a PUT request in queue if the system is busy.
  --define(PUT_WAIT_TIMEOUT, 1 * ?MINUTE).
  +-define(PUT_WAIT_TIMEOUT, (1 * ?MINUTE)).
   
   % How long to keep a GET request in queue if the system is busy.
  --define(GET_WAIT_TIMEOUT, 1 * ?MINUTE).
  +-define(GET_WAIT_TIMEOUT, (1 * ?MINUTE)).
   
   % An unused loaded tag expires in TAG_EXPIRES milliseconds.  Note that
   % if TAG_EXPIRES is not smaller than GC_INTERVAL, tags will never
   % expire from the memory cache and will always take up memory.
  --define(TAG_EXPIRES, 10 * ?HOUR).
  +-define(TAG_EXPIRES, (10 * ?HOUR)).
   
   % How often the master's cache of all known tag names is refreshed.
   % This refresh is only needed to purge deleted tags eventually from
   % the tag cache. It doesn't harm to have a long interval.
  --define(TAG_CACHE_INTERVAL, 10 * ?MINUTE).
  +-define(TAG_CACHE_INTERVAL, (10 * ?MINUTE)).
   
   % How soon a tag object initialized in memory expires if it's content
   % cannot be fetched from the cluster.
  --define(TAG_EXPIRES_ONERROR, 1 * ?SECOND).
  +-define(TAG_EXPIRES_ONERROR, (1 * ?SECOND)).
   
   % How often a DDFS node should refresh its tag cache from disk.
   -define(FIND_TAGS_INTERVAL, ?DAY).
  
positive.code: % Timeout for re-replicating a single blob over HTTP PUT.  This
  % depends on the largest blobs hosted by DDFS, and the speed of the
  % cluster network.
  -define(GC_PUT_TIMEOUT, 180 * ?MINUTE).
  
  % Delete !partial files after this many milliseconds.
  -define(PARTIAL_EXPIRES, ?DAY).
  
negative.code: -define(FILE_MODE, 8#00400).
  
  % How often to check available disk space in ddfs_node.
  -define(DISKSPACE_INTERVAL, (10 * ?SECOND)).
  
  % The maximum size of payloads of HTTP requests to the /ddfs/tag/
  % prefix.
  