OpenCDN

File Release Notes and Changelog

Release Name: 0.6.6

Notes:
This OpenCDN release changes the routing algorithm, making it more
distributed, and fixes some bugs.


Changes:
* Bug fixed about empty FP in Surro global hash. It arose because
  RRDMlib::prune don't saves FP_by_node information for LH within the TR hash.
  On the contrary, nodes do return the LH node address as the last entry of
  the visited nodes list, because it is needed for the proper building of
  the %peers global hash. The solution has been to avoid populating %surro,
  if FP_by_node is missing.
* Bug fixed about local FH pruning if wider TR exists, in Setup.xpl.
  When the FH list is checked against the TR one, and a FH is removed if it
  also is a TR with a wider FP, the comparison is now made by using as FP
  for the TR, the Origin-related FootPrint, because the client-related ones
  may not overlap. Thanks to 18.171.6.130 for having evidenced this problem
  by it's log record :-)
* Major change in the routing algorithm, which is more distributed now.
  RRDM no more performs loop avoidance, i.e. in SetUp, it no more removes
  all the TR which are more specific than TR nodes which happens to be also
  LastHop. Instead, loop avoidance is performed by nodes themselves. In fact,
  when a lazy TR Node forwards the DoRealy to another TR:
  - checks that a LH, with a FP which is more specific than the FP of the
    next hop TR, do exist; if not, TR node becomes labour, and forwards
    the DoRelay directly to LH nodes
  - if next hop still is a TR, the forwarded LH list is pruned as well, by
    retaining only LH nodes whose FootPrint is more specific than the
    next hop TR one
 * After some test, another LastHop self-loop escape has been added to
    NodeLib::Transit.
    - When no TR do answer to the UDP poll, or when no LH more specific than
      selected TR in the list do exists, the node switch to labour behavior.
      But, the node itself can be present in the LH list, and in this case,
      self-polling would cause a deadlock. So, this condition is checked,
      sel-polling is avoided, the node itself auto-wins, and self-loop is
      detected later.
      This applyes also when Node is a labour TR, in which case the LH list
      will be checked for this condition, only if Node is not a LH itself.