hama-commits mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From Apache Wiki <wikidi...@apache.org>
Subject [Hama Wiki] Update of "Aggregators" by AnastasisAndronidis
Date Sun, 26 Jan 2014 15:31:35 GMT
Dear Wiki user,

You have subscribed to a wiki page or wiki category on "Hama Wiki" for change notification.

The "Aggregators" page has been changed by AnastasisAndronidis:
https://wiki.apache.org/hama/Aggregators?action=diff&rev1=2&rev2=3

  == Aggregators ==
  
  === Description ===
- Quoting from Pregel paper:
- ''aggregators are a mechanism for global communica- tion, monitoring, and data. Each vertex
can provide a value to an aggregator in superstep S, the system combines those values using
a reduction operator, and the resulting value is made available to all vertices in superstep
S + 1.''
+ Quoting from Pregel paper: ''aggregators are a mechanism for global communication, monitoring,
and data. Each vertex can provide a value to an aggregator in superstep S, the system combines
those values using a reduction operator, and the resulting value is made available to all
vertices in superstep S + 1.''
  
- which allow global communication by receiving messages from multiple vertices, combining
them and sending the result back to the vertices. They are useful for statistics (think of
an histogram of vertex degrees) or for global controlling
+ You can think aggregators as a tree, that the leafs (which are the graph vertices) are sending
messages to the root (the master aggregator), and then the root is combining all these messages
to a value. In the end, this combined values is distributed back to the leafs. Aggregators
are useful for statistics (think of an histogram of vertex degrees) or for global controlling.
  
  === Introduction ===
  

Mime
View raw message