hi Thomas, I want to use an aggregator to store an HashMap, and in every superstep, different vertexes may put or remove an element<key, value> to the HashMap, and I am wondering at the sync phase,if the master will automatic sync the HashMap?
Just like this: superstep n: HashMap: 1,2,3,4,5,6 task1 modified the aggregator: HashMap(1): 3,4,5,6(task1 remove 1,2) task2 modified the aggregator: HashMap(2): 1,2,3,4,5,6,7,8(task2 add 7,8) .... and after the sync phase also in next superstep: the HashMap become: 3,4,5,6,7,8 Did I got it? the namenode will automatic do this? On Thu, Nov 29, 2012 at 8:52 PM, lee fei <[email protected]> wrote: > Thanks for you quick reply:) > > Best wishes for you:D > > > On Thu, Nov 29, 2012 at 8:01 PM, Thomas Jungblut < > [email protected]> wrote: > >> Yes, if they are Writable and are part of your vertex message or value >> type. >> You may want to have a look at MapWritable or other serializable >> collections in the org.apache.hadoop.io package. >> >> 2012/11/29 lee fei <[email protected]> >> >> > Hi, >> > >> > I am a newbie to hama,Can Aggregator in graph package store an >> Arraylist >> > or a HashMap for some special usages? >> > >> > Thank you for you attention~ >> > >> > >
