Thanks Ameya...I will give a try to your ideas...
On Sun, Nov 17, 2013 at 3:17 PM, Ameya Vilankar <ameya.vilan...@gmail.com>wrote: > In your scenario, you want to store some value that is obtained in > Superstep 1, so that it is available to a vertex in all the subsequent > supersteps. The best place to do that is to store it on the vertex itself. > The simplest example is ShortesPath Example where you store the current > lowest distance on the vertex, and when you receive a message you update it > with the new lowest mistake. I assume that in your program you don't want > to update the value after Superstep 1. So don't. Just keep an extra > variable in your vertex value class and set it in superstep 1 so that it > can be used by the vertex in all the following steps. > > But if you want to store global information i.e in superstep 1, every > vertex computes and stores a value and in the subsequent supersteps, a > vertex needs access to the stored values of all the vertices, you need to > make those values global. The only way to do it is to use a persistent > aggregator. In superstep 1, every vertex computes the value and then sends > it to the persistent aggregator that can contain a hashmap from the vertex > id to the value. This value will persist across all the supersteps since > the aggregator is a persistent one. Will be available to every vertex too. > > > On Sun, Nov 17, 2013 at 1:11 AM, Mirko Kämpf <mirko.kae...@cloudera.com>wrote: > >> Hi, >> >> if it is a local value, just important for that given vertex, it might >> work with a local variable, maybe even a more complex data structure, e.g. >> a Stack or a FIFO buffer, to handle "old" data. I do not consider to >> exchange data between vertexes, only within one vertex over time. >> >> I write this here, to share my idea, but I am not really sure if a Giraph >> vertex works like this. It's just how I would try it ... >> >> But I think we will see a definitive answer soon. >> >> Have a nice day! >> Mirko >> >> >> On Sun, Nov 17, 2013 at 6:55 AM, Jyoti Yadav >> <rao.jyoti26ya...@gmail.com>wrote: >> >>> Hi folks... >>> >>> while executing my program ,i came across a doubt which is creating >>> problem... >>> >>> Scenario.... >>> >>> In compute() function, >>> Suppose in superstep1 each vertex want to save some value so that every >>> vertex can use its previously saved value in upcoming supersteps...Is it >>> possible??? >>> >>> >>> Any ideas are really appreciated... >>> >>> Thanks... >>> Jyoti >>> >>> >>> >>> >> >> >> >
