Gelly Scatter/Gather - Vertex update

[Alieh Saeedi]

Hi everybody

In Gelly scatter/gather when no message is sent to a vertex in one iteration, it will not enter the scatter function in next iteration. Why? I need all vertices enter the scatter function in all iterations, but some of them receive a message and will be updated.

thanks in advance

[Vasiliki Kalavri]

Hi Alieh,

the scatter-gather model is built on top of Flink delta iterations exactly for the reason to allow de-activating vertices that do not need to participate in the computation of a certain superstep. If you want all vertices to participate in all iterations of scatter-gather, you can send dummy messages to keep them active. However, the scatter-gather model might not be the correct model for your use-case and you might want to look into Flink bulk iteration operators instead [1].

-Vasia.

[1]: https://ci.apache.org/projects/flink/flink-docs-master/apis/batch/index.html#iteration-operators

On 14 June 2016 at 12:21, Alieh Saeedi <[hidden email]> wrote:

Hi everybody

In Gelly scatter/gather when no message is sent to a vertex in one iteration, it will not enter the scatter function in next iteration. Why? I need all vertices enter the scatter function in all iterations, but some of them receive a message and will be updated.

thanks in advance