On 25.7.2014 10:56, Carmen Manzulli wrote:
ah ok, thanksa lot!...so is the same for edgevalues and
targetvertexids??? i need to use combiners, can you show me where can
i read more information about?
I have never used the feature so I dont know much about it.
See source code.
For example ByteArrayPartition.java:183:
/**
* Combine two vertices together and store the serialized bytes
* in the vertex map.
*
* @param representativeVertex existing vertex
* @param representativeCombinerVertex new vertex to combine
*/
private void combine(Vertex<I, V, E> representativeVertex,
Vertex<I, V, E> representativeCombinerVertex) {
getVertexValueCombiner().combine(representativeVertex.getValue(),
representativeCombinerVertex.getValue());
// Add the edges to the representative vertex
for (Edge<I, E> edge : representativeCombinerVertex.getEdges()) {
representativeVertex.addEdge(edge);
}
vertexMap.put(representativeCombinerVertex.getId(),
WritableUtils.writeVertexToByteArray(
representativeVertex, useUnsafeSerialization, getConf()));
}
By default Giraph uses DefaultVertexValueCombiner which does nothing.
2014-07-25 10:52 GMT+02:00 Lukas Nalezenec
<lukas.naleze...@firma.seznam.cz
<mailto:lukas.naleze...@firma.seznam.cz>>:
Hi,
Afaik vertex ids must be unique but you can combine vertexes with
same ID to one using VertexValueCombiner.
Lukas
On 25.7.2014 10:33, Carmen Manzulli wrote:
Hi experts,
i would like to ask you if , in the graph rapresentation, every
time a vertexId is reapeated, would giraph consider just one time
that vertexId?
for example:
Carmen (vertexId) 24 (vertex value) .....
Carmen (vertexId) 1,60 m (vertex value)...
does it became
Carmen -->24
-->1,60
from a point of view conceptual?
