flink的webui 各种数字的意义
背景
webui对于刚刚入门flink的人来说，不仅仅可以了解基础概念，还能了解各种各种内容的区别。
- task
- subtask
- operator
- operator chain
- slot
task和subtask和operator
- operator 是一个算子
- 一个subtask可以视为一个线程
- operator chain由operator组成
- 一个subtask（或者说是一个线程）包括一个operator chain
- 一个slot 维护了一个资源集合（cpu/内存），一个slot可以包括多个subtask（多个线程）
operator chains 生成条件
public static boolean isChainable(StreamEdge edge, StreamGraph streamGraph) {
StreamNode downStreamVertex = streamGraph.getTargetVertex(edge);
return downStreamVertex.getInEdges().size() == 1 && isChainableInput(edge, streamGraph);
}
private static boolean isChainableInput(StreamEdge edge, StreamGraph streamGraph) {
StreamNode upStreamVertex = streamGraph.getSourceVertex(edge);
StreamNode downStreamVertex = streamGraph.getTargetVertex(edge);
if (!(streamGraph.isChainingEnabled()
&& upStreamVertex.isSameSlotSharingGroup(downStreamVertex)
&& areOperatorsChainable(upStreamVertex, downStreamVertex, streamGraph)
&& arePartitionerAndExchangeModeChainable(
edge.getPartitioner(), edge.getExchangeMode(), streamGraph.isDynamic()))) {
return false;
}
// check that we do not have a union operation, because unions currently only work
// through the network/byte-channel stack.
// we check that by testing that each "type" (which means input position) is used only once
for (StreamEdge inEdge : downStreamVertex.getInEdges()) {
if (inEdge != edge && inEdge.getTypeNumber() == edge.getTypeNumber()) {
return false;
}
}
return true;
}