Flink JobGraph生成源码解析

public static JobGraph getJobGraph(
            @Nonnull final Pipeline pipeline, @Nonnull final Configuration configuration)

JobGraph translateToJobGraph(
            Pipeline pipeline, Configuration optimizerConfiguration, int defaultParallelism);

 private JobGraph createJobGraph() {
        preValidate();
        jobGraph.setJobType(streamGraph.getJobType());
![image.png](https://p1-juejin.byteimg.com/tos-cn-i-k3u1fbpfcp/0603957ea34f4d6b9af96b686bd5fdb1~tplv-k3u1fbpfcp-watermark.image?)
        jobGraph.enableApproximateLocalRecovery(
                streamGraph.getCheckpointConfig().isApproximateLocalRecoveryEnabled());
        // Generate deterministic hashes for the nodes in order to identify them across
        // submission iff they didn't change.
        Map<Integer, byte[]> hashes =
                defaultStreamGraphHasher.traverseStreamGraphAndGenerateHashes(streamGraph);
        // Generate legacy version hashes for backwards compatibility
        List<Map<Integer, byte[]>> legacyHashes = new ArrayList<>(legacyStreamGraphHashers.size());
        for (StreamGraphHasher hasher : legacyStreamGraphHashers) {
            legacyHashes.add(hasher.traverseStreamGraphAndGenerateHashes(streamGraph));
        }
        setChaining(hashes, legacyHashes);
        setPhysicalEdges();
        setSlotSharingAndCoLocation();
        setManagedMemoryFraction(
                Collections.unmodifiableMap(jobVertices),
                Collections.unmodifiableMap(vertexConfigs),
                Collections.unmodifiableMap(chainedConfigs),
                id -> streamGraph.getStreamNode(id).getManagedMemoryOperatorScopeUseCaseWeights(),
                id -> streamGraph.getStreamNode(id).getManagedMemorySlotScopeUseCases());
        configureCheckpointing();
        jobGraph.setSavepointRestoreSettings(streamGraph.getSavepointRestoreSettings());
        final Map<String, DistributedCache.DistributedCacheEntry> distributedCacheEntries =
                JobGraphUtils.prepareUserArtifactEntries(
                        streamGraph.getUserArtifacts().stream()
                                .collect(Collectors.toMap(e -> e.f0, e -> e.f1)),
                        jobGraph.getJobID());
        for (Map.Entry<String, DistributedCache.DistributedCacheEntry> entry :
                distributedCacheEntries.entrySet()) {
            jobGraph.addUserArtifact(entry.getKey(), entry.getValue());
        }
        // set the ExecutionConfig last when it has been finalized
        try {
            jobGraph.setExecutionConfig(streamGraph.getExecutionConfig());
        } catch (IOException e) {
            throw new IllegalConfigurationException(
                    "Could not serialize the ExecutionConfig."
                            + "This indicates that non-serializable types (like custom serializers) were registered");
        }
        addVertexIndexPrefixInVertexName();
        setVertexDescription();
        return jobGraph;
    }

    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 (!(upStreamVertex.isSameSlotSharingGroup(downStreamVertex)
                && areOperatorsChainable(upStreamVertex, downStreamVertex, streamGraph)
                && arePartitionerAndExchangeModeChainable(
                        edge.getPartitioner(),
                        edge.getExchangeMode(),
                        streamGraph.getExecutionConfig().isDynamicGraph())
                && upStreamVertex.getParallelism() == downStreamVertex.getParallelism()
                && streamGraph.isChainingEnabled())) {
            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;
    }