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https://issues.apache.org/jira/browse/BEAM-4658?focusedWorklogId=127656&page=com.atlassian.jira.plugin.system.issuetabpanels:worklog-tabpanel#worklog-127656
]
ASF GitHub Bot logged work on BEAM-4658:
----------------------------------------
Author: ASF GitHub Bot
Created on: 26/Jul/18 06:09
Start Date: 26/Jul/18 06:09
Worklog Time Spent: 10m
Work Description: youngoli commented on a change in pull request #6050:
[BEAM-4658] Update pipeline representation in runner support libraries to
handle timers.
URL: https://github.com/apache/beam/pull/6050#discussion_r205290440
##########
File path:
runners/core-construction-java/src/main/java/org/apache/beam/runners/core/construction/graph/Networks.java
##########
@@ -193,29 +201,55 @@ public final NodeT apply(NodeT input) {
"Only networks without self loops are supported, given %s",
network);
- // Linked hashset will prevent duplicates from appearing and will maintain
insertion order.
- LinkedHashSet<NodeT> nodes = new LinkedHashSet<>(network.nodes().size());
- Queue<NodeT> processingOrder = new ArrayDeque<>();
- // Add all the roots
- for (NodeT node : network.nodes()) {
- if (network.inDegree(node) == 0) {
- processingOrder.add(node);
- }
- }
+ // Uses the following algorithm:
Review comment:
Using this algorithm for topological order doesn't seem appropriate. From
what I could understand from the paper, this algorithm generates a vertex
sequence that makes it easy to remove feedback arcs (i.e. eliminate any
cycles), but doesn't actually maintain topological order.
As a concrete example, if you had a graph that looked like so:
```
Source1 --\
---> A ---> B ---> Sink
Source2 --/
```
Topologically I would expect the result to be: `Source1, Source2, A, B,
Sink`. But instead this algorithm would produce `Source1, Source2, B, A, Sink`
because B is considered to have the higher delta than A (delta(B) = 0, delta(A)
= -1).
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Issue Time Tracking
-------------------
Worklog Id: (was: 127656)
Time Spent: 50m (was: 40m)
> Update pipeline representation in runner support libraries to handle timers
> ---------------------------------------------------------------------------
>
> Key: BEAM-4658
> URL: https://issues.apache.org/jira/browse/BEAM-4658
> Project: Beam
> Issue Type: Sub-task
> Components: runner-core
> Reporter: Luke Cwik
> Assignee: Luke Cwik
> Priority: Major
> Time Spent: 50m
> Remaining Estimate: 0h
>
> Expose relevant timer information on *ExecutableStage* to runners
> Update fusion logic to handle timers.
> Provide execution time interface to fire timers into *RemoteBundle*s and also
> to receive new timers that are being set.
>
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