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Re: PartitionNotFoundException after deployment


Hey Gyula!

I'm including Piotr and Nico (cc'd) who have worked on the network
stack in the last releases.

Registering the network structures including the intermediate results
actually happens **before** any state is restored. I'm not sure why
this reproducibly happens when you restore state. @Nico, Piotr: any
ideas here?

In general I think what happens here is the following:
- a task requests the result of a local upstream producer, but that
one has not registered its intermediate result yet
- this should result in a retry of the request with some backoff
(controlled via the config params you mention
taskmanager.network.request-backoff.max,
taskmanager.network.request-backoff.initial)

As a first step I would set logging to DEBUG and check the TM logs for
messages like "Retriggering partition request {}:{}."

You can also check the SingleInputGate code which has the logic for
retriggering requests.

– Ufuk


On Fri, May 4, 2018 at 10:27 AM, Gyula Fóra <gyula.fora@xxxxxxxxx> wrote:
> Hi Ufuk,
>
> Do you have any quick idea what could cause this problems in flink 1.4.2?
> Seems like one operator takes too long to deploy and downstream tasks error
> out on partition not found. This only seems to happen when the job is
> restored from state and in fact that operator has some keyed and operator
> state as well.
>
> Deploying the same job from empty state works well. We tried increasing the
> taskmanager.network.request-backoff.max that didnt help.
>
> It would be great if you have some pointers where to look further, I havent
> seen this happening before.
>
> Thank you!
> Gyula
>
> The errror:
> org.apache.flink.runtime.io.network.partition.: Partition
> 4c5e9cd5dd410331103f51127996068a@b35ef4ffe25e3d17c5d6051ebe2860cd not found.
>     at
> org.apache.flink.runtime.io.network.partition.ResultPartitionManager.createSubpartitionView(ResultPartitionManager.java:77)
>     at
> org.apache.flink.runtime.io.network.partition.consumer.LocalInputChannel.requestSubpartition(LocalInputChannel.java:115)
>     at
> org.apache.flink.runtime.io.network.partition.consumer.LocalInputChannel$1.run(LocalInputChannel.java:159)
>     at java.util.TimerThread.mainLoop(Timer.java:555)
>     at java.util.TimerThread.run(Timer.java:505)



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