Re: Migrate custom partitioner from Flink 1.7 to Flink 1.9

Posted by Chesnay Schepler on
URL: http://deprecated-apache-flink-user-mailing-list-archive.369.s1.nabble.com/Migrate-custom-partitioner-from-Flink-1-7-to-Flink-1-9-tp31839p31919.html

You should be able to implement this on the DataStream API level using
DataStream#broadcast and #union like this:

input = ...

singleChannel = input.filter(x -> !x.isBroadCastPartitioning);

broadcastChannel = input.filter(x -> x.isBroadCastPartitioning);

result = broadcastChannel.broadcast().union(singleChannel)

// apply operations on result


On 26/12/2019 08:20, Salva Alcántara wrote:

> I am trying to migrate a custom dynamic partitioner from Flink 1.7 to Flink
> 1.9. The original partitioner implemented the `selectChannels` method within
> the `StreamPartitioner` interface like this:
>
> ```java
>      // Original: working for Flink 1.7
>      //@Override
>      public int[] selectChannels(SerializationDelegate<StreamRecord&lt;T>>
> streamRecordSerializationDelegate,
>                                  int numberOfOutputChannels) {
>          T value =
> streamRecordSerializationDelegate.getInstance().getValue();
>          if (value.f0.isBroadCastPartitioning()) {
>              // send to all channels
>              int[] channels = new int[numberOfOutputChannels];
>              for (int i = 0; i < numberOfOutputChannels; ++i) {
>                  channels[i] = i;
>              }
>              return channels;
>          } else if (value.f0.getPartitionKey() == -1) {
>              // random partition
>              returnChannels[0] = random.nextInt(numberOfOutputChannels);
>          } else {
>              returnChannels[0] =
> partitioner.partition(value.f0.getPartitionKey(), numberOfOutputChannels);
>          }
>          return returnChannels;
>      }
>
> ```
>
> I am not sure how to migrate this to Flink 1.9, since the
> `StreamPartitioner` interface has changed as illustrated below:
>
>
> ```java
>      // New: required by Flink 1.9
>      @Override
>      public int selectChannel(SerializationDelegate<StreamRecord&lt;T>>
> streamRecordSerializationDelegate) {
>          T value =
> streamRecordSerializationDelegate.getInstance().getValue();
>          if (value.f0.isBroadCastPartitioning()) {
>              /*
>              It is illegal to call this method for broadcast channel
> selectors and this method can remain not
>              implemented in that case (for example by throwing
> UnsupportedOperationException).
>              */
>          } else if (value.f0.getPartitionKey() == -1) {
>              // random partition
>              returnChannels[0] = random.nextInt(numberOfChannels);
>          } else {
>              returnChannels[0] =
> partitioner.partition(value.f0.getPartitionKey(), numberOfChannels);
>          }
>          //return returnChannels;
>          return returnChannels[0];
>      }
> ```
>
> Note that `selectChannels` has been replaced with `selectChannel`. So, it is
> no longer possible to return multiple output channels as originally done
> above for the case of broadcasted elements. As a matter of fact,
> `selectChannel` should not be invoked for this particular case. Any thoughts
> on how to tackle this?
>
>
>
>
>
> --
> Sent from: http://apache-flink-user-mailing-list-archive.2336050.n4.nabble.com/
>