apache beam bigtable Iterable mutation

Question

I'm migrating my google dataflow java 1.9 to beam 2.0 and I'm trying to use the BigtableIO.Write

    ....
.apply("", BigtableIO.write()
                .withBigtableOptions(bigtableOptions)
                .withTableId("twoSecondVitals"));

In the ParDo before the BigtableIO I'm struggling trying to make the Iterable.

          try{
        Mutation mutation = Mutation.parseFrom(new ObjectMapper().writeValueAsBytes(v));
        Mutation mu[] = {mutation};
        Iterable<Mutation> imu = Arrays.asList(mu);
        log.severe("imu");
        c.output(KV.of(ByteString.copyFromUtf8(rowKey+"_"+v.getEpoch()), imu));
      }catch (Exception e){
        log.severe(rowKey+"_"+v.getEpoch()+" error:"+e.getMessage());
      }

The code above throws the following exception InvalidProtocolBufferException: Protocol message end-group tag did not match expected tag

v is a list of objects (Vitals.class). The hbase api uses Put method to create the mutation. How does one create a BigTable mutation that will work with the BigtableIO sink?

Answer 1

By looking through the sdk's tests I was able to find my answer.

            Iterable<Mutation> mutations =
                ImmutableList.of(Mutation.newBuilder()
                .setSetCell(
                        Mutation.SetCell.newBuilder()
                        .setValue(ByteString.copyFrom(new ObjectMapper().writeValueAsBytes(v)))
                        .setFamilyName("vitals")
                ).build());