Examples with CopyFrameBlockFunction org.apache.sysml.runtime.instructions.spark.functions.CopyFrameBlockFunction used on opensource projects

Example 1 with CopyFrameBlockFunction

use of org.apache.sysml.runtime.instructions.spark.functions.CopyFrameBlockFunction in project incubator-systemml by apache.

the class CheckpointSPInstruction method processInstruction.

@Override
@SuppressWarnings("unchecked")
public void processInstruction(ExecutionContext ec) throws DMLRuntimeException {
    SparkExecutionContext sec = (SparkExecutionContext) ec;
    // this is valid if relevant branches are never entered)
    if (sec.getVariable(input1.getName()) == null || sec.getVariable(input1.getName()) instanceof BooleanObject) {
        //add a dummy entry to the input, which will be immediately overwritten by the null output.
        sec.setVariable(input1.getName(), new BooleanObject(false));
        sec.setVariable(output.getName(), new BooleanObject(false));
        return;
    }
    //get input rdd handle (for matrix or frame)
    JavaPairRDD<?, ?> in = sec.getRDDHandleForVariable(input1.getName(), InputInfo.BinaryBlockInputInfo);
    MatrixCharacteristics mcIn = sec.getMatrixCharacteristics(input1.getName());
    // Step 2: Checkpoint given rdd (only if currently in different storage level to prevent redundancy)
    // -------
    // Note that persist is an transformation which will be triggered on-demand with the next rdd operations
    // This prevents unnecessary overhead if the dataset is only consumed by cp operations.
    JavaPairRDD<?, ?> out = null;
    if (!in.getStorageLevel().equals(_level)) {
        //(trigger coalesce if intended number of partitions exceeded by 20%
        //and not hash partitioned to avoid losing the existing partitioner)
        int numPartitions = SparkUtils.getNumPreferredPartitions(mcIn, in);
        boolean coalesce = (1.2 * numPartitions < in.getNumPartitions() && !SparkUtils.isHashPartitioned(in));
        //checkpoint pre-processing rdd operations
        if (coalesce) {
            //merge partitions without shuffle if too many partitions
            out = in.coalesce(numPartitions);
        } else {
            //apply a narrow shallow copy to allow for short-circuit collects 
            if (input1.getDataType() == DataType.MATRIX)
                out = SparkUtils.copyBinaryBlockMatrix((JavaPairRDD<MatrixIndexes, MatrixBlock>) in, false);
            else if (input1.getDataType() == DataType.FRAME)
                out = ((JavaPairRDD<Long, FrameBlock>) in).mapValues(new CopyFrameBlockFunction(false));
        }
        //convert mcsr into memory-efficient csr if potentially sparse
        if (input1.getDataType() == DataType.MATRIX && OptimizerUtils.checkSparseBlockCSRConversion(mcIn) && !_level.equals(Checkpoint.SER_STORAGE_LEVEL)) {
            out = ((JavaPairRDD<MatrixIndexes, MatrixBlock>) out).mapValues(new CreateSparseBlockFunction(SparseBlock.Type.CSR));
        }
        //actual checkpoint into given storage level
        out = out.persist(_level);
    } else {
        //pass-through
        out = in;
    }
    // Step 3: In-place update of input matrix/frame rdd handle and set as output
    // -------
    // We use this in-place approach for two reasons. First, it is correct because our checkpoint 
    // injection rewrites guarantee that after checkpoint instructions there are no consumers on the 
    // given input. Second, it is beneficial because otherwise we need to pass in-memory objects and
    // filenames to the new matrix object in order to prevent repeated reads from hdfs and unnecessary
    // caching and subsequent collects. Note that in-place update requires us to explicitly handle
    // lineage information in order to prevent cycles on cleanup. 
    CacheableData<?> cd = sec.getCacheableData(input1.getName());
    if (out != in) {
        //prevent unnecessary lineage info
        //guaranteed to exist (see above)
        RDDObject inro = cd.getRDDHandle();
        //create new rdd object
        RDDObject outro = new RDDObject(out, output.getName());
        //mark as checkpointed
        outro.setCheckpointRDD(true);
        //keep lineage to prevent cycles on cleanup
        outro.addLineageChild(inro);
        cd.setRDDHandle(outro);
    }
    sec.setVariable(output.getName(), cd);
}