Unable to load the HFiles into HBase using mapreduce.LoadIncrementalHFiles

Question

I want to insert the out-put of my map-reduce job into a HBase table using HBase Bulk loading API LoadIncrementalHFiles.doBulkLoad(new Path(), hTable).

I am emitting the KeyValue data type from my mapper and then using the HFileOutputFormat to prepare my HFiles using its default reducer.

When I run my map-reduce job, it gets completed without any errors and it creates the outfile, however, the final step - inserting HFiles to HBase is not happening. I get the below error after my map-reduce completes:

13/09/08 03:39:51 WARN mapreduce.LoadIncrementalHFiles: Skipping non-directory hdfs://localhost:54310/user/xx.xx/output/_SUCCESS
13/09/08 03:39:51 WARN mapreduce.LoadIncrementalHFiles: Bulk load operation did not find any files to load in directory output/.  Does it contain files in subdirectories that correspond to column family names?

But I can see the output directory containing:

1. _SUCCESS
2. _logs
3. _0/2aa96255f7f5446a8ea7f82aa2bd299e file (which contains my data)

I have no clue as to why my bulkloader is not picking the files from output directory.

Below is the code of my Map-Reduce driver class:

public static void main(String[] args) throws Exception{

    String inputFile = args[0];
    String tableName = args[1];
    String outFile = args[2];
    Path inputPath = new Path(inputFile);
    Path outPath = new Path(outFile);

    Configuration conf = new Configuration();
    FileSystem fs = FileSystem.get(conf);

    //set the configurations
    conf.set("mapred.job.tracker", "localhost:54311");

    //Input data to HTable using Map Reduce
    Job job = new Job(conf, "MapReduce - Word Frequency Count");
    job.setJarByClass(MapReduce.class);

    job.setInputFormatClass(TextInputFormat.class);

    FileInputFormat.addInputPath(job, inputPath);

    fs.delete(outPath);
    FileOutputFormat.setOutputPath(job, outPath);

    job.setMapperClass(MapReduce.MyMap.class);
    job.setMapOutputKeyClass(ImmutableBytesWritable.class);
    job.setMapOutputValueClass(KeyValue.class);

    HTable hTable = new HTable(conf, tableName.toUpperCase());

    // Auto configure partitioner and reducer
    HFileOutputFormat.configureIncrementalLoad(job, hTable);

    job.waitForCompletion(true);

    // Load generated HFiles into table
    LoadIncrementalHFiles loader = new LoadIncrementalHFiles(conf);
    loader.doBulkLoad(new Path(outFile), hTable);

}

How can I figure out the wrong thing happening here which I avoiding my data insert to HBase?

Answer 1

Finally, I figured out as to why my HFiles were not getting dumped into HBase. Below are the details:

My create statement ddl was not having any default column-name so my guess is that Phoenix created the default column-family as "_0". I was able to see this column-family in my HDFS/hbase dir.

However, when I use the HBase's LoadIncrementalHFiles API for fetching the files from my output directory, it was not picking my dir named after the col-family ("0") in my case. I debugged the LoadIncrementalHFiles API code and found that it skips all the directories from the output path that starts with "" (for e.g. "_logs").

I re-tried the same again but now by specifying some column-family and everything worked perfectly fine. I am able to query data using Phoenix SQL.