@InterfaceAudience.Public @InterfaceStability.Evolving public class MultiTableSnapshotInputFormat extends TableSnapshotInputFormat implements org.apache.hadoop.mapred.InputFormat<ImmutableBytesWritable,Result>
.TableSnapshotInputFormat
allowing a MapReduce job to run over one or more table snapshots, with one or more scans
configured for each.
Internally, the input format delegates to .TableSnapshotInputFormat
and thus has the same performance advantages; see .TableSnapshotInputFormat for
more details.
Usage is similar to TableSnapshotInputFormat, with the following exception:
initMultiTableSnapshotMapperJob takes in a map
from snapshot name to a collection of scans. For each snapshot in the map, each corresponding
scan will be applied;
the overall dataset for the job is defined by the concatenation of the regions and tables
included in each snapshot/scan
pair.
TableMapReduceUtil.initMultiTableSnapshotMapperJob(Map,
Class, Class, Class, JobConf, boolean, Path)
can be used to configure the job.
Job job = new Job(conf);
Map<String, Collection<Scan>> snapshotScans = ImmutableMap.of(
"snapshot1", ImmutableList.of(new Scan(Bytes.toBytes("a"), Bytes.toBytes("b"))),
"snapshot2", ImmutableList.of(new Scan(Bytes.toBytes("1"), Bytes.toBytes("2")))
);
Path restoreDir = new Path("/tmp/snapshot_restore_dir")
TableMapReduceUtil.initTableSnapshotMapperJob(
snapshotScans, MyTableMapper.class, MyMapKeyOutput.class,
MyMapOutputValueWritable.class, job, true, restoreDir);
.TableSnapshotInputFormat
(one per region).
See TableSnapshotInputFormat for more notes on
permissioning; the
same caveats apply here.TableSnapshotInputFormat,
TableSnapshotScannerTableSnapshotInputFormat.TableSnapshotRegionSplit| Constructor and Description |
|---|
MultiTableSnapshotInputFormat() |
| Modifier and Type | Method and Description |
|---|---|
org.apache.hadoop.mapred.RecordReader<ImmutableBytesWritable,Result> |
getRecordReader(org.apache.hadoop.mapred.InputSplit split,
org.apache.hadoop.mapred.JobConf job,
org.apache.hadoop.mapred.Reporter reporter) |
org.apache.hadoop.mapred.InputSplit[] |
getSplits(org.apache.hadoop.mapred.JobConf job,
int numSplits) |
static void |
setInput(org.apache.hadoop.conf.Configuration conf,
Map<String,Collection<Scan>> snapshotScans,
org.apache.hadoop.fs.Path restoreDir)
Configure conf to read from snapshotScans, with snapshots restored to a subdirectory of
restoreDir.
|
setInput, setInputpublic org.apache.hadoop.mapred.InputSplit[] getSplits(org.apache.hadoop.mapred.JobConf job,
int numSplits)
throws IOException
getSplits in interface org.apache.hadoop.mapred.InputFormat<ImmutableBytesWritable,Result>getSplits in class TableSnapshotInputFormatIOExceptionpublic org.apache.hadoop.mapred.RecordReader<ImmutableBytesWritable,Result> getRecordReader(org.apache.hadoop.mapred.InputSplit split, org.apache.hadoop.mapred.JobConf job, org.apache.hadoop.mapred.Reporter reporter) throws IOException
getRecordReader in interface org.apache.hadoop.mapred.InputFormat<ImmutableBytesWritable,Result>getRecordReader in class TableSnapshotInputFormatIOExceptionpublic static void setInput(org.apache.hadoop.conf.Configuration conf,
Map<String,Collection<Scan>> snapshotScans,
org.apache.hadoop.fs.Path restoreDir)
throws IOException
.MultiTableSnapshotInputFormatImpl#RESTORE_DIRS_KEY,
.MultiTableSnapshotInputFormatImpl#SNAPSHOT_TO_SCANS_KEYconf - snapshotScans - restoreDir - IOExceptionCopyright © 2007–2019 The Apache Software Foundation. All rights reserved.