CountTableRows
MapReduce Job Results
Whether running against a secure or non-secure store, as the job runs, assuming no errors, the output from the job will look like the following:
...
INFO [main] mapreduce.Job (Job.java:monitorAndPrintJob(1344))
- Running job: job_1409172332346_0024
INFO [main] mapreduce.Job (Job.java:monitorAndPrintJob(1372))
- map 0% reduce 0% INFO [main] mapreduce.Job
(Job.java:monitorAndPrintJob(1372))
- map 26% reduce 0%
INFO [main] mapreduce.Job (Job.java:monitorAndPrintJob(1372))
- map 56% reduce 0%
INFO [main] mapreduce.Job (Job.java:monitorAndPrintJob(1372))
- map 100% reduce 0% INFO [main] mapreduce.Job
(Job.java:monitorAndPrintJob(1383))
- Job job_1409172332346_0024 completed successfully
INFO [main] mapreduce.Job (Job.java:monitorAndPrintJob(1390))
- Counters: 49
File System Counters
FILE: Number of bytes read=2771
FILE: Number of bytes written=644463
FILE: Number of read operations=0
FILE: Number of large read operations=0
FILE: Number of write operations=0
HDFS: Number of bytes read=2660
HDFS: Number of bytes written=32
HDFS: Number of read operations=15
HDFS: Number of large read operations=0
HDFS: Number of write operations=2
Job Counters
Launched map tasks=6
Launched reduce tasks=1
Rack-local map tasks=6
Total time spent by all maps in occupied slots (ms)=136868
Total time spent by all reduces in occupied slots (ms)=2103
Total time spent by all map tasks (ms)=136868
Total time spent by all reduce tasks (ms)=2103
Total vcore-seconds taken by all map tasks=136868
Total vcore-seconds taken by all reduce tasks=2103
Total megabyte-seconds taken by all map tasks=140152832
Total megabyte-seconds taken by all reduce tasks=2153472
Map-Reduce Framework
Map input records=79
Map output bytes=2607
Map output materialized bytes=2801
Input split bytes=2660
Combine input records=0
Combine output records=0
Reduce input groups=1
Reduce shuffle bytes=2801
Reduce input records=79
Reduce output records=1
Spilled Records=158
Shuffled Maps =6
Failed Shuffles=0
Merged Map outputs=6
GC time elapsed (ms)=549
CPU time spent (ms)=9460
Physical memory (bytes) snapshot=1888358400
Virtual memory (bytes) snapshot=6424895488
Total committed heap usage (bytes)=1409286144
Shuffle Errors
BAD_ID=0
CONNECTION=0
IO_ERROR=0
WRONG_LENGTH=0
WRONG_MAP=0
WRONG_REDUCE=0
File Input Format Counters
Bytes Read=0
File Output Format Counters
Bytes Written=32
To see the results of the job and to verify that the program counted the correct number of rows in the table, use the Hadoop CLI to display the contents of the MapReduce results file located in HDFS. To do this, type the following at the command line of the Hadoop cluster's access node:
hadoop fs -cat \
/user/example-user/CountTableRows/vehicleTable/<000N>/part-r-00000
where the <000N>
token should be replaced with the value you used when the job was run. Assuming the table was populated with 79 rows, if the job was successful, then the output should look like the following:
/type/make/model/class 79
where /type/make/model/class
are the names of the fields making up the PrimaryKey of the vehicleTable
, and 79 is the number of rows in the table.