title: hive job not making progress due to Number of reduce tasks is set to 0 since there's no reduce operator
body: <p><br>
  I'm using Cloudera distribution and Hive's 13th version on my cluster.<br></p>
  
  <p>I came across a problem where job is not making any progress after writing log line - "<strong>Number of reduce tasks is set to 0 since there's no reduce operator</strong>"</p>
  
  <p><strong>Below is the log for the same, could you help me what kind of issue is this because this is not a code issue as if i re-run the same job it completes successfully.</strong></p>
  
  <pre><code>Logging initialized using configuration in jar:file:/opt/cloudera/parcels/CDH-5.2.1-1.cdh5.2.1.p0.12/jars/hive-common-0.13.1-cdh5.2.1.jar!/hive-log4j.properties
  Total jobs = 5
  Launching Job 1 out of 5
  Launching Job 2 out of 5
  Number of reduce tasks not specified. Defaulting to jobconf value of: 10
  In order to change the average load for a reducer (in bytes):
    set hive.exec.reducers.bytes.per.reducer=&lt;number&gt;
  In order to limit the maximum number of reducers:
    set hive.exec.reducers.max=&lt;number&gt;
  In order to set a constant number of reducers:
  Number of reduce tasks not specified. Defaulting to jobconf value of: 10
    set mapreduce.job.reduces=&lt;number&gt;
  In order to change the average load for a reducer (in bytes):
    set hive.exec.reducers.bytes.per.reducer=&lt;number&gt;
  In order to limit the maximum number of reducers:
    set hive.exec.reducers.max=&lt;number&gt;
  In order to set a constant number of reducers:
    set mapreduce.job.reduces=&lt;number&gt;
  Starting Job = job_1431159077692_1399, Tracking URL = xyz.com:8088/proxy/application_1431159077692_1399/
  Starting Job = job_1431159077692_1398, Tracking URL = hxyz.com:8088/proxy/application_1431159077692_1398/
  Kill Command = /opt/cloudera/parcels/CDH-5.2.1-1.cdh5.2.1.p0.12/lib/hadoop/bin/hadoop job  -kill job_1431159077692_1399
  Kill Command = /opt/cloudera/parcels/CDH-5.2.1-1.cdh5.2.1.p0.12/lib/hadoop/bin/hadoop job  -kill job_1431159077692_1398
  Hadoop job information for Stage-12: number of mappers: 5; number of reducers: 10
  Hadoop job information for Stage-1: number of mappers: 5; number of reducers: 10
  2015-05-12 19:59:12,298 Stage-1 map = 0%,  reduce = 0%
  2015-05-12 19:59:12,298 Stage-12 map = 0%,  reduce = 0%
  2015-05-12 19:59:20,832 Stage-1 map = 20%,  reduce = 0%, Cumulative CPU 2.5 sec
  2015-05-12 19:59:20,832 Stage-12 map = 80%,  reduce = 0%, Cumulative CPU 8.63 sec
  2015-05-12 19:59:21,905 Stage-1 map = 60%,  reduce = 0%, Cumulative CPU 7.06 sec
  2015-05-12 19:59:22,968 Stage-1 map = 80%,  reduce = 0%, Cumulative CPU 9.34 sec
  2015-05-12 19:59:24,031 Stage-1 map = 100%,  reduce = 0%, Cumulative CPU 11.46 sec
  2015-05-12 19:59:26,265 Stage-12 map = 100%,  reduce = 0%, Cumulative CPU 10.92 sec
  2015-05-12 19:59:32,665 Stage-12 map = 100%,  reduce = 30%, Cumulative CPU 24.51 sec
  2015-05-12 19:59:33,726 Stage-12 map = 100%,  reduce = 100%, Cumulative CPU 57.61 sec
  2015-05-12 19:59:35,021 Stage-1 map = 100%,  reduce = 30%, Cumulative CPU 20.99 sec
  MapReduce Total cumulative CPU time: 57 seconds 610 msec
  Ended Job = job_1431159077692_1399
  2015-05-12 19:59:36,084 Stage-1 map = 100%,  reduce = 80%, Cumulative CPU 39.24 sec
  2015-05-12 19:59:37,146 Stage-1 map = 100%,  reduce = 90%, Cumulative CPU 42.37 sec
  2015-05-12 19:59:38,203 Stage-1 map = 100%,  reduce = 100%, Cumulative CPU 45.97 sec
  MapReduce Total cumulative CPU time: 45 seconds 970 msec
  Ended Job = job_1431159077692_1398
  2015-05-12 19:59:45,180 WARN  [main] conf.Configuration (Configuration.java:loadProperty(2510)) - file:/tmp/srv-hdp-mkt-d/hive_2015-05-12_19-58-53_081_2145723752519383568-1/-local-10014/jobconf.xml:an attempt to override final parameter: hadoop.ssl.require.client.cert;  Ignoring.
  2015-05-12 19:59:45,193 WARN  [main] conf.Configuration (Configuration.java:loadProperty(2510)) - file:/tmp/srv-hdp-mkt-d/hive_2015-05-12_19-58-53_081_2145723752519383568-1/-local-10014/jobconf.xml:an attempt to override final parameter: mapreduce.job.end-notification.max.retry.interval;  Ignoring.
  2015-05-12 19:59:45,196 WARN  [main] conf.Configuration (Configuration.java:loadProperty(2510)) - file:/tmp/srv-hdp-mkt-d/hive_2015-05-12_19-58-53_081_2145723752519383568-1/-local-10014/jobconf.xml:an attempt to override final parameter: hadoop.ssl.client.conf;  Ignoring.
  2015-05-12 19:59:45,201 WARN  [main] conf.Configuration (Configuration.java:loadProperty(2510)) - file:/tmp/srv-hdp-mkt-d/hive_2015-05-12_19-58-53_081_2145723752519383568-1/-local-10014/jobconf.xml:an attempt to override final parameter: hadoop.ssl.keystores.factory.class;  Ignoring.
  2015-05-12 19:59:45,210 WARN  [main] conf.Configuration (Configuration.java:loadProperty(2510)) - file:/tmp/srv-hdp-mkt-d/hive_2015-05-12_19-58-53_081_2145723752519383568-1/-local-10014/jobconf.xml:an attempt to override final parameter: hadoop.ssl.server.conf;  Ignoring.
  2015-05-12 19:59:45,258 WARN  [main] conf.Configuration (Configuration.java:loadProperty(2510)) - file:/tmp/srv-hdp-mkt-d/hive_2015-05-12_19-58-53_081_2145723752519383568-1/-local-10014/jobconf.xml:an attempt to override final parameter: mapreduce.job.end-notification.max.attempts;  Ignoring.
  2015-05-12 19:59:45,792 WARN  [main] conf.HiveConf (HiveConf.java:initialize(1491)) - DEPRECATED: Configuration property hive.metastore.local no longer has any effect. Make sure to provide a valid value for hive.metastore.uris if you are connecting to a remote metastore.
  Execution log at: /tmp/srv-hdp-mkt-d/srv-hdp-mkt-d_20150512195858_1b598453-78a8-4867-9402-d972e3c067f2.log
  2015-05-12 07:59:46    Starting to launch local task to process map join;    maximum memory = 257949696
  2015-05-12 07:59:47    Dump the side-table into file: file:/tmp/srv-hdp-mkt-d/hive_2015-05-12_19-58-53_081_2145723752519383568-1/-local-10007/HashTable-Stage-4/MapJoin-mapfile10--.hashtable
  2015-05-12 07:59:47    Uploaded 1 File to: file:/tmp/srv-hdp-mkt-d/hive_2015-05-12_19-58-53_081_2145723752519383568-1/-local-10007/HashTable-Stage-4/MapJoin-mapfile10--.hashtable (475 bytes)
  2015-05-12 07:59:47    Dump the side-table into file: file:/tmp/srv-hdp-mkt-d/hive_2015-05-12_19-58-53_081_2145723752519383568-1/-local-10007/HashTable-Stage-4/MapJoin-mapfile01--.hashtable
  2015-05-12 07:59:47    Uploaded 1 File to: file:/tmp/srv-hdp-mkt-d/hive_2015-05-12_19-58-53_081_2145723752519383568-1/-local-10007/HashTable-Stage-4/MapJoin-mapfile01--.hashtable (388 bytes)
  2015-05-12 07:59:47    End of local task; Time Taken: 1.209 sec.
  Execution completed successfully
  MapredLocal task succeeded
  Launching Job 3 out of 5
  Number of reduce tasks is set to 0 since there's no reduce operator
  </code></pre>