hadoop 动态调整mapred参数

bin/hadoop job -set-reduce-capacity job_20151126032920_1142443 1000        调成map数
bin/hadoop job -set-priority job_20151126032920_1160549 VERY_HIGH          调整优先级
bin/hadoop job -set-map-capacity job_20151126032920_1142443 1000



--------------------------------------：$ bin/hadoop job                                                  
Usage: JobClient <command> <args>
        [-submit <job-file>]
        [-status <job-id>]
        [-info <job-id>]
        [-counter <job-id> <group-name> <counter-name>]
        [-kill <job-id>]
        [-abort <job-id>]
        [-suspend <job-id> [hours]]
        [-recover <job-id> [-force] [-jobconf name=value] [-file local-path] [-cacheArchive] [-cacheFile]]
        [-set-priority <job-id> <priority>]. Valid values for priorities are: VERY_HIGH HIGH NORMAL LOW VERY_LOW
        [-set-map-capacity <job-id> <map-capacity> [ <vertex-id> ] ]
        [-set-reduce-capacity <job-id> <reduce-capacity> [ <vertex-id> ] ]
        [-set-map-over-capacity <job-id> <true/false> [ <vertex-id> ] ]
        [-set-reduce-over-capacity <job-id> <true/false> [ <vertex-id> ] ]
        [-events <job-id> <from-event-#> <#-of-events>]
        [-history <jobOutputDir>]
        [-list [all]]
        [-kill-task <task-id>]
        [-fail-task <task-id>]
        [-schedule-task <task-id>]
        [-input-add <job-id> <input>  [ <vertex-id> ] ]
        [-input-done <job-id>  [ <vertex-id> ] ]
        [-reload-limit-conf] 
        [-idle-failover <job-id>] 
Generic options supported are
-conf <configuration file>     specify an application configuration file
-D <property=value>            use value for given property
-fs <local|namenode:port>      specify a namenode
-jt <local|jobtracker:port>    specify a job tracker
-files <comma separated list of files>    specify comma separated files to be copied to the map reduce cluster
-libjars <comma separated list of jars>    specify comma separated jar files to include in the classpath.
-archives <comma separated list of archives>    specify comma separated archives to be unarchived on the compute machines.

The general command line syntax is
bin/hadoop command [genericOptions] [commandOptions]