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]