#FORMAT plain hhosts(1) HADOOP hhosts(1)
NAME
hhosts - display current status of the host(s).
SYNOPSIS
hhosts [-jt trackers:trackers...] [-h]
DESCRIPTION
By default, hhosts returns the information about all hosts in the
specified cluster. This command will display the host status, task
slots and so on.
-h
Disoplay usage information.
-jt jobtracker url
specify the cluster cluster by the jobtracker's url link, for
example: -jt hostA:3479;hostB:3479
OUTPUT
By default, hhosts display the following fields:
HOST
The name of the host. If a host is currently a host of a cluster
specifed by the command, the host name will be displayed here.
STATUS
The current status of the host (In fact, the status of TaskTracker
daemon). The possilbe values for host status are as the follows.
ok
The host is available to accept new tasks.
closed
The host is not allowed to accept new tasks any more, but tasks
currently running on the host will continue until finished.
MAX
The maximum number of tasks including MAPs and Reduces that can be
run at the same time for a host. (2*cpu number is recommanded)
MAP
The number of MAP tasks currently running on the hosts.
REDUCE
The number of REDUCE tasks currently running on the hosts.
FAILURE
The number failed tasks on the host.
TMP_SPACE
The amount of free space in /tmp, in megabytes. For MAP/REDUCE jobs,
this parameter is important.
EXAMPLE
% hhosts
HOST STATUS MAX MAP REDUCE FAILURE TMP_SPACE
c0101 ok 6 6 0 0 218M
c0102 ok 6 2 4 0 568M
AUTHOR
Written by Shuguang Liu
REPORT BUGS
Report bugs to <honkliu@hotmail.com>
COPYRIGHT
Copyright (C) 2005-2010 Shuguang Liu's Inc.
This file is not a free software, all the source codes are protected
and will not be released to any body or organization without
authority.
SEE ALSO
hload(1), hopen(1), hclose(1), hslot(1)
hhosts (hadoop utils) 13.0 October 2007