Show the Hosts/Taskers

The command nc hosts shows the list of the hardware resources currently connected to an instance of Accelerator. These hardware resources are called "taskers" in Accelerator.


nc: Usage Message

NC HOSTS
    Show taskers that are currently in the cluster along with tasker metadata.

    The default output includes:
    NAME LOAD STATUS RUN/SUSP SLOTS HEARTBEAT RESERVATIONS MESSAGE

    Each tasker takes on the name of its host by default.

    The "RUN/SUSP" column shows running jobs and suspended jobs,
    respectively.

    The "SLOTS" column shows total job slots.

    The heartbeat is the age of the most recent heartbeat received by the
    vovserver for that specific tasker.

    The reservations column shows shorthand representations for who or what
    the tasker is reserved and the time remaining for the reservation. The
    shorthand format is TYPE:NAME, where TYPE is one of:
    G (group), I (ID), B (bucket), C (jobclass), P (project), or U (user).

USAGE:
    % nc hosts [OPTIONS]

OPTIONS:
    -h              -- This help
    -c              -- Show consumable resources (e.g. RAM and CPUs)
    -f              -- Show list of tasker fields
    -r              -- Show status and resources for each tasker
    -rl             -- Show resources (legacy: pre-2013.03 format)
    -m              -- Show machine parameters (RAM, CPUfreq, ...)
    -a              -- Show all known hosts (used with -m)
    -hw <HW>        -- Show only taskers that match HW constraints.
    -rule <SELRULE> -- Show only taskers that match the given selection rule.
                       Use "vovselect fieldname from taskers" for the complete
                       list of fields that can be used in the rule.
                       Example rules:
                            "status==READY"
                            "status!=OVRLD slots>8"
                       Can accept multiple constraints.
    -O <fmt>        -- Specify output format. The format string can contain
                       elements like @FIELDNAME@ or @FIELDNAME:WIDTH@ where
                       a negative width means left-align and a positive width
                       means right-align.
    -RAM            -- Same as -O "@NAME@ RAM/@RAM@ RAMFREE#@RAMFREE@
                                   RAMTOTAL#@RAMTOTAL@"
    -SLOTS          -- Same as -O "@NAME@ SLOTS/@SLOTS@ SLOTSTOTAL#@SLOTSTOTAL@
                                   CORES/@CORES@ CORESTOTAL#@CORESTOTAL@"
    -LOAD           -- Same as -O ...selection of fields about load...
    -INFO           -- Same as -O ...fields about host, arch, model, ...
    -ALL            -- Show resources for each tasker
    -slowdown       -- Used only for testing

EXAMPLES:
    % nc hosts
    % nc hosts -m
    % nc hosts -a -m
    % nc hosts -hw 'RAMTOTAL>18000'
    % nc hosts -f
    % nc hosts -O "RAMFREE#@RAMFREE@ SWAP/@SWAP@ M=@MODEL@"
    % nc hosts -O "@I:4@ @NAME:-14@ @STATUS:-8@ @HOST@ "
    % nc hosts -RAM
    % nc hosts -hw 'RAMTOTAL>18000' -RAM
    % nc hosts -ALL | grep -A8 ^lnx001
    % nc hosts -rule "cores>4 ramtotal<20000" -O "@name@ @corestotal@"
    
An example is shown below:
% nc hosts
# TASKER        LOAD STATUS   JOBS  MESSAGE
1 alpaca       0.01 ready    0/1   Workstation idle
2 bison        0.07 ready    0/1   Workstation idle
3 blue-srv     0.15 ready    0/1   
4 cayman       0.00 susp     0/1   Off hour tasker (will start at 19:00)
5 cheetah      0.00 ready    0/1   Workstation idle
6 comet-srv    0.23 ready    0/1   
7 everett      0.00 ready    0/2   
8 jupiter-srv  0.07 ready    0/2   
9 mars-srv     0.06 ready    0/2   
10 moon-srv     0.09 ready    0/1   

% nc hosts -r
...
% nc hosts -m
...

Use vovselect for Querying

The nc hosts command can be used for querying, but it can sometimes take several minutes to return results, which causes some nodes to show up as "N/A". nc hosts will query the server and return significant amounts of data, but the server loading will directly affect the response time of the command.

In order to avoid such delay, you can use vovselect to run the query, as it prefilters the output server-side before returning it to the client.

Use the table below to understand the mapping of fields between the nc hosts and vovselect commands.

nc hosts vovselect from TASKERS vovselect from HOSTS
ARCH ARCH ARCH
CAPABILITIES CAPABILITIES NA
CAPACITY CAPACITY CPUS
CLASSRESOURCES CLASSRESOURCES NA
CLOCK CLOCK CPUCLOCK
COEFF COEFF NA
CONSUMABLES CONSUMABLES NA
CORES CORESAVAIL NA
CORESAVAIL CORESAVAIL NA
CORESTOTAL CORESTOTAL CPUS
CORESUSED CORESUSED NA
CPUS CPUS CPUS
CURLOAD CURLOAD NA
DOEXEC DOEXEC NA
DONETINFO DONETINFO NA
DOPROCINFO DOPROCINFO NA
DORTTRACING DORTTRACING NA
EFFLOAD NA NA
EXTRAS EXTRAS NA
FULLINFO FULLINFO NA
GROUP GROUP NA
HB NA NA
HBPP NA NA
HEARTBEAT HEARTBEAT NA
HOST HOST NAME
ID ID NA
IDINT IDINT NA
LASTJOBID NA NA
LASTUPDATE LASTUPDATE NA
LIFETIMEJOBS LIFETIMEJOBS NA
LOAD1 NA NA
LOAD15 NA NA
LOAD5 NA NA
LOADEFF NA NA
MACHINE MACHINE MACHINE
MANUALPOWER NA NA
MAXLOAD MAXLOAD NA
MESSAGE MESSAGE NA
MESSAGESYS MESSAGESYS NA
MESSAGEUSER MESSAGEUSER NA
MODEL MODEL NA
NAME NAME NAME
NUMJOBS NA NA
OSCLASS OSCLASS NA
PERCENT PERCENT NA
PERSISTENT PERSISTENT NA
PID PID NA
POWER POWER NA
RAM RAM NA
RAMFREE RAMFREE NA
RAMTOTAL RAMTOTAL RAMTOTAL
RAWPOWER NA NA
RELEASE RELEASE NA
RESERVEDBY RESERVEDBY NA
RESERVEEND RESERVEEND NA
RESERVEFORBUCKETID RESERVEFORBUCKETID NA
RESERVEFORID RESERVEFORID NA
RESERVEGROUP RESERVEGROUP NA
RESERVEJOBCLASS RESERVEJOBCLASS NA
RESERVEJOBPROJ RESERVEJOBPROJ NA
RESERVEOSGROUP RESERVEOSGROUP NA
RESERVESTART RESERVESTART NA
RESERVEUSER RESERVEUSER NA
RESOURCECMD RESOURCECMD NA
RESOURCES NA NA
RESOURCESEXTRA NA NA
RESOURCESPEC RESOURCESPEC NA
RUNNINGJOBS RUNNINGJOBS NA
SLOTS NA NA
SLOTSTOTAL SLOTSTOTAL NA
STATSREJECTCORES STATSREJECTCORES NA
STATSREJECTOTHER STATSREJECTOTHER NA
STATSREJECTRAM STATSREJECTRAM NA
STATSREJECTRESERVED STATSREJECTRESERVED NA
STATSREJECTSLOTS STATSREJECTSLOTS NA
STATSVISITS NA NA
STATUS NA NA
SWAP SWAP NA
SWAPFREE SWAPFREE NA
SWAPTOTAL SWAPTOTAL NA
TASKERGROUP TASKER NA
TASKERNAME TASKERNAME NAME
TASKERSLOTSSUSPENDABLE TASKERSLOTSSUSPENDABLE NA
TASKERSLOTSSUSPENDED TASKERSLOTSSUSPENDED NA
TASKERSLOTSUSED TASKERSLOTSUSED NA
TASKERTYPE TASKERTYPE NA
TIMELEFT TIMELEFT NA
TMP TMP NA
TYPE TYPE NA
UPTIME NA NA
UPTIMEPP UPTIMEPP NA
USER USER NA
VERSION VERSION NA
VOVVERSION VOVVERSION NA