arrayd - array services daemon


SYNOPSIS

       arrayd [options]


DESCRIPTION

       arrayd  is the array services daemon.  It performs several
       different tasks related to the use of an array of  two  or
       more machines, such as:

        - Allocating global array session handles

        - Forwarding  "array  commands" to all of the machines in
          an array

        - Maintaining a database of the current array  configura­
          tion  and  providing that information to other commands
          and programs

        - Determining which  processes  belong  to  a  particular
          array  session  and providing that information to other
          commands and programs

For more discussion of these services, see array_services(5).

The arrayd command itself has several command line options.   The
valid options include:


-c "Check": causes arrayd to read any configuration files

       then exit immediately, sending any errors to stderr rather
       than  syslog  (which is the usual behavior).  This is pri­
       marily of use for checking the validity of new  configura­
       tion files.  This is the same as the --qqff flag.


-f filename

       Specifies  the  name of a single configuration file.  This
       option may be specified more than once, in which case  the
       files  will be processed in the order that they are speci­
       fied.  One reason to  have  multiple  configuration  files
       would be to allow all of the machines in an array to use a
       single file (accessed via NFS, perhaps) for array  entries
       and  still  maintain private configuration files for local
       options and/or security information.   The  format  of  an
       arrayd  configuration file is described in arrayd.conf(4).
       If   no   configuration   files   are   specified,    then
       "/usr/lib/array/arrayd.conf"                           and
       "/usr/lib/array/arrayd.auth" will both be  used  (in  that
       order).


-m number

       Sets  the  "machine identifier" used by the array services

       ber.   Certain  versions  of  the IRIX kernel may also use
       this value when generating array session handles.   number
       must be a value between 0 and 32767.  It will override any
       IDENT setting in the LOCAL section  of  any  configuration
       file.


-mt number

       Sets  the time interval for arrayd deamon to check whether
       any mpi job has died.  If any mpi  job  dies  arrayd  will
       clean  up the children of that mpi job.  The time interval
       is in second and it can be any number between 0 and 32767.
       The default time interval is 10 (sec).


-n Ordinarily, arrayd will automatically "daemonize" itself,

       that is, dissociate itself from the current  terminal  and
       place  itself  in  the background.  Specifying this option
       will cause arrayd to run in the foreground on the  current
       terminal.  This is mostly useful for testing purposes.


-nf Do not read any configuration files. This is most useful

       with options like --ssmm that cause arrayd to quit after per­
       forming  tasks  that do not require configuration informa­
       tion.  --nnff will override any --ff options.


-nm Do not set the system machine ID. This is used to over­

       ride a "LOCAL OPTIONS SETMACHID" statement in the configu­
       ration file.


-p number

       This specifies which port the array services daemon should
       listen on for requests.  It will override any PORT setting
       in the LOCAL section of any configuration file.


-qf Quit after parsing the configuration file(s). This is the

       same as the --cc option.


-qm Quit after setting the system machine ID. Causes arrayd

       to exit as soon as it has set the system  machine  identi­
       fier (or would have done so, in the case where this opera­
       tion is not supported by the current  OS  release).   This
       may  be useful in cases where a non-default system machine
       identifier is desired, but none of the  other  array  ser­
       vices  provided  by  arrayd  are needed.  This can also be
       used to change the machine identifier on a system that  is
       already running another copy of arrayd; in this case, ker­
       nel-generated array  session  handles  will  use  the  new
       machine  identifier  while  those generated by arrayd will
       continue to use the original machine identifier.


-sm Some versions of IRIX permit setting a system "machine

       identifier",  which  is  used by the kernel for generating
       global array session handles.  If the current  system  has
       this  facility  and  --ssmm is specified, arrayd will set the

       ment  in  the  configuration  file  or on the command line
       using the --mm option.


-v "Verbose": the daemon will run in the foreground (as with

       the -n option) and will send any error messages, plus some
       additional messages, to stderr rather than syslog.  Speci­
       fying  this  option more than once or specifying more than
       one "v" (for example "-vvv") will cause additional  debug­
       ging information to be generated.

To  clean  up  errorlog file at a specific time interval the user
needs to set  two  variables  before  running  arrayd;  they  are

ARRAYD_ELCHECK and ARRAYD_ELAGE. The ARRAYD_ELCHECK variable

defines the interval, in seconds, that arrayd uses to  check  for

files in the "/tmp/.arraysvcs" directory. The ARRAYD_ELAGE vari­

able, also in seconds, defines the interval that arrayd  uses  to
check the age of the files in the "/tmp/.arraysvcs" directory and
remove files that are too old.


The default value for ARRAYD_ELCHECK is 3600 seconds (1hr). The


default value for ARRAYD_ELAGE is 86400 seconds (24hrs).


On larger systems with 128 processors or more, this tmp directory
may not be cleared often enough, causing permission problems with
the  special  files  located therein.  In this case, it is recom­

mended that lower values for ARRAYD_ELCHECK and ARRAYD_ELAGE be

used.   For  example,  setting  these  variables  to  half of the
default values - 1800 and 43200 respectively -  will  clear  this
tmp  directory more frequently and should resolve most permission
problems of this type.

The system administrator can define these  two  variables  before
the  call  to arrayd in the "/etc/init.d/array" script, then stop
and restart arrayd.

If you want to run jobs through arrayd across  a  large  cluster,
where  there  might  be  a  lot of congestion on the network, you

might want to tune ARRAYD_CONNECTTO and ARRAYD_TIMEOUT variables.

By  default, these two variables are set to 5 seconds and 45 sec­
onds, respectively. If there is a  possible  network  congestion,
you  might  want  to  set these two variables higher than default
setting. This might slow down some array commands when a host  is
unavailable but it will help to prevent MPI start up problems due
to connection time-out.


NOTES

       arrayd can be set up to run automatically at  system  ini­
       tialization  time  by  using  the chkconfig(1M) command to
       turn on the array feature:

         cchhkkccoonnffiigg aarrrraayy oonn

       options from the file /etc/config/arrayd.options.


SEE ALSO

       array(1), arrayd.conf(4), array_services(5).


Man(1) output converted with man2html