SCore User Manual

a.out [-score option_string] arg1 arg2 ... argn
Here let us assume a.out is an executable file linked with SCore-S library. During the initialization of SCore-S, the command arguments are scanned, and SCore-S assumes that the argument following the keyword -score is an SCore option string. The rest of the arguments are passed to the user program, a.out.

a.out can run standalone on a hostmachine when requiring one node. It should be invoked on a host that is an element host of a workstation cluster when requiring more than one host. However, when SCore-D is running on a workstation cluster, users can invoke their programs on the host anywhere IP reachable to the cluster, if the host machine and the cluster hosts are the same machine type.

If the user program is running with SCore-S library (standalone), the program execution can be aborted by sending SIGINT (^C)to the invoked process. During the spawning procedure, SIGINT is blocked, because SCore-S may fail to spawn processes on the remote hosts. In the case of some cluster hosts is down, the signal blocking is released when there is no answer from the spawned process for more than 10 seconds. Sending SIGINT in this situation, spawned process keeps running. It is the user's responsibility to kill the singleton process. Under SCore-D, SIGINT to kill and SIGTSTP to suspend are properly handled.

Options in the option string is separated by commas (,) or blanks. When each option is separated by blanks, the entire option string must be quoted. The -score keyword and the following option string can be placed anywhere in the command arguments. Each option setting consists of keyword and value. Like shell environment variables, the keyword and associated value are separated by an equals (=) symbol character.

The option string is searched from left to right. If there are two or more options having the same keyword, the leftmost one is taken. After searching the option string, SCore tries to get the other option string from shell environment variable named SCORE_OPTIONS. If the user program is to run under SCore-D, the value of shell environment variable named SCORED_OPTIONS is also taken as an additional option string.

Effective options can vary depending on which library is linked with the executable file. In general, the communication library and language runtime library are required to be linked. Such libraries may have different options from the others. Thus, the options listed in this section is a minimum set.

SCore takes the value of shell environment variable environ as a option string. Its format is the same as the one in command argument. The option string spcified in the environment variable can contain the default option.
This option setting is replaced by the environment variable name and its value. SCore does not pass environment variables of invoked the process to the processes spawned.
The program prints option setting information, and then exits.
The program first prints the current option setting, and then starts its execution.

The pathname is a filename assumed to contain the cluster configuration. Default is score.conf.
The number of host nodes required to run the program is specified by number_of_nodes option. Note that the specified number is taken as a request, and the actual number of allocated hosts may be different.
The hostname is assumed to be SCore-D server host, and SCore-S tries to connect to the host to submit a job.

The following two options are dedicated for the cluster having Myrinet network interface.
The pathname is assumed to be a MCP filename. MCP stands for Myrinet Control Program, and is the firmware for Myrinet LANai processor that controls Myrinet interface.
In case the workstation cluster has two or more Myrinet interfaces, this option specifies which interface is to be used. The default unit number is 0.

If the debug option is specified, and the SCore-S library detects a panic situation or an exceptional signal, then SCore-S tries to invoke a GDB and let it attach to the user program. DISPLAY shell environment variable is expected to be set properly, so that xterm under which GDB runs can display a window on your host.

Environment Variables
Option string specified in the command argument is analyzed, then SCore-S tries to get option string from this shell environment variable also.
If the user program is to run under SCore-D, the value of this shell environment variable is taken as option string too.

SCore does not try to detect if any other users login and CPU consumption. If so, your program execution speed may slowdown. It is users etiquettes that you do not run a text editor or compiler on the cluster hosts if some other user is using the cluster. Use msgb to see which cluster hosts are in use, or use msgblock to lock host(s) for running non-SCore programs.


The total number of option settings is limited by maximum transmission unit of communication library.

SCore-D User Manual

Real World Computing Partnership
Parallel Distributed System Software Tsukuba Laboratory

$Id: score-user.html,v 1.12 1998/06/02 11:50:41 kameyama Exp $