Styx Grid Services Tutorial: Getting help

You can get help and usage information for any Styx Grid Service from the SGSRun program. Just typing SGSRun on its own will reveal a usage message that shows that SGSRun expects at least three arguments: the host name and port number of the remote server and the name of the Styx Grid Service itself.

Brief usage information

If you want to see the usage information (i.e. the expected command-line arguments) for a particular SGS, use the --sgs-help command-line switch. For example, to get usage information for the reverse2 SGS that we created earlier in the tutorial, enter:

SGSRun localhost 9092 reverse2 --sgs-help

This will print out (to standard output) the description of the SGS (taken directly from the server's configuration file) and a brief usage message describing the command-line arguments. The above example will print out the following information:

Reads lines of input and outputs them with characters reversed

Usage: reverse2 -i <inputfile> -o <outputfile> [--sgs-help] [--sgs-verbose-help]
    [--sgs-debug] [--sgs-allrefs] [--sgs-lifetime <sgs-lifetime>]

Mandatory arguments are given in angle brackets (< >) and optional arguments are given in square brackets ([ ]). Note that, in addition to the the arguments that are expected by the reverse2 program, there are a number of optional arguments whose names begin with --sgs-. There arguments are available for all Styx Grid Services.

Verbose usage information

More details on the usage of a particular SGS can be found with the --sgs-verbose-help switch. For example, running SGSRun locahost 9092 reverse2 --sgs-verbose-help will print out the following to the console window:

Reads lines of input and outputs them with characters reversed

Usage: reverse2 -i <inputfile> -o <outputfile> [--sgs-help] [--sgs-verbose-help]
    [--sgs-debug] [--sgs-allrefs] [--sgs-lifetime <sgs-lifetime>]

  -i <inputfile>
        Name of input file

  -o <outputfile>
        Name of output file

  [--sgs-help]
        Set this switch to print out a short help message

  [--sgs-verbose-help]
        Set this switch to print out a long help message

  [--sgs-debug]
        Set this switch in order to enable printing of debug messages

  [--sgs-allrefs]
        Set this switch in order to get URLs to all output files rather than
        actual files

  [--sgs-lifetime <sgs-lifetime>]
        The lifetime of the SGS in minutes (default: 60)

As you can see, this gives a brief description of all the possible input parameters (these descriptions are taken from the server's configuration file). The meanings of the --sgs- parameters will be described later in this tutorial.

Troubleshooting

If a Styx Grid Service is not behaving as you think it should, try running it with the --sgs-debug switch. This will print out some debugging information that might lead you to the source of the problem. Even if you can't fix it yourself, this will be useful information that you can use to ask for help from the mailing lists. In general, these mailing lists are the best place to go for help as your mail will reach many users and developers of the SGS software.