DataScope Query Form

National Virtual Observatory DataScope

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National Virtual Observatory --- Hosted at NASA/HEASARC

VO DataScope installation

The VO DataScope comprises Perl scripts, HTML documentation, Java libraries and associated files. This document discusses the installation of this tool.

Overview

There are four major areas that are populated by the DataScope.

The CGI area is used to store the actual DataScope scripts. These are:
- init.pl: Start a DataScope session.
- datascope.pl: The datascope summary page.
- process.pl: Process a single resource or start analysis
- meta.pl: Display registry metadata
- cacheTee.pl: Retreive, store, and display a file.
- ql.pl: Create a quicklook image from a FITS file
A Web documents area includes the DataScope help.
The Perl library area is used to store the Perl libraries used in the DataScope. Most of these libraries are subpackages of the VO package, but a few additional libraries are included. These libraries could be installed as part of a Perl installation but are normally expected to be included in a separate library area and included in Perl scripts using a use lib statement.
The cache area is an area where results from queries to outside resources are to be stored. The cache area must be writable by CGI processes, files in the cache area must be accessible as URLs.

DataScope assumes a version of Perl which has XML and SOAP parsers installed. The following loaded necessary modules starting from a fresh installation of Perl 5.8.5.

The XML::Parser module was loaded. If the EXPAT library and include files are not in standard system directories this may need to be done manually. I.e., the CPAN distribution is downloaded and unpacked, and the make files are created using the
command perl Makefile.PL EXPATLIBPATH=xxx EXPATINCPATH=yyy
where xxx is the directory containing the EXPAT library and yyy is the directory containing the expat.h include file.
The module URI was installed using the CPAN module for installation. E.g.,
```
     > perl -MCPAN -e shell
     install URI
     
```
The CPAN module must be initialized the first time it is used in a Perl installation.
The module SOAP::Lite was installed manually using the 0.65b2 version available at www.soaplite.com.
The Archive::Tar module was installed using CPAN.
The Bundle::Libnet was installed using CPAN
The LWP::UserAgent was installed using CPAN.
The XML::DOM was installed using CPAN; the installation may need to be forced to get past some test errors, i.e., force install XML::DOM
The XML::DOM::ValParser was installed using CPAN; the installation may need to be forced.


  Note that there are some errors may be encountered in loading XML parsing modules.  These
  seem to occur due to incompatibilities between SAX and DOM parsers and do not seem
  to recur when the modules are used within DataScope.
  
  
   Installation procedures 
  
  Download the datascope.nn.tar.gz file from a DataScope repository
  and untar the file.  The installDataScope.pl
  command will be found in the top directory.
  
  
  The installDataScope.pl command does a number of the tasks required
  for installing the DataScope.  It queries for the root locations for
  the four areas described above, changes the first line in the
  Perl scripts to use the version of Perl it is invoked under, and modifies
  several the VO/Util.pm file to use the given locations.
  It is assumed that the user of the command has write privileges to
  the CGI, documents and library areas.
  

  A typical installation using installDataScope.pl looks like the following where
  the user input is in bold.
  
  

  
  
  > perl installDataScope.pl

Welcome to the DataScope installation script.
Full Perl executable path [/usr/local/web_chroot/skyview3/test/bin/perl]: /skyview3/test/bin/perl
File location for VO CGI scripts [/www/htdocs/cgi-bin/vo]: /skyview/htdocs/cgi-bin/test/vo
URL root of VO CGI URLs [/cgi-bin/vo]: /cgi-bin/test/vo
File location for VO HTML documents [/www/htdocs/vo]: /skyview/htdocs/test/vo
URL root of VO documents [/vo]: /test/vo
Root for VO Perl libraries [/usr/local/vo/lib]: /skyview3/local/lib
Root for query cache [/www/htdocs/vo/newcache]: /skyview/htdocs/tempspace/xxcache
Host name for your Web host [heasarc.gsfc.nasa.gov]: /skyview3/local/lib
Processing begins.

Directory: /skyview/htdocs/cgi-bin/test/vo/ does not exist
Attempting to create: /skyview/htdocs/cgi-bin/test/vo/
Directory: /skyview/htdocs/cgi-bin/test/vo/datascope does not exist
Attempting to create: /skyview/htdocs/cgi-bin/test/vo/datascope
Directory: /skyview/htdocs/test/vo/ does not exist
Attempting to create: /skyview/htdocs/test/vo/
Directory: /skyview/htdocs/test/vo/datascope does not exist
Attempting to create: /skyview/htdocs/test/vo/datascope
Directory: /skyview/htdocs/test/vo/images does not exist
Attempting to create: /skyview/htdocs/test/vo/images
Directory: /skyview3/local/ does not exist
Attempting to create: /skyview3/local/
Directory: /skyview3/local/lib does not exist
Attempting to create: /skyview3/local/lib
Modifying CGI scripts
Updating: ./cgi-bin/vo/datascope/init.pl
    ** #!/www/server/vo/inst/bin/perl  ->  #!/skyview3/test/bin/perl
    ** use lib '/www/server/vo/inst/local/lib' ;  ->  use lib '/skyview3/local/lib' ;
Updating: ./cgi-bin/vo/datascope/cacheTee.pl
    ** #!/www/server/vo/inst/bin/perl  ->  #!/skyview3/test/bin/perl
    ** use lib '/www/server/vo/inst/local/lib' ;  ->  use lib '/skyview3/local/lib' ;
Updating: ./cgi-bin/vo/datascope/datascope.pl
    ** #!/www/server/vo/inst/bin/perl  ->  #!/skyview3/test/bin/perl
    ** use lib '/www/server/vo/inst/local/lib' ;  ->  use lib '/skyview3/local/lib' ;
Updating: ./cgi-bin/vo/datascope/process.pl
    ** #!/www/server/vo/inst/bin/perl  ->  #!/skyview3/test/bin/perl
    ** use lib '/www/server/vo/inst/local/lib' ;  ->  use lib '/skyview3/local/lib' ;
Updating: ./cgi-bin/vo/datascope/meta.pl
    ** #!/www/server/vo/inst/bin/perl  ->  #!/skyview3/test/bin/perl
    ** use lib '/www/server/vo/inst/local/lib' ;  ->  use lib '/skyview3/local/lib' ;
Modifying ./local/lib/VO/Util.pm
Copying: cp -r ./cgi-bin/vo/datascope/* /skyview/htdocs/cgi-bin/test/vo/datascope/*
Copying: cp -r ./vo/datascope/* /skyview/htdocs/test/vo/datascope/*
Copying: cp -r ./vo/images/* /skyview/htdocs/test/vo/images/*
Copying: cp -r ./local/lib/* /skyview3/local/lib/*
  
  
  
  
  There may be a few manual steps needed to complete your installation.
  

   The installation script assumes a consistent environment between
  the installation process and the running of CGI scripts in the Web environment.
  If the run-time environment is different from the install-time environment,
  then the executable paths and paths specified in the VO::Util module
  may need to be updated.
  
 The header and footer in the VO::Util module will need to be
  updated as appropriate for your site.
  
 The VO caching software assumes that the file is in a subdirectory
  of an htdocs directory that defines the top of the URL hierarchy
  for your browser.  E.g., if you are on host db.myhost.edu, and the cache
  is at /www/htdocs/vo/thecache, then a file /www/htdocs/vo/thecache/xxx can
  be accessed by a URL http://db.myhost.edu/vo/thecache/xxx.  The fixPrefixes methods
  in the Util module can be used to make ensure that the prefixes used are appropriate
  for your system.
  
 The cacheTee.pl program will generate quicklook images from FITS files
  using the command given in the $VO::fits2ql variable defined in the VO::Util
  module.  This variable should be set to an appropropriate value for the site.
  The HEASARC implementation using the FITS2jpeg software developed at NRAO
  but other converters can be used.  If a file type other than JPEG will
  be produced then the mime-type returned by the cacheTee program should
  also be changed.
  
  
  
   Setting up the cache 
  
  The cache area is where results from Cone search and SIAP requests will be stored.
  The cache will be written to from CGI scripts and thus needs to be set up with permissions
  that will allow scripts write access.  The contents of the cache directory must also
  be visible as URLs from outside of your site if you intend for users to be able to
  send data to external utilities like Aladin, VOStat or OASIS.  
  
  If you have superuser privileges creating the cache directory should
  not be a problem.  Without superuser privileges it can be done by creating
  a CGI script which will create the appropriate directories as a subdirectory of
  some existing directory that you own.  E.g.,
  

      Make the directory in which the cache directory will reside temporarily world writeable.
     
 Run a CGI script which creates the cache directory inside its parent.
     
 Change the permissions of the cache's parent directory back to their normal settings.
  
  
  A subdirectory will be created in the cache for each DataScope query which is started. 
  The name of the directory encodes the position and region size of the query.
  
   TBD 
  
  This document does not discuss the installation of the VOPlot applet or
  management utilities.