Package edu.isi.pegasus.planner.selector.site

Class NonJavaCallout

  • All Implemented Interfaces:
    SiteSelector
    public class NonJavaCallout
extends AbstractPerJob
    This is the class that implements a call-out to a site selector which is an application or executable script. In order to use the site selector implemented by this class, the property pegasus.selector.site must be set to value NonJavaCallout.

    This site selector implements a popen() like call to an external application that conforms to the API laid out here. The name of the application to run is specified by the property pegasus.selector.site.path. Its value points to a locally available application.

    If the external executable requires certain environment variables to be set for execution, these can be specified in the property files, using the prefix pegasus.selector.site.env . The name of the environment variable is obtained by stripping the prefix. For example, to set the variable PATH to a certain value, use the following entry in your user property file: 

       pegasus.selector.site.env.PATH = /usr/bin:/bin:/usr/X11R6/bin
    The site selector populates the environment of the external application with the following default properties, which can be overwritten by user-specified properties:
    keyvalue
    PEGASUS_HOME As set by the system
    CLASSPATH From java.class.path
    JAVA_HOME From java.home
    USER From user.name, if present
    LOGNAME From user.name, if present
    HOME From user.home, if present
    TMP From java.io.tmpdir, if present
    TZ From user.timezone, if present

    The user can specify the environment variables, by specifying the properties with the prefix pegasus.selector.site.env. prefix. for e.g user can override the default user.name property by setting the property pegasus.selector.site.env.user.home .

    The external application is invoked with one commandline argument. This argument is the name of a temporary file. The temporary file is created for each invocation anew by the site selecting caller. Being temporary, the file is deleted after the site selector returns with success. The deletion of the file is governed by the property pegasus.selector.site.keep.tmp. It can have a tristate value with the valid values being 

                  ALWAYS
              NEVER
              ONERROR

    The external application is expected to write one line to stdout. The line starts with the string SOLUTION:, followed by the chosen site handle. Optionally, separated by a colon, the name of a jobmanager for the site can be provided by the site selector. Two examples for successful site selections are: 

       SOLUTION:mysite:my.job.mgr/jobmanager-batch
   SOLUTION:siteY
    Note, these are two examples. The site selector only returns one line with the appropriate solution. If no site is found to be eligble, the poolhandle should be set to NONE by the site selector.

    The temporary file is the corner stone of the communication between the site selecting caller and the external site selector. It is a collection of key-value pairs. Each pair is separated by an equals (=) sign, and stands on a line of its own. There are no multi-line values permitted.

    The following pairs are generated for the siteselector temporary file:

    #keyvalue
    1version The version of the site selector API, currently 2.0
    1transformation The fully-qualified definition identifier for the TR, ns::id:vs.
    1derivation The fully-qualified definition identifier for the DV, ns::id:vs.
    1job.level The job's depth in the DFS tree of the workflow DAG
    1job.id The job's ID, as used in the DAX file.
    Nresource.id A pool handle, followed by a whitespace, followed by a gridftp server. Typically, each gridftp server is enumerated once, so you may have multiple occurances of the same site.
    Minput.lfn An input LFN, optionally followed by a whitespace and filesize.
    1wf.name The label of the DAX, as found in the DAX's root element.
    1wf.index The DAX index, which is incremented for each partition.
    1wf.time The mtime of the workflow.
    1wf.manager The name of the workflow manager to be used, e.g. dagman.
    1vo.name unused at present, name of the virtual organization who runs this WF.
    1vo.group unused at present, usage not clear .

    In order to detect malfunctioning site selectors, a timeout is attached with each site selector, see property pegasus.selector.site.timeout. By default, a site selector is given up upon after 60 s.

    Version:
    $Revision$
    Author:
    Karan Vahi, Jens Vöckler
    See Also:
    Runtime, Process

    • Field Summary

      Fields 
      Modifier and Type Field Description
      static int KEEP_ALWAYS
      The state denoting always to keep the temporary files.
      static int KEEP_NEVER
      The state denoting never to keep the temporary files.
      static int KEEP_ONERROR
      The state denoting to keep the temporary files only in case of error.
      private edu.isi.pegasus.planner.classes.ADag mAbstractDag
      The abstract DAG.
      private static java.lang.String mDescription
      The description of the site selector.
      private java.util.Map mEnvVar
      The map that contains the environment variables including the default ones that are set while calling out to the site selector unless they are overridden by the values set in the properties file.
      private int mKeepTMP
      The tristate value for whether keeping the temporary files generated or not.
      private java.lang.String mSiteSelectorPath
      The path to the site selector.
      private int mTimeout
      The timeout value in seconds after which to timeout, in the case where the external site selector does nothing (nothing on stdout nor stderr).
      static java.lang.String PREFIX_PROPERTIES
      The prefix of the property names that specify the environment variables that need to be set before calling out to the site selector.
      static java.lang.String PREFIX_TEMPORARY_FILE
      The prefix to be used while creating a temporary file to pass to the external siteselector.
      static java.lang.String SOLUTION_PREFIX
      The prefix that the site selector writes out on its stdout to designate that it is sending a solution.
      static java.lang.String SUFFIX_TEMPORARY_FILE
      The suffix to be used while creating a temporary file to pass to the external siteselector.
      static java.lang.String VERSION
      The version number associated with this API of non java callout site selection.

    • Constructor Summary

      Constructors 
      Constructor Description
      NonJavaCallout()
      The default constructor.

    • Method Summary

      All Methods Static Methods Instance Methods Concrete Methods 
      Modifier and Type Method Description
      java.lang.String description()
      Returns a brief description of the site selection technique implemented by this class.
      private java.lang.String[] getEnvArrFromMap()
      Generates an array of environment variables.
      private int getKeepTMPValue​(java.lang.String value)
      Returns the int value corresponding to the string value passed.
      private java.lang.String getTempFilename()
      Creates a temporary file and obtains its name.
      void initialize​(edu.isi.pegasus.planner.classes.PegasusBag bag)
      Initializes the site selector.
      private void loadEnvironmentVariables()
      Initializes the internal hash that collects environment variables.
      static void main​(java.lang.String[] args)
      The main program that allows you to test.
      void mapJob​(edu.isi.pegasus.planner.classes.Job job, java.util.List sites)
      Calls out to the external site selector.
      void mapWorkflow​(edu.isi.pegasus.planner.classes.ADag workflow, java.util.List sites)
      Maps the jobs in the workflow to the various grid sites.
      private boolean parseStdOut​(edu.isi.pegasus.planner.classes.Job job, java.lang.String s)
      Extracts the chosen site from the site selector's answer.
      private java.io.File prepareInputFile​(edu.isi.pegasus.planner.classes.Job job, java.util.List pools)
      Writes job knowledge into the temporary file passed to the external site selector.

      • Methods inherited from class java.lang.Object

        clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

    • Field Detail

      • PREFIX_TEMPORARY_FILE

        public static final java.lang.String PREFIX_TEMPORARY_FILE
        The prefix to be used while creating a temporary file to pass to the external siteselector.
        See Also:
        Constant Field Values

      • SUFFIX_TEMPORARY_FILE

        public static final java.lang.String SUFFIX_TEMPORARY_FILE
        The suffix to be used while creating a temporary file to pass to the external siteselector.

      • PREFIX_PROPERTIES

        public static final java.lang.String PREFIX_PROPERTIES
        The prefix of the property names that specify the environment variables that need to be set before calling out to the site selector.
        See Also:
        Constant Field Values

      • SOLUTION_PREFIX

        public static final java.lang.String SOLUTION_PREFIX
        The prefix that the site selector writes out on its stdout to designate that it is sending a solution.
        See Also:
        Constant Field Values

      • VERSION

        public static final java.lang.String VERSION
        The version number associated with this API of non java callout site selection.
        See Also:
        Constant Field Values

      • KEEP_NEVER

        public static final int KEEP_NEVER
        The state denoting never to keep the temporary files.
        See Also:
        Constant Field Values

      • KEEP_ONERROR

        public static final int KEEP_ONERROR
        The state denoting to keep the temporary files only in case of error.
        See Also:
        Constant Field Values

      • KEEP_ALWAYS

        public static final int KEEP_ALWAYS
        The state denoting always to keep the temporary files.
        See Also:
        Constant Field Values

      • mDescription

        private static final java.lang.String mDescription
        The description of the site selector.
        See Also:
        Constant Field Values

      • mEnvVar

        private java.util.Map mEnvVar
        The map that contains the environment variables including the default ones that are set while calling out to the site selector unless they are overridden by the values set in the properties file.

      • mTimeout

        private int mTimeout
        The timeout value in seconds after which to timeout, in the case where the external site selector does nothing (nothing on stdout nor stderr).

      • mKeepTMP

        private int mKeepTMP
        The tristate value for whether keeping the temporary files generated or not.

      • mSiteSelectorPath

        private java.lang.String mSiteSelectorPath
        The path to the site selector.

      • mAbstractDag

        private edu.isi.pegasus.planner.classes.ADag mAbstractDag
        The abstract DAG.

    • Constructor Detail

      • NonJavaCallout

        public NonJavaCallout()
        The default constructor.

    • Method Detail

      • initialize

        public void initialize​(edu.isi.pegasus.planner.classes.PegasusBag bag)
        Initializes the site selector.
        Specified by:
        initialize in interface SiteSelector
        Overrides:
        initialize in class Abstract
        Parameters:
        bag - the bag of objects that is useful for initialization.

      • mapWorkflow

        public void mapWorkflow​(edu.isi.pegasus.planner.classes.ADag workflow,
                        java.util.List sites)
        Maps the jobs in the workflow to the various grid sites. The jobs are mapped by setting the site handle for the jobs.
        Specified by:
        mapWorkflow in interface SiteSelector
        Overrides:
        mapWorkflow in class AbstractPerJob
        Parameters:
        workflow - the workflow.
        sites - the list of String objects representing the execution sites that can be used.

      • description

        public java.lang.String description()
        Returns a brief description of the site selection technique implemented by this class.
        Returns:
        a self-description of this site selector.

      • mapJob

        public void mapJob​(edu.isi.pegasus.planner.classes.Job job,
                   java.util.List sites)
        Calls out to the external site selector. The method converts a Job object into an API-compliant temporary file. The file's name is provided as single commandline argument to the site selector executable when it is invoked. The executable, representing the external site selector, provides its answer on stdout. The answer is captures, and returned.
        Specified by:
        mapJob in class AbstractPerJob
        Parameters:
        job - is a representation of the DAX compute job whose site of execution need to be determined.
        sites - the list of String objects representing the execution sites that can be used.

        FIXME: Some site selector return an empty string on failures. Also: NONE could be a valid site name.

        See Also:
        Job

      • prepareInputFile

        private java.io.File prepareInputFile​(edu.isi.pegasus.planner.classes.Job job,
                                      java.util.List pools)
        Writes job knowledge into the temporary file passed to the external site selector. The job knowledge derives from the contents of the DAX job's Job record, and the a list of site candidates. The format of the file is laid out in the class's introductory documentation.
        Parameters:
        job - is a representation of the DAX compute job whose site of execution need to be determined.
        pools - is a list of site candidates. The items of the list are String objects.
        Returns:
        the temporary input file was successfully prepared. A value of null implies that an error occured while writing the file.
        See Also:
        getTempFilename()

      • parseStdOut

        private boolean parseStdOut​(edu.isi.pegasus.planner.classes.Job job,
                            java.lang.String s)
        Extracts the chosen site from the site selector's answer. Parses the stdout sent by the selector, to see, if the execution pool and the jobmanager were sent or not.
        Parameters:
        job - the job that has to be mapped.
        s - is the stdout received from the site selector.
        Returns:
        boolean indicating if the stdout was succesfully parsed and job populated.

      • getTempFilename

        private java.lang.String getTempFilename()
        Creates a temporary file and obtains its name. This method returns the absolute path to a temporary file in the system's TEMP directory. The file is guarenteed to be unique for the current invocation of the virtual machine.

        FIXME: However, since we return a filename and not an opened file, race conditions are still possible.

        Returns:
        the absolute path of a newly created temporary file.

      • loadEnvironmentVariables

        private void loadEnvironmentVariables()
        Initializes the internal hash that collects environment variables. These variables are set up to run the external helper application. Environment variables come from two source.
        1. Default environment variables, fixed, hard-coded.
        2. User environment variables, from properties.

      • getEnvArrFromMap

        private java.lang.String[] getEnvArrFromMap()
        Generates an array of environment variables. The variables are kept in an internal map. Converts the environment variables in the map to the array format.
        Returns:
        array of enviroment variables set, or null if the map is empty.
        See Also:
        loadEnvironmentVariables()

      • getKeepTMPValue

        private int getKeepTMPValue​(java.lang.String value)
        Returns the int value corresponding to the string value passed.
        Parameters:
        value - the string value for keeping the temporary files.
        Returns:
        the corresponding int value.
        See Also:
        KEEP_ALWAYS, KEEP_NEVER, KEEP_ONERROR

      • main

        public static void main​(java.lang.String[] args)
        The main program that allows you to test. FIXME: Test programs should have prefix Test.....java
        Parameters:
        args - the arguments