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Execution Environment
enFuzion Lite
Standard Input, Standard Output and Standard Error
The
The Dispatcher can be started from the main enFuzion menu or from a command
line as:
The execution can be started by using the
Dispatcher will not exit after the run is finished.
With this option a client can use the director API after all jobs
are finished.
Dispatcher exits when it receives the
When Dispatcher is executed in batch mode, all passwords must be
specified in file
This option is used to safely set the working directory, for
example when Dispatcher is executed using a scripting language or
from a Java class.
Square icons display the status of individual jobs. Each job can be either
waiting for execution, executing, completed successfully or completed
with failure. Job icons are explained in detail in Table 1.
Table 1. Dispatcher Icons
The window allows you to manually change the status of a job.
These changes will be carried out regardless of the current job status.
If the job is executing, it will be terminated.
The
During execution, the
A log example is shown in Figure 7.6. The log shows details
about the execution progress. The log will also show any errors that
are encountered. At the end, the log contains a summary of the run.
Executables for your applications that are executed on remote computers
by enFuzion Nodes
must be available on these computers and included in the execution search
path. If enFuzion is unable to locate an executable file, it will report an
error.
enFuzion does not assume a shared file system. It will transfer files between
the root and the node computer as specified in the plan.
When enFuzion starts a job on a remote computer, it creates a unique directory
in the remote file system. All relative file names start from that directory.
This unique directory makes it possible to run multiple concurrent copies
of a job on the same computer or in the same shared files system without
conflicting file names between jobs. For example, each job can write to
a file called "output". Although all jobs use the same file name, the file
is unique for each job.
On the root computer, all file references are relative to the directory
in which the
If files are copied to the node in the
enFuzion Lite is not available on the Windows NT platform.
User commands can use standard input, standard output and standard error.
These can be either redirected to files with shell redirection constructs
or left unspecified.
If they are unspecified, enFuzion will automatically redirect standard input to
"stdin", standard output to "stdout", and standard error to "stderr".
These regular files can be handled with standard commands for file
manipulation.
System errors are caused by computer or network failures. If a node fails,
jobs executing on that node are automatically restarted elsewhere. No user
intervention is required. If the root computer fails, then the Dispatcher
must be restarted.
User errors are caused by missing files or user commands that return a
nonzero exit status. The handling of these errors can be specified with the
If a job fails on a node computer, either because the user application fails
or one of the enFuzion commands detects an error, then enFuzion automatically
copies the entire job directory from the node to the root. The directory
is named
The Dispatcher
Dispatcher is the central enFuzion component, responsible
for executing the jobs. The Dispatcher accepts a run file with a description
of jobs and their parameters. It initiates and manages the execution.
Dispatcher Parameters
enfdispatcher [ -v ] [ -a ] [ -b ] [ -e ] [ -i ] [ -p <port number> ]
[-w <path>] [ <run name> ]
The following parameters are recognized by the Dispatcher:
-v
If this is the first parameter, then the Dispatcher prints out its version
and exits.
-a
The parameter specifies that the Dispatcher will be executed without
the graphical user interface. Dispatcher will take a run file as input,
but will not start the execution.
start API
command.
exit API command.
-b
This parameter specifies that the Dispatcher is executed in batch mode
without any graphical user interface. In batch mode, the Dispatcher
takes a run file as input and automatically starts the execution.
If all the jobs complete successfully, the Dispatcher returns 0
as its exit value. If some of the jobs fail, the Dispatcher returns 1 as
its exit value.
enfuzion.nodes.
-e
The Dispatcher produces a network configuration file with encrypted
passwords. Details are described in
Encrypted Passwords in enfuzion.nodes.
-i
Dispatcher is started with its window iconified.
-p <port number>
Dispatcher's port for application programming interface is opened
at <port number>. Otherwise, a system supplied port is being
used. The application programming interface is described in
Using Application Programming Interface.
-w <path>
Dispatcher will set its working directory to path.
The working directory contains enFuzion configuration and
log files.
<run name>
Specifies the name of the input file with a run description for jobs.
Dispatcher Window
The Dispatcher displays a graphical display of the
execution status and its progress.
An example of the Dispatcher screen is shown in Figure 7.1.
Figure 7.1. Dispatcher Main Window
The button in the upper right corner allows you to Start, Stop or Resume
the execution. The upper three lines display the progress of the execution,
containing a summary of main execution parameters.
The job is waiting for execution.
The job is executing.
The job has completed successfully.
The job has failed. A job fails, if a user
application returned a non zero status, or if one of the enFuzion commands
failed. For example, a Copy task command was unable to find the source file.
By clicking on a job icon, you can open a job window.
The lower left corner of the Dispatcher window shows the job selected.
The job window contains details about the job. It is described in the
next section.
Job Window
The job window contains details about the job. It is opened by clicking
on the job icon in the Dispatcher window. An example of a job window is
shown in Figure 7.2.
Figure 7.2. Status of a single job.
<Run next> button schedules the job as the
next job to start executing.
<Done - OK> button labels the job as completed
successfully.
<Done - Failed> button labels the job as completed
with failure.
Dispatcher Commands
Statistics menu allows you to obtain information on different
aspects of execution.
Option View Jobs shows the information on the execution of
individual jobs. An example is shown in Figure 7.3.
Figure 7.3. View of Jobs
The Server display shows the current state of each computational node,
as shown in Figure 7.4.
Figure 7.4. View of Servers
The Parameter display shows the parameter values for each job,
as shown in Figure 7.5.
Figure 7.5. View of Parameter Values
Options Save Jobs, Save Servers,
Save Parameters and Save Log in menu
Statistics allow you to store the corresponding information
to a file.
Dispatcher Log
Dispatcher produces a log,
describing major execution events. The log is saved to file
enfuzion.log as well as displayed on standard output.
If an old enfuzion.log already exists, a unique suffix is added
to the file name. This preserves all old Dispatcher logs.
Figure 7.6. enFuzion Log
Execution Environment
Dispatcher has been started.
When a file is copied from a node to the local computer, it is usually
renamed to include a unique identifier. The renaming can be done by
using a system defined parameter, called $jobname, which is unique for each
job or by using a combination of parameter values. The
Preparator provides an easy way to specify the renaming of
output files.
nodestart task,
then the copying is performed before any of the user jobs starts on that node.
These files are common to all jobs. When each job starts executing, the
common files are made available to the job. A set of input files, which is
common to all jobs, can be thus copied only once to each node. This
feature significantly reduces network traffic, if common input files are
large.
enFuzion Lite
enFuzion Lite has the same features as standard enFuzion. However, jobs are
executed only on the local machine. enFuzion Lite does not support distributed
execution of jobs.
enFuzion Lite is available in the following cases:
enFuzion Lite can be upgraded to standard enFuzion by providing a valid
license.
enflicense does not exist.
enfuzion.nodes does not exist.
Standard Input, Standard Output and Standard Error
Handling of Execution Errors
enFuzion distinguishes two types of errors, system errors and user errors.
onerror command .
Jobs with user errors can either fail, be repeated on a different computer or
continue with the execution, depending on the user specified option.
error.$jobname, where $jobname is
replaced with the name of the job. The ability to inspect the contents of
the remote directory significantly simplifies error diagnosis.
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