xcu_chap03.html

IEEE 1003.1-2003, Single Unix Specification v3

<h5><a name="tag_03_02_02_17"></a>Shell_Path_List Attribute</h5>

<p>The <i>Shell_Path_List</i> job attribute consists of a list of pairs of pathname and host name values. The host name component
can be omitted, in which case the pathname serves as the default pathname when a batch server cannot find the name of the host on
which it is running in the list.</p>

<p>A batch server that executes a batch job shall select, from the value of the <i>Shell_Path_List</i> attribute of the batch job,
a pathname where the shell to execute the batch job shall be found. The batch server shall select the pathname, in order of
preference, according to the following methods:</p>

<ul>
<li>
<p>Select the pathname that contains the name of the host on which the batch server is running.</p>
</li>

<li>
<p>Select the pathname for which the host name has been omitted.</p>
</li>

<li>
<p>Select the pathname for the login shell of the user under which the batch job is to execute.</p>
</li>
</ul>

<p>If the shell path value selected is an invalid pathname, the batch server shall abort the batch job.</p>

<p>If the value of the selected pathname from the <i>Shell_Path_List</i> attribute of the batch job represents a partial path, the
batch server shall expand the path relative to a path that is implementation-defined.</p>

<p>The batch server that executes the batch job shall execute the program that was selected from the <i>Shell_Path_List</i>
attribute of the batch job. The batch server shall pass the path to the script of the batch job as the first argument to the shell
program.</p>

<h5><a name="tag_03_02_02_18"></a>User_List Attribute</h5>

<p>The <i>User_List</i> job attribute consists of a list of pairs of user name and host name values. The host name component can be
omitted, in which case the user name serves as a default when a batch server cannot find the name of the host on which it is
running in the list.</p>

<p>A batch server that executes a batch job shall select, from the value of the <i>User_List</i> attribute of the batch job, a user
name under which to create the session leader. The server shall select the user name, in order of preference, according to the
following methods:</p>

<ul>
<li>
<p>Select the user name of a value that contains the name of the host on which the batch server executes.</p>
</li>

<li>
<p>Select the user name of a value for which the host name has been omitted.</p>
</li>

<li>
<p>Select the user name from the <i>Job_Owner</i> attribute of the batch job.</p>
</li>
</ul>

<h5><a name="tag_03_02_02_19"></a>Variable_List Attribute</h5>

<p>A batch server that executes a batch job shall create, in the environment of the session leader of the batch job, each
environment variable listed in the <i>Variable_List</i> attribute of the batch job, and set the value of each such environment
variable to that of the corresponding variable in the variable list.</p>

<h5><a name="tag_03_02_02_20"></a>Batch Job Routing</h5>

<p>To route a batch job is to select a queue from a list and move the batch job to that queue.</p>

<p>A batch server that has routing queues, which have been started, shall route the jobs in the routing queues owned by the batch
server. A batch server may delay the routing of a batch job. The algorithm for selecting a batch job and the queue to which it will
be routed is implementation-defined.</p>

<p>When a routing queue has multiple possible destinations specified, then the precedence of the destinations is
implementation-defined.</p>

<p>A batch server that routes a batch job to a queue at another server shall move the batch job into the target queue with a
<i>Queue Batch Job Request</i>.</p>

<p>If the target server rejects the <i>Queue Batch Job Request</i>, the routing server shall retry routing the batch job or abort
the batch job. A batch server that retries failed routings shall provide a means for the batch administrator to specify the number
of retries and the minimum period of time between retries. The means by which an administrator specifies the number of retries and
the delay between retries is implementation-defined. When the number of retries specified by the batch administrator has been
exhausted, the batch server shall abort the batch job and perform the functions of <i>Batch Job Exit</i>; see <a href=
"#tag_03_02_02_21">Batch Job Exit</a> .</p>

<h5><a name="tag_03_02_02_21"></a>Batch Job Exit</h5>

<p>For each job in the EXITING state, the batch server that exited the batch job shall perform the following deferred services in
the order specified:</p>

<ol>
<li>
<p>If buffering standard error, move that file into the location specified by the <i>Error_Path</i> attribute of the batch job.</p>
</li>

<li>
<p>If buffering standard output, move that file into the location specified by the <i>Output_Path</i> attribute of the batch
job.</p>
</li>

<li>
<p>If the <i>Mail_Points</i> attribute of the batch job includes MAIL_AT_EXIT, send mail to the users listed in the
<i>Mail_Users</i> attribute of the batch job. The mail message shall contain at least the batch job identifier, queue, and server
at which the batch job currently resides, and the <i>Job_Owner</i> attribute.</p>
</li>

<li>
<p>Remove the batch job from the queue.</p>
</li>
</ol>

<p>If a batch server that buffers the standard error output cannot return the standard error file to the standard error path at the
time the batch job exits, the batch server shall do one of the following:</p>

<ul>
<li>
<p>Mail the standard error file to the batch job owner.</p>
</li>

<li>
<p>Save the standard error file and mail the location and name of the file where the standard error is stored to the batch job
owner.</p>
</li>

<li>
<p>Save the standard error file and notify the user by other implementation-defined means.</p>
</li>
</ul>

<p>If a batch server that buffers the standard output cannot return the standard output file to the standard output path at the
time the batch job exits, the batch server shall do one of the following:</p>

<ul>
<li>
<p>Mail the standard output file to the batch job owner.</p>
</li>

<li>
<p>Save the standard output file and mail the location and name of the file where the standard output is stored to the batch job
owner.</p>
</li>

<li>
<p>Save the standard output file and notify the user by other implementation-defined means.</p>
</li>
</ul>

<p>At the conclusion of job exit processing, the batch job is no longer managed by a batch server.</p>

<h5><a name="tag_03_02_02_22"></a>Batch Server Restart</h5>

<p>A batch server that has been either shutdown or terminated abnormally, and has returned to operation, is said to have
``restarted''.</p>

<p>Upon restarting, a batch server shall requeue those jobs managed by the batch server that were in the RUNNING state at the time
the batch server shut down and for which the <i>Rerunable</i> attribute of the batch job has the value TRUE.</p>

<p>Queues are defined to be non-volatile. A batch server shall store the content of queues that it controls in such a way that
server and system shutdowns do not erase the content of the queues.</p>

<h5><a name="tag_03_02_02_23"></a>Batch Job Abort</h5>

<p>A batch server that cannot perform a deferred service for a batch job shall abort the batch job.</p>

<p>A batch server that aborts a batch job shall perform the following services:</p>

<ul>
<li>
<p>Delete the batch job from the queue in which it resides.</p>
</li>

<li>
<p>If the <i>Mail_Points</i> attribute of the batch job includes the value MAIL_AT_ABORT, send mail to the users listed in the
value of the <i>Mail_Users</i> attribute of the job. The mail message shall contain at least the batch job identifier, queue, and
server at which the batch job currently resides, the <i>Job_Owner</i> attribute, and the reason for the abort.</p>
</li>

<li>
<p>If the batch job was in the RUNNING state, terminate the session leader of the executing job by sending the session leader a
SIGKILL, place the batch job in the EXITING state, and perform the actions of <i>Batch Job Exit</i>.</p>
</li>
</ul>

<h4><a name="tag_03_02_03"></a>Requested Batch Services</h4>

<p>This section describes the services provided by batch servers in response to requests from clients. <a href="#tagtcjh_10">Batch
Services Summary</a> summarizes the current set of batch service requests and for each gives its type (deferred or not) and whether
it is an optional function.<br>
</p>

<center><b><a name="tagtcjh_10"></a> Table: Batch Services Summary</b></center>

<center>
<table border="1" cellpadding="3" align="center">
<tr valign="top">
<th align="center">
<p class="tent"><b>Batch Service</b></p>
</th>
<th align="center">
<p class="tent"><b>Deferred</b></p>
</th>
<th align="center">
<p class="tent"><b>Optional</b></p>
</th>
</tr>

<tr valign="top">
<td align="left">
<p class="tent"><i>Batch Job Execution</i></p>
</td>
<td align="center">
<p class="tent">Yes</p>
</td>
<td align="center">
<p class="tent">No</p>
</td>
</tr>

<tr valign="top">
<td align="left">
<p class="tent"><i>Batch Job Routing</i></p>
</td>
<td align="center">
<p class="tent">Yes</p>
</td>
<td align="center">
<p class="tent">No</p>
</td>
</tr>

<tr valign="top">
<td align="left">
<p class="tent"><i>Batch Job Exit</i></p>
</td>
<td align="center">
<p class="tent">Yes</p>
</td>
<td align="center">
<p class="tent">No</p>
</td>
</tr>

<tr valign="top">
<td align="left">
<p class="tent"><i>Batch Server Restart</i></p>
</td>
<td align="center">
<p class="tent">Yes</p>
</td>
<td align="center">
<p class="tent">No</p>
</td>
</tr>

<tr valign="top">
<td align="left">
<p class="tent"><i>Batch Job Abort</i></p>
</td>
<td align="center">
<p class="tent">Yes</p>
</td>
<td align="center">
<p class="tent">No</p>
</td>
</tr>

<tr valign="top">
<td align="left">
<p class="tent"><i>Delete Batch Job Request</i></p>
</td>
<td align="center">
<p class="tent">No</p>
</td>
<td align="center">
<p class="tent">No</p>
</td>
</tr>

<tr valign="top">
<td align="left">
<p class="tent"><i>Hold Batch Job Request</i></p>
</td>
<td align="center">
<p class="tent">No</p>
</td>
<td align="center">
<p class="tent">No</p>
</td>
</tr>

<tr valign="top">
<td align="left">
<p class="tent"><i>Batch Job Message Request</i></p>
</td>
<td align="center">
<p class="tent">No</p>
</td>
<td align="center">
<p class="tent">Yes</p>
</td>
</tr>

<tr valign="top">
<td align="left">
<p class="tent"><i>Batch Job Status Request</i></p>
</td>
<td align="center">
<p class="tent">No</p>
</td>
<td align="center">
<p class="tent">No</p>
</td>
</tr>

<tr valign="top">
<td align="left">
<p class="tent"><i>Locate Batch Job Request</i></p>
</td>
<td align="center">
<p class="tent">No</p>
</td>
<td align="center">
<p class="tent">Yes</p>
</td>
</tr>

<tr valign="top">
<td align="left">
<p class="tent"><i>Modify Batch Job Request</i></p>
</td>
<td align="center">
<p class="tent">No</p>
</td>
<td align="center">
<p class="tent">No</p>
</td>
</tr>

<tr valign="top">
<td align="left">
<p class="tent"><i>Move Batch Job Request</i></p>
</td>
<td align="center">
<p class="tent">No</p>
</td>
<td align="center">
<p class="tent">No</p>
</td>
</tr>

<tr valign="top">
<td align="left">
<p class="tent"><i>Queue Batch Job Request</i></p>
</td>
<td align="center">
<p class="tent">No</p>
</td>
<td align="center">
<p class="tent">No</p>
</td>
</tr>

<tr valign="top">
<td align="left">
<p class="tent"><i>Batch Queue Status Request</i></p>
</td>
<td align="center">
<p class="tent">No</p>
</td>
<td align="center">
<p class="tent">No</p>
</td>
</tr>

<tr valign="top">
<td align="left">
<p class="tent"><i>Release Batch Job Request</i></p>
</td>
<td align="center">
<p class="tent">No</p>
</td>
<td align="center">
<p class="tent">No</p>
</td>
</tr>

<tr valign="top">
<td align="left">
<p class="tent"><i>Rerun Batch Job Request</i></p>
</td>
<td align="center">
<p class="tent">No</p>
</td>
<td align="center">
<p class="tent">No</p>
</td>
</tr>

<tr valign="top">
<td align="left">
<p class="tent"><i>Select Batch Jobs Request</i></p>
</td>
<td align="center">
<p class="tent">No</p>
</td>
<td align="center">
<p class="tent">No</p>
</td>
</tr>

<tr valign="top">
<td align="left">
<p class="tent"><i>Server Shutdown Request</i></p>
</td>
<td align="center">
<p class="tent">No</p>
</td>
<td align="center">
<p class="tent">No</p>
</td>
</tr>

<tr valign="top">
<td align="left">
<p class="tent"><i>Server Status Request</i></p>
</td>
<td align="center">
<p class="t