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   qalter.1p    ( 1 )

изменить пакетное задание (alter batch job)

Обоснование (Rationale)

The qalter utility allows users to change the attributes of a batch job.

As a means of altering a queued job, the qalter utility is superior to deleting and requeuing the batch job insofar as an altered job retains its place in the queue with some traditional selection algorithms. In addition, the qalter utility is both shorter and simpler than a sequence of qdel and qsub utilities.

The result of an attempt on the part of a user to alter a batch job in a RUNNING state is implementation-defined because a batch job in the RUNNING state will already have opened its output files and otherwise performed any actions indicated by the options in effect at the time the batch job began execution.

The options processed by the qalter utility are identical to those of the qsub utility, with a few exceptions: -V, -v, and -q. The -V and -v are inappropriate for the qalter utility, since they capture potentially transient environment information from the submitting process. The -q option would specify a new queue, which would largely negate the previously stated advantage of using qalter; furthermore, the qmove utility provides a superior means of moving jobs.

Each of the following paragraphs provides the rationale for a qalter option.

Additional rationale concerning these options can be found in the rationale for the qsub utility.

The -a option allows users to alter the date and time at which a batch job becomes eligible to run.

The -A option allows users to change the account that will be charged for the resources consumed by the batch job. Support for the -A option is mandatory for conforming implementations of qalter, even though support of accounting is optional for servers. Whether or not to support accounting is left to the implementor of the server, but mandatory support of the -A option assures users of a consistent interface and allows them to control accounting on servers that support accounting.

The -c option allows users to alter the checkpointing interval of a batch job. A checkpointing system, which is not defined by POSIX.1‐2008, allows recovery of a batch job at the most recent checkpoint in the event of a crash. Checkpointing is typically used for jobs that consume expensive computing time or must meet a critical schedule. Users should be allowed to make the tradeoff between the overhead of checkpointing and the risk to the timely completion of the batch job; therefore, this volume of POSIX.1‐2017 provides the checkpointing interval option. Support for checkpointing is optional for servers.

The -e option allows users to alter the name and location of the standard error stream written by a batch job. However, the path of the standard error stream is meaningless if the value of the Join_Path attribute of the batch job is TRUE.

The -h option allows users to set the hold type in the Hold_Types attribute of a batch job. The qhold and qrls utilities add or remove hold types to the Hold_Types attribute, respectively. The -h option has been modified to allow for implementation-defined hold types.

The -j option allows users to alter the decision to join (merge) the standard error stream of the batch job with the standard output stream of the batch job.

The -l option allows users to change the resource limits imposed on a batch job.

The -m option allows users to modify the list of points in the life of a batch job at which the designated users will receive mail notification.

The -M option allows users to alter the list of users who will receive notification about events in the life of a batch job.

The -N option allows users to change the name of a batch job.

The -o option allows users to alter the name and path to which the standard output stream of the batch job will be written.

The -P option allows users to modify the priority of a batch job. Support for priority is optional for batch servers.

The -r option allows users to alter the rerunability status of a batch job.

The -S option allows users to change the name and location of the shell image that will be invoked to interpret the script of the batch job. This option has been modified to allow a list of shell name and locations associated with different hosts.

The -u option allows users to change the user identifier under which the batch job will execute.

The job_identifier operand syntax is provided so that the user can differentiate between the originating and destination (or executing) batch server. These may or may not be the same. The .server_name portion identifies the originating batch server, while the @server portion identifies the destination batch server.

Historically, the qalter utility has been a component of the Network Queuing System (NQS), the existing practice from which this utility has been derived.