Glossary of Batch System Terms
- Account
- is an arbitrary character string which may have meaning to one or more hosts in the batch system. Frequently, account is used as a grouping for charging for the use of resources.
- Administrator
- See Manager.
- Attribute
- is an inherent characteristic of the parent object. Typically, this is a data item whose value affects the operation or behavior of the object and is settable by owner of the object. For example, the user may supply values for attributes of a job.
- Batch
- or batch processing, is the capability of running jobs outside of the interactive login session. In this document, batch implies a more complex subsystem which provides for additional control over job scheduling and resource contention.
- Batch Server
- is a persistent subsystem (daemon) upon a single host which provides batch processing capability.
- Batch System
- is a set of batch servers that are configured for processing. The system may consist of multiple hosts, each with multiple servers.
- Cluster
- is a set of execution "servers" or hosts on which a single batch server manages batch jobs. A cluster may be made up of a set of workstations, multiple cpu systems, or a set of nodes in a parallel system.
- Complex
- or queue complex in NQS was a set of queues within a batch server. The purpose of a complex was to provide additional control over resource usage. The advanced scheduling features of PBS eliminates the requirement for complexes.
- Destination
- is the location within the batch system where the job is sent for processing or executing. In PBS, a destination may uniquely define a single queue at a single batch server or it may map into many locations.
- Destination Identifier
- is a string which names the destination. It is in two parts and has the format
queue@server
where server is the name of a batch server and queue is the string identifying a queue on that server.
File Staging
is the movement of files between a specified location and the execution host. See "Stage In" and "Stage Out" .
Group
is a collection of system users (see Users). A user must be a member of a group and may be a member of more than one. Within Unix and POSIX systems, membership in a group establishes one level of privilege. Group membership is also often used to control or limit access to system resources.
Hold
is an artificial restriction which prevents a job from being selected for processing. There are three types of holds, which is applied by the job owner, (or operator) which is applied by the batch operator or administrator, and which is applied by the system itself or the batch system administrator.
Job
or batch job is the basic execution object managed by the batch subsystem. A job is a collection of related processes which is managed as a whole. A job can often be thought of as a shell script. In POSIX terms, a job is a session group. A session is a processes group the member processes cannot leave.
Manager
or Batch System Manager is a person authorized to use all restricted capabilities of the batch system. The manager may act upon the batch system, queues, or jobs. Also called the administrator.
Operator
or Batch Operator is a person authorized to use some but not all of the restricted capabilities of the batch system.
Owner
of a job is the user who submitted the job to the batch system.
PBS
is short for Portable Batch System.
POSIXrefers to the various standards being developed by the "Technical Committee on Operating Systems and Application Environments of the IEEE Computer Society" under standard P1003. There are a number of subcommittees under POSIX, those of interest to this project are:
- POSIX.1
- System Application Program Interface (the system calls).
- POSIX.2
- The command shell language.
- POSIX.3
- Test Methods
- POSIX.10
- Super Computing Profile
- POSIX.12
- Protocol Independent Interfaces (one of the many network working groups)
- POSIX.14
- Multiprocessor Working Group
- POSIX.15
- Batch Queuing Extensions. This standard has been approved as 1003.2d.
Queue
is a collection of jobs (or job related tasks) within the batch queuing system. Each queue has a set of associated attributes which determine what actions are performed upon each job within the queue. Typical attributes include queue name, queue priority, resource limits, destination(s) and job count limits. Selection/scheduling of jobs is implementation defined. The use of the term "queue" does not imply the ordering is "first in, first out."
Rerunable
If a batch job can be terminated and its execution restarted from the beginning without harmful side effects, then the job is said to be rerunable.
Stage In
is to move a file or files to the host prior to the batch job beginning execution.
Stage Out
is to move a file or files off of the host after the batch job completes execution.
User is a user of the compute system. Each user is identified by a unique character string, the user name; and by a unique number, the user id.
User ID
is a numeric identifier uniquely assigned to each user. Privilege to access system resources and services is typically established by the user id.
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