Tapis-App Glossary

Tapis-App Glossary#

Glossary for New Tapis-App Users

This Glossary is Focused on DesignSafe + Stampede3 workflows

  • App

    A JSON definition describing what to run, how to run it, and what runtime environment is required. It is a template for creating Jobs.

  • Job

    An execution instance of an App with specified input files, parameters, and runtime arguments. A Job runs on the designated Execution System.

  • Execution System

    A Tapis-defined HPC or VM environment that runs jobs. Defines:

    • Scheduler (Slurm for TACC HPC)

    • Login method (SSH)

    • Filesystem paths (execDir, inputDir, outputDir)

    • Allowed runtimes (ZIP, Singularity)

    • Default modules (if applicable)

  • runtime

    Specifies how the application environment is provided:

    • ZIP — Unpacked scripts/binaries run in host environment

    • SINGULARITY — Run inside a .sif container image

    • DOCKER — Only supported on systems that allow Docker (not TACC HPC)

    Example:

    "runtime": "ZIP"

  • containerImage

    The source of the app’s runtime environment:

    • Path or URL to .zip/.tgz archive (ZIP runtime)

    • Path to .sif image (Singularity runtime)

    • Docker image reference (if DOCKER runtime allowed)

    Example (ZIP):

    "containerImage": "tapis://designsafe.storage/apps/opensees-sp.zip"

  • jobType

    Defines how the job is launched:

    • BATCH

      • Submitted through Slurm

      • Supports multi-node jobs

      • Used for OpenSeesSP/MP and most HPC workflows

    • FORK

      • Runs directly on host without scheduler

      • Single-node, lightweight tasks

    Example:

    "jobType": "BATCH"

  • execSystemExecDir

    Directory on the execution system where:

    • ZIP archives are unpacked

    • Singularity images may be copied

    • The job’s Slurm launch script is placed

    • The actual execution happens

    Essentially: the working directory for the running job.

  • execSystemInputDir

    Directory where Tapis stages all job inputs. This is a shared filesystem on TACC, so all compute nodes can read the same staged files.

  • execSystemOutputDir

    Directory where job output files are placed after completion. Tapis transfers files from here to the Job record’s “outputs” listing.

  • Input Staging

    The process by which Tapis:

    1. Creates job directory on the execution system

    2. Copies all referenced input files into it

    3. Ensures shared visibility across compute nodes

    On TACC HPC, input staging goes to the same shared storage visible from all nodes.

  • Parameter

    A primitive value passed into the app:

    • Numbers

    • Strings

    • Flags

    • Options

    Used for command-line arguments, filenames, counts, etc.

  • ArgString

    The final command that Tapis constructs using:

    • Executable

    • Parameters

    • Input references

    Example:

    OpenSeesMP model.tcl -n 48 -param 3.2

  • Scheduler Options

    Additional Slurm settings:

    • Queue/partition

    • Number of nodes

    • Cores per node

    • Wall time

    These can be specified in the App and sometimes overridden in the Job.

  • Apptainer / Singularity

    HPC container runtime used on TACC systems:

    • Unprivileged (safe for multi-user clusters)

    • Executes .sif images

    • Binds host directories into container

    Used for reproducible, environment-controlled apps.

  • Modules (TACC Environment Modules

    System-provided software components that can be loaded at runtime:

    module load hdf5
module load opensees
module load python

    ZIP runtime apps rely heavily on modules.

  • Shared Filesystem

    Parallel filesystem (e.g., /work2, /scratch) visible from all compute nodes. Ensures that multi-node jobs can access the same staged inputs without replication.